org.apache.maven.shared.utils.io

Class IOUtil

java.lang.Object

org.apache.maven.shared.utils.io.IOUtil

public final class IOUtil
extends java.lang.Object

General IO Stream manipulation.

This class provides static utility methods for input/output operations, particularly buffered copying between sources (InputStream, Reader, String and byte[]) and destinations (OutputStream, Writer, String and byte[]).

Unless otherwise noted, these copy methods do not flush or close the streams. Often, doing so would require making non-portable assumptions about the streams' origin and further use. This means that both streams' close() methods must be called after copying. if one omits this step, then the stream resources (sockets, file descriptors) are released when the associated Stream is garbage-collected. It is not a good idea to rely on this mechanism.

For each copy method, a variant is provided that allows the caller to specify the buffer size (the default is 4k). As the buffer size can have a fairly large impact on speed, this may be worth tweaking. Often "large buffer -> faster" does not hold, even for large data transfers.

For byte-to-char methods, a copy variant allows the encoding to be selected (otherwise the platform default is used).

The copy methods use an internal buffer when copying. It is therefore advisable not to deliberately wrap the stream arguments to the copy methods in Buffered* streams. For example, don't do the following:

copy( new BufferedInputStream( in ), new BufferedOutputStream( out ) );

The rationale is as follows:

Imagine that an InputStream's read() is a very expensive operation, which would usually suggest wrapping in a BufferedInputStream. The BufferedInputStream works by issuing infrequent InputStream.read(byte[] b, int off, int len) requests on the underlying InputStream, to fill an internal buffer, from which further read requests can inexpensively get their data (until the buffer runs out).

However, the copy methods do the same thing, keeping an internal buffer, populated by InputStream.read(byte[] b, int off, int len) requests. Having two buffers (or three if the destination stream is also buffered) is pointless, and the unnecessary buffer management hurts performance slightly (about 3%, according to some simple experiments).

Version:

CVS $Revision$ $Date$

Field Summary

Fields

Modifier and Type	Field and Description
private static int	DEFAULT_BUFFER_SIZE

Constructor Summary

Constructors

Modifier	Constructor and Description
private	IOUtil() Private constructor to prevent instantiation.

Method Summary

Modifier and Type	Method and Description
static void	close(java.nio.channels.Channel channel) Deprecated. use try-with-resources
static void	close(java.io.InputStream inputStream) Deprecated. use try-with-resources
static void	close(java.io.OutputStream outputStream) Deprecated. use try-with-resources
static void	close(java.io.Reader reader) Deprecated. use try-with-resources
static void	close(java.io.Writer writer) Deprecated. use try-with-resources
static boolean	contentEquals(java.io.InputStream input1, java.io.InputStream input2) Deprecated. use org.apache.commons.io.IOUtils.contentEquals()
static void	copy(byte[] input, java.io.OutputStream output) Deprecated. inline this method
static void	copy(byte[] input, java.io.Writer output) Deprecated. always specify a character encoding
static void	copy(byte[] input, java.io.Writer output, int bufferSize) Deprecated. always specify a character encoding
static void	copy(byte[] input, java.io.Writer output, java.lang.String encoding) Deprecated. use org.apache.commons.io.IOUtils.write().
static void	copy(byte[] input, java.io.Writer output, java.lang.String encoding, int bufferSize) Deprecated. use org.apache.commons.io.IOUtils.write().
static void	copy(java.io.InputStream input, java.io.OutputStream output) Deprecated. use org.apache.commons.io.IOUtils.copy() or in Java 9 and later InputStream.transferTo().
static void	copy(java.io.InputStream input, java.io.OutputStream output, int bufferSize) Deprecated. use org.apache.commons.io.IOUtils.copy() or in Java 9 and later InputStream.transferTo().
static void	copy(java.io.InputStream input, java.io.Writer output) Deprecated. use org.apache.commons.io.IOUtils.copy().
static void	copy(java.io.InputStream input, java.io.Writer output, int bufferSize) Deprecated. use org.apache.commons.io.IOUtils.copy().
static void	copy(java.io.InputStream input, java.io.Writer output, java.lang.String encoding) Deprecated. use org.apache.commons.io.IOUtils.copy().
static void	copy(java.io.InputStream input, java.io.Writer output, java.lang.String encoding, int bufferSize) Deprecated. use org.apache.commons.io.IOUtils.copy().
static void	copy(java.io.Reader input, java.io.OutputStream output) Deprecated. always specify a character encoding
static void	copy(java.io.Reader input, java.io.OutputStream output, int bufferSize) Deprecated. always specify a character encoding
static void	copy(java.io.Reader input, java.io.Writer output) Deprecated.
static void	copy(java.io.Reader input, java.io.Writer output, int bufferSize) Deprecated. use org.apache.commons.io.IOUtils.copy().
static void	copy(java.lang.String input, java.io.OutputStream output) Deprecated. always specify a character encoding
static void	copy(java.lang.String input, java.io.OutputStream output, int bufferSize) Deprecated. always specify a character encoding
static void	copy(java.lang.String input, java.io.Writer output) Deprecated. use org.apache.commons.io.IOUtils.write().
static byte[]	toByteArray(java.io.InputStream input) Deprecated. use org.apache.commons.io.IOUtils.readFully().
static byte[]	toByteArray(java.io.InputStream input, int bufferSize) Deprecated. use org.apache.commons.io.IOUtils.readFully().
static byte[]	toByteArray(java.io.Reader input) Deprecated. always specify a character encoding
static byte[]	toByteArray(java.io.Reader input, int bufferSize) Deprecated. always specify a character encoding
static byte[]	toByteArray(java.lang.String input) Deprecated. always specify a character encoding
static byte[]	toByteArray(java.lang.String input, int bufferSize) Deprecated. always specify a character encoding
static java.lang.String	toString(byte[] input) Deprecated. always specify a character encoding
static java.lang.String	toString(byte[] input, int bufferSize) Deprecated. always specify a character encoding
static java.lang.String	toString(byte[] input, java.lang.String encoding) Deprecated. use new String(input, encoding)
static java.lang.String	toString(byte[] input, java.lang.String encoding, int bufferSize) Deprecated. use new String(input, encoding)
static java.lang.String	toString(java.io.InputStream input) Deprecated. always specify a character encoding
static java.lang.String	toString(java.io.InputStream input, int bufferSize) Deprecated. always specify a character encoding
static java.lang.String	toString(java.io.InputStream input, java.lang.String encoding) Deprecated. use org.apache.commons.io.IOUtils.toString().
static java.lang.String	toString(java.io.InputStream input, java.lang.String encoding, int bufferSize) Deprecated. use org.apache.commons.io.IOUtils.toString().
static java.lang.String	toString(java.io.Reader input) Deprecated. use org.apache.commons.io.IOUtils.toString().
static java.lang.String	toString(java.io.Reader input, int bufferSize) Deprecated. use org.apache.commons.io.IOUtils.toString().

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_BUFFER_SIZE

private static final int DEFAULT_BUFFER_SIZE

See Also:

Constant Field Values

Constructor Detail

IOUtil

private IOUtil()

Private constructor to prevent instantiation.

Method Detail

copy

@Deprecated
public static void copy(@Nonnull
                                    java.io.InputStream input,
                                    @Nonnull
                                    java.io.OutputStream output)
                             throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.copy() or in Java 9 and later InputStream.transferTo().

Copy bytes from an InputStream to an OutputStream.

Parameters:

input - the stream to read from

output - the stream to write to

Throws:

java.io.IOException - in case of an error

copy

@Deprecated
public static void copy(@Nonnull
                                    java.io.InputStream input,
                                    @Nonnull
                                    java.io.OutputStream output,
                                    int bufferSize)
                             throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.copy() or in Java 9 and later InputStream.transferTo().

Copy bytes from an InputStream to an OutputStream. In Java 9 and later this is replaced by InputStream.transferTo().

Parameters:

input - the stream to read from

output - the stream to write to

bufferSize - size of internal buffer

Throws:

java.io.IOException - in case of an error

copy

@Deprecated
public static void copy(@Nonnull
                                    java.io.Reader input,
                                    @Nonnull
                                    java.io.Writer output)
                             throws java.io.IOException

Deprecated.

Copy chars from a Reader to a Writer.

Parameters:

input - the reader to read from

output - the writer to write to

Throws:

java.io.IOException - in case of failure * @deprecated use org.apache.commons.io.IOUtils.copy().

copy

@Deprecated
public static void copy(@Nonnull
                                    java.io.Reader input,
                                    @Nonnull
                                    java.io.Writer output,
                                    int bufferSize)
                             throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.copy().

Copy chars from a Reader to a Writer.

Parameters:

input - the reader to read from

output - the writer to write to

bufferSize - size of internal buffer

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    java.io.InputStream input,
                                    @Nonnull
                                    java.io.Writer output)
                             throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.copy().

Copy and convert bytes from an InputStream to chars on a Writer. The platform's default encoding is used for the byte-to-char conversion.

Parameters:

input - the reader to read from

output - the writer to write to

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    java.io.InputStream input,
                                    @Nonnull
                                    java.io.Writer output,
                                    int bufferSize)
                             throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.copy().

Copy and convert bytes from an InputStream to chars on a Writer. The platform's default encoding is used for the byte-to-char conversion.

Parameters:

input - the input stream to read from

output - the writer to write to

bufferSize - size of internal buffer

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    java.io.InputStream input,
                                    @Nonnull
                                    java.io.Writer output,
                                    @Nonnull
                                    java.lang.String encoding)
                             throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.copy().

Copy and convert bytes from an InputStream to chars on a Writer, using the specified encoding.

Parameters:

input - the input stream to read from

output - the writer to write to

encoding - the name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    java.io.InputStream input,
                                    @Nonnull
                                    java.io.Writer output,
                                    @Nonnull
                                    java.lang.String encoding,
                                    int bufferSize)
                             throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.copy().

Copy and convert bytes from an InputStream to chars on a Writer, using the specified encoding.

Parameters:

encoding - the name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.

input - the input stream to read from

output - the writer to write to

bufferSize - size of internal buffer

Throws:

java.io.IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static java.lang.String toString(@Nonnull
                                                              java.io.InputStream input)
                                                       throws java.io.IOException

Deprecated. always specify a character encoding

Get the contents of an InputStream as a String. The platform's default encoding is used for the byte-to-char conversion.

Parameters:

input - the InputStream to read from

Returns:

the resulting string

Throws:

java.io.IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static java.lang.String toString(@Nonnull
                                                              java.io.InputStream input,
                                                              int bufferSize)
                                                       throws java.io.IOException

Deprecated. always specify a character encoding

Get the contents of an InputStream as a String. The platform's default encoding is used for the byte-to-char conversion.

Parameters:

input - the InputStream to read from

bufferSize - size of internal buffer

Returns:

the resulting string

Throws:

java.io.IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static java.lang.String toString(@Nonnull
                                                              java.io.InputStream input,
                                                              @Nonnull
                                                              java.lang.String encoding)
                                                       throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.toString().

Get the contents of an InputStream as a String.

Parameters:

input - the InputStream to read from

encoding - the name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.

Returns:

the converted string

Throws:

java.io.IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static java.lang.String toString(@Nonnull
                                                              java.io.InputStream input,
                                                              @Nonnull
                                                              java.lang.String encoding,
                                                              int bufferSize)
                                                       throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.toString().

Get the contents of an InputStream as a String.

Parameters:

input - the InputStream to read from

encoding - the name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.

bufferSize - size of internal buffer

Returns:

The converted string.

Throws:

java.io.IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       java.io.InputStream input)
                                                throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.readFully().

Get the contents of an InputStream as a byte[].

Parameters:

input - the InputStream to read from

Returns:

the resulting byte array.

Throws:

java.io.IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       java.io.InputStream input,
                                                       int bufferSize)
                                                throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.readFully().

Get the contents of an InputStream as a byte[].

Parameters:

input - the InputStream to read from

bufferSize - size of internal buffer

Returns:

the resulting byte array.

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    java.io.Reader input,
                                    @Nonnull
                                    java.io.OutputStream output)
                             throws java.io.IOException

Deprecated. always specify a character encoding

Serialize chars from a Reader to bytes on an OutputStream, and flush the OutputStream.

Parameters:

input - the InputStream to read from

output - the output stream to write to

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    java.io.Reader input,
                                    @Nonnull
                                    java.io.OutputStream output,
                                    int bufferSize)
                             throws java.io.IOException

Deprecated. always specify a character encoding

Serialize chars from a Reader to bytes on an OutputStream, and flush the OutputStream.

Parameters:

input - the InputStream to read from

output - the output to write to

bufferSize - size of internal buffer

Throws:

java.io.IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static java.lang.String toString(@Nonnull
                                                              java.io.Reader input)
                                                       throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.toString().

Get the contents of a Reader as a String.

Parameters:

input - the InputStream to read from

Returns:

The converted string.

Throws:

java.io.IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static java.lang.String toString(@Nonnull
                                                              java.io.Reader input,
                                                              int bufferSize)
                                                       throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.toString().

Get the contents of a Reader as a String.

Parameters:

input - the reader to read from

bufferSize - size of internal buffer

Returns:

the resulting byte array.

Throws:

java.io.IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       java.io.Reader input)
                                                throws java.io.IOException

Deprecated. always specify a character encoding

Get the contents of a Reader as a byte[].

Parameters:

input - the InputStream to read from

Returns:

the resulting byte array.

Throws:

java.io.IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       java.io.Reader input,
                                                       int bufferSize)
                                                throws java.io.IOException

Deprecated. always specify a character encoding

Get the contents of a Reader as a byte[].

Parameters:

input - the InputStream to read from

bufferSize - size of internal buffer

Returns:

the resulting byte array.

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    java.lang.String input,
                                    @Nonnull
                                    java.io.OutputStream output)
                             throws java.io.IOException

Deprecated. always specify a character encoding

Serialize chars from a String to bytes on an OutputStream, and flush the OutputStream.

Parameters:

input - the InputStream to read from

output - the output to write to

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    java.lang.String input,
                                    @Nonnull
                                    java.io.OutputStream output,
                                    int bufferSize)
                             throws java.io.IOException

Deprecated. always specify a character encoding

Serialize chars from a String to bytes on an OutputStream, and flush the OutputStream.

Parameters:

input - the InputStream to read from

output - the output to write to

bufferSize - size of internal buffer

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    java.lang.String input,
                                    @Nonnull
                                    java.io.Writer output)
                             throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.write().

Copy chars from a String to a Writer.

Parameters:

input - the string to write

output - resulting output Writer

Throws:

java.io.IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       java.lang.String input)
                                                throws java.io.IOException

Deprecated. always specify a character encoding

Get the contents of a String as a byte[].

Parameters:

input - the String to read from

Returns:

the resulting byte array

Throws:

java.io.IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       java.lang.String input,
                                                       int bufferSize)
                                                throws java.io.IOException

Deprecated. always specify a character encoding

Get the contents of a String as a byte[].

Parameters:

input - the InputStream to read from

bufferSize - size of internal buffer

Returns:

the resulting byte array

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    byte[] input,
                                    @Nonnull
                                    java.io.Writer output)
                             throws java.io.IOException

Deprecated. always specify a character encoding

Copy and convert bytes from a byte[] to chars on a Writer. The platform's default encoding is used for the byte-to-char conversion.

Parameters:

input - the InputStream to read from

output - the output to write to

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    byte[] input,
                                    @Nonnull
                                    java.io.Writer output,
                                    int bufferSize)
                             throws java.io.IOException

Deprecated. always specify a character encoding

Copy and convert bytes from a byte[] to chars on a Writer. The platform's default encoding is used for the byte-to-char conversion.

Parameters:

input - the InputStream to read from

output - the output to write to

bufferSize - size of internal buffer

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    byte[] input,
                                    @Nonnull
                                    java.io.Writer output,
                                    java.lang.String encoding)
                             throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.write().

Copy and convert bytes from a byte[] to chars on a Writer, using the specified encoding.

Parameters:

encoding - the name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.

input - the data to write

output - the writer to write to

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    byte[] input,
                                    @Nonnull
                                    java.io.Writer output,
                                    @Nonnull
                                    java.lang.String encoding,
                                    int bufferSize)
                             throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.write().

Copy and convert bytes from a byte[] to chars on a Writer, using the specified encoding.

Parameters:

encoding - the name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.

input - the input bytes

output - The output buffer Writer

bufferSize - size of internal buffer

Throws:

java.io.IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static java.lang.String toString(@Nonnull
                                                              byte[] input)
                                                       throws java.io.IOException

Deprecated. always specify a character encoding

Get the contents of a byte[] as a String. The platform's default encoding is used for the byte-to-char conversion.

Parameters:

input - the input bytes

Returns:

the resulting string

Throws:

java.io.IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static java.lang.String toString(@Nonnull
                                                              byte[] input,
                                                              int bufferSize)
                                                       throws java.io.IOException

Deprecated. always specify a character encoding

Get the contents of a byte[] as a String. The platform's default encoding is used for the byte-to-char conversion.

Parameters:

bufferSize - size of internal buffer

input - the input bytes

Returns:

the created string

Throws:

java.io.IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static java.lang.String toString(@Nonnull
                                                              byte[] input,
                                                              @Nonnull
                                                              java.lang.String encoding)
                                                       throws java.io.IOException

Deprecated. use new String(input, encoding)

Get the contents of a byte[] as a String.

Parameters:

encoding - the name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.

input - the input bytes

Returns:

the resulting string

Throws:

java.io.IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static java.lang.String toString(@Nonnull
                                                              byte[] input,
                                                              @Nonnull
                                                              java.lang.String encoding,
                                                              int bufferSize)
                                                       throws java.io.IOException

Deprecated. use new String(input, encoding)

Get the contents of a byte[] as a String.

Parameters:

encoding - the name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.

bufferSize - size of internal buffer

input - input bytes

Returns:

the resulting string

Throws:

java.io.IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    byte[] input,
                                    @Nonnull
                                    java.io.OutputStream output)
                             throws java.io.IOException

Deprecated. inline this method

Copy bytes from a byte[] to an OutputStream.

Parameters:

input - Input byte array.

output - output stream OutputStream

Throws:

java.io.IOException - in case of failure

contentEquals

@Deprecated
public static boolean contentEquals(@Nonnull
                                                java.io.InputStream input1,
                                                @Nonnull
                                                java.io.InputStream input2)
                                         throws java.io.IOException

Deprecated. use org.apache.commons.io.IOUtils.contentEquals()

Compare the contents of two streams to determine if they are equal or not.

Parameters:

input1 - the first stream

input2 - the second stream

Returns:

true if the content of the streams are equal or they both don't exist, false otherwise

Throws:

java.io.IOException - in case of failure

close

@Deprecated
public static void close(@Nullable
                                     java.nio.channels.Channel channel)

Deprecated. use try-with-resources

Closes a Channel suppressing any IOException.

Note: The use case justifying this method is a shortcoming of the Java language up to but not including Java 7. For any code targeting Java 7 or later use of this method is highly discouraged and the try-with-resources statement should be used instead. Care must be taken to not use this method in a way IOExceptions get suppressed incorrectly. You must close all resources in use inside the try block to not suppress exceptions in the finally block incorrectly by using this method.

Example:

 // Introduce variables for the resources and initialize them to null. This cannot throw an exception.
 Closeable resource1 = null;
 Closeable resource2 = null;
 try
 {
     // Obtain a resource object and assign it to variable resource1. This may throw an exception.
     // If successful, resource1 != null.
     resource1 = ...

     // Obtain a resource object and assign it to variable resource2. This may throw an exception.
     // If successful, resource2 != null. Not reached if an exception has been thrown above.
     resource2 = ...

     // Perform operations on the resources. This may throw an exception. Not reached if an exception has been
     // thrown above. Note: Treat the variables resource1 and resource2 the same way as if they would have been
     // declared with the final modifier - that is - do NOT write anyting like resource1 = something else or
     // resource2 = something else here.
     resource1 ...
     resource2 ...

     // Finally, close the resources and set the variables to null indicating successful completion.
     // This may throw an exception. Not reached if an exception has been thrown above.
     resource1.close();
     resource1 = null;
     // Not reached if an exception has been thrown above.
     resource2.close();
     resource2 = null;

     // All resources are closed at this point and all operations (up to here) completed successfully without
     // throwing an exception we would need to handle (by letting it propagate or by catching and handling it).
 }
 finally
 {
     // Cleanup any resource not closed in the try block due to an exception having been thrown and suppress any
     // exception this may produce to not stop the exception from the try block to be propagated. If the try
     // block completed successfully, all variables will have been set to null there and this will not do
     // anything. This is just to cleanup properly in case of an exception.

     IOUtil.close( resource1 );
     IOUtil.close( resource2 );

     // Without that utility method you would need to write the following:
     //
     // try
     // {
     //     if ( resource1 != null )
     //     {
     //         resource1.close();
     //     }
     // }
     // catch( IOException e )
     // {
     //     Suppressed. If resource1 != null, an exception has already been thrown in the try block we need to
     //     propagate instead of this one.
     // }
     // finally
     // {
     //     try
     //     {
     //         if ( resource2 != null )
     //         {
     //             resource2.close();
     //         }
     //     }
     //     catch ( IOException e )
     //     {
     //         Suppressed. If resource2 != null, an exception has already been thrown in the try block we need to
     //         propagate instead of this one.
     //     }
     // }
 }
 

Parameters:

channel - The channel to close or null.

close

@Deprecated
public static void close(@Nullable
                                     java.io.InputStream inputStream)

Deprecated. use try-with-resources

Closes an InputStream suppressing any IOException.

Note: The use case justifying this method is a shortcoming of the Java language up to but not including Java 7. For any code targeting Java 7 or later use of this method is highly discouraged and the try-with-resources statement should be used instead. Care must be taken to not use this method in a way IOExceptions get suppressed incorrectly. You must close all resources in use inside the try block to not suppress exceptions in the finally block incorrectly by using this method.

Example:

 // Introduce variables for the resources and initialize them to null. This cannot throw an exception.
 Closeable resource1 = null;
 Closeable resource2 = null;
 try
 {
     // Obtain a resource object and assign it to variable resource1. This may throw an exception.
     // If successful, resource1 != null.
     resource1 = ...

     // Obtain a resource object and assign it to variable resource2. This may throw an exception.
     // If successful, resource2 != null. Not reached if an exception has been thrown above.
     resource2 = ...

     // Perform operations on the resources. This may throw an exception. Not reached if an exception has been
     // thrown above. Note: Treat the variables resource1 and resource2 the same way as if they would have been
     // declared with the final modifier - that is - do NOT write anyting like resource1 = something else or
     // resource2 = something else here.
     resource1 ...
     resource2 ...

     // Finally, close the resources and set the variables to null indicating successful completion.
     // This may throw an exception. Not reached if an exception has been thrown above.
     resource1.close();
     resource1 = null;
     // This may throw an exception. Not reached if an exception has been thrown above.
     resource2.close();
     resource2 = null;

     // All resources are closed at this point and all operations (up to here) completed successfully without
     // throwing an exception we would need to handle (by letting it propagate or by catching and handling it).
 }
 finally
 {
     // Cleanup any resource not closed in the try block due to an exception having been thrown and suppress any
     // exception this may produce to not stop the exception from the try block to be propagated. If the try
     // block completed successfully, all variables will have been set to null there and this will not do
     // anything. This is just to cleanup properly in case of an exception.

     IOUtil.close( resource1 );
     IOUtil.close( resource2 );

     // Without that utility method you would need to write the following:
     //
     // try
     // {
     //     if ( resource1 != null )
     //     {
     //         resource1.close();
     //     }
     // }
     // catch( IOException e )
     // {
     //     Suppressed. If resource1 != null, an exception has already been thrown in the try block we need to
     //     propagate instead of this one.
     // }
     // finally
     // {
     //     try
     //     {
     //         if ( resource2 != null )
     //         {
     //             resource2.close();
     //         }
     //     }
     //     catch ( IOException e )
     //     {
     //         Suppressed. If resource2 != null, an exception has already been thrown in the try block we need to
     //         propagate instead of this one.
     //     }
     // }
 }
 

Parameters:

inputStream - The stream to close or null.

close

@Deprecated
public static void close(@Nullable
                                     java.io.OutputStream outputStream)

Deprecated. use try-with-resources

Closes an OutputStream suppressing any IOException.

Note: The use case justifying this method is a shortcoming of the Java language up to but not including Java 7. For any code targeting Java 7 or later use of this method is highly discouraged and the try-with-resources statement should be used instead. Care must be taken to not use this method in a way IOExceptions get suppressed incorrectly. You must close all resources in use inside the try block to not suppress exceptions in the finally block incorrectly by using this method.

Example:

 // Introduce variables for the resources and initialize them to null. This cannot throw an exception.
 Closeable resource1 = null;
 Closeable resource2 = null;
 try
 {
     // Obtain a resource object and assign it to variable resource1. This may throw an exception.
     // If successful, resource1 != null.
     resource1 = ...

     // Obtain a resource object and assign it to variable resource2. This may throw an exception.
     // If successful, resource2 != null. Not reached if an exception has been thrown above.
     resource2 = ...

     // Perform operations on the resources. This may throw an exception. Not reached if an exception has been
     // thrown above. Note: Treat the variables resource1 and resource2 the same way as if they would have been
     // declared with the final modifier - that is - do NOT write anyting like resource1 = something else or
     // resource2 = something else here.
     resource1 ...
     resource2 ...

     // Finally, close the resources and set the variables to null indicating successful completion.
     // This may throw an exception. Not reached if an exception has been thrown above.
     resource1.close();
     resource1 = null;
     // This may throw an exception. Not reached if an exception has been thrown above.
     resource2.close();
     resource2 = null;

     // All resources are closed at this point and all operations (up to here) completed successfully without
     // throwing an exception we would need to handle (by letting it propagate or by catching and handling it).
 }
 finally
 {
     // Cleanup any resource not closed in the try block due to an exception having been thrown and suppress any
     // exception this may produce to not stop the exception from the try block to be propagated. If the try
     // block completed successfully, all variables will have been set to null there and this will not do
     // anything. This is just to cleanup properly in case of an exception.

     IOUtil.close( resource1 );
     IOUtil.close( resource2 );

     // Without that utility method you would need to write the following:
     //
     // try
     // {
     //     if ( resource1 != null )
     //     {
     //         resource1.close();
     //     }
     // }
     // catch( IOException e )
     // {
     //     Suppressed. If resource1 != null, an exception has already been thrown in the try block we need to
     //     propagate instead of this one.
     // }
     // finally
     // {
     //     try
     //     {
     //         if ( resource2 != null )
     //         {
     //             resource2.close();
     //         }
     //     }
     //     catch ( IOException e )
     //     {
     //         Suppressed. If resource2 != null, an exception has already been thrown in the try block we need to
     //         propagate instead of this one.
     //     }
     // }
 }
 

Parameters:

outputStream - The stream to close or null.

close

@Deprecated
public static void close(@Nullable
                                     java.io.Reader reader)

Deprecated. use try-with-resources

Closes a Reader suppressing any IOException.

Note: The use case justifying this method is a shortcoming of the Java language up to but not including Java 7. For any code targeting Java 7 or later use of this method is highly discouraged and the try-with-resources statement should be used instead. Care must be taken to not use this method in a way IOExceptions get suppressed incorrectly. You must close all resources in use inside the try block to not suppress exceptions in the finally block incorrectly by using this method.

Example:

 // Introduce variables for the resources and initialize them to null. This cannot throw an exception.
 Closeable resource1 = null;
 Closeable resource2 = null;
 try
 {
     // Obtain a resource object and assign it to variable resource1. This may throw an exception.
     // If successful, resource1 != null.
     resource1 = ...

     // Obtain a resource object and assign it to variable resource2. This may throw an exception.
     // If successful, resource2 != null. Not reached if an exception has been thrown above.
     resource2 = ...

     // Perform operations on the resources. This may throw an exception. Not reached if an exception has been
     // thrown above. Note: Treat the variables resource1 and resource2 the same way as if they would have been
     // declared with the final modifier - that is - do NOT write anyting like resource1 = something else or
     // resource2 = something else here.
     resource1 ...
     resource2 ...

     // Finally, close the resources and set the variables to null indicating successful completion.
     // This may throw an exception. Not reached if an exception has been thrown above.
     resource1.close();
     resource1 = null;
     // This may throw an exception. Not reached if an exception has been thrown above.
     resource2.close();
     resource2 = null;

     // All resources are closed at this point and all operations (up to here) completed successfully without
     // throwing an exception we would need to handle (by letting it propagate or by catching and handling it).
 }
 finally
 {
     // Cleanup any resource not closed in the try block due to an exception having been thrown and suppress any
     // exception this may produce to not stop the exception from the try block to be propagated. If the try
     // block completed successfully, all variables will have been set to null there and this will not do
     // anything. This is just to cleanup properly in case of an exception.

     IOUtil.close( resource1 );
     IOUtil.close( resource2 );

     // Without that utility method you would need to write the following:
     //
     // try
     // {
     //     if ( resource1 != null )
     //     {
     //         resource1.close();
     //     }
     // }
     // catch( IOException e )
     // {
     //     Suppressed. If resource1 != null, an exception has already been thrown in the try block we need to
     //     propagate instead of this one.
     // }
     // finally
     // {
     //     try
     //     {
     //         if ( resource2 != null )
     //         {
     //             resource2.close();
     //         }
     //     }
     //     catch ( IOException e )
     //     {
     //         Suppressed. If resource2 != null, an exception has already been thrown in the try block we need to
     //         propagate instead of this one.
     //     }
     // }
 }
 

Parameters:

reader - The reader to close or null.

close

@Deprecated
public static void close(@Nullable
                                     java.io.Writer writer)

Deprecated. use try-with-resources

Closes a Writer suppressing any IOException.

Note: The use case justifying this method is a shortcoming of the Java language up to but not including Java 7. For any code targeting Java 7 or later use of this method is highly discouraged and the try-with-resources statement should be used instead. Care must be taken to not use this method in a way IOExceptions get suppressed incorrectly. You must close all resources in use inside the try block to not suppress exceptions in the finally block incorrectly by using this method.

Example:

 // Introduce variables for the resources and initialize them to null. This cannot throw an exception.
 Closeable resource1 = null;
 Closeable resource2 = null;
 try
 {
     // Obtain a resource object and assign it to variable resource1. This may throw an exception.
     // If successful, resource1 != null.
     resource1 = ...

     // Obtain a resource object and assign it to variable resource2. This may throw an exception.
     // If successful, resource2 != null. Not reached if an exception has been thrown above.
     resource2 = ...

     // Perform operations on the resources. This may throw an exception. Not reached if an exception has been
     // thrown above. Note: Treat the variables resource1 and resource2 the same way as if they would have been
     // declared with the final modifier - that is - do NOT write anyting like resource1 = something else or
     // resource2 = something else here.
     resource1 ...
     resource2 ...

     // Finally, close the resources and set the variables to null indicating successful completion.
     // This may throw an exception. Not reached if an exception has been thrown above.
     resource1.close();
     resource1 = null;
     // This may throw an exception. Not reached if an exception has been thrown above.
     resource2.close();
     resource2 = null;

     // All resources are closed at this point and all operations (up to here) completed successfully without
     // throwing an exception we would need to handle (by letting it propagate or by catching and handling it).
 }
 finally
 {
     // Cleanup any resource not closed in the try block due to an exception having been thrown and suppress any
     // exception this may produce to not stop the exception from the try block to be propagated. If the try
     // block completed successfully, all variables will have been set to null there and this will not do
     // anything. This is just to cleanup properly in case of an exception.

     IOUtil.close( resource1 );
     IOUtil.close( resource2 );

     // Without that utility method you would need to write the following:
     //
     // try
     // {
     //     if ( resource1 != null )
     //     {
     //         resource1.close();
     //     }
     // }
     // catch( IOException e )
     // {
     //     Suppressed. If resource1 != null, an exception has already been thrown in the try block we need to
     //     propagate instead of this one.
     // }
     // finally
     // {
     //     try
     //     {
     //         if ( resource2 != null )
     //         {
     //             resource2.close();
     //         }
     //     }
     //     catch ( IOException e )
     //     {
     //         Suppressed. If resource2 != null, an exception has already been thrown in the try block we need to
     //         propagate instead of this one.
     //     }
     // }
 }
 

Parameters:

writer - The writer to close or null.