IOUtil (Apache Maven Shared Utils 3.3.4 API)

java.lang.Object
- org.apache.maven.shared.utils.io.IOUtil

```
public final class IOUtil
extends 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 $Revision$ $Date$

Author:

Peter Donald, Jeff Turner

Method Summary

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

Method Detail

copy

@Deprecated
public static void copy(@Nonnull
                                    InputStream input,
                                    @Nonnull
                                    OutputStream output)
                             throws 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:: IOException - in case of an error

copy

@Deprecated
public static void copy(@Nonnull
                                    InputStream input,
                                    @Nonnull
                                    OutputStream output,
                                    int bufferSize)
                             throws 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:: IOException - in case of an error

copy

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

Deprecated.

Copy chars from a Reader to a Writer.

Parameters:: input - the reader to read from; output - the writer to write to
Throws:: IOException - in case of failure * @deprecated use org.apache.commons.io.IOUtils.copy().

copy

@Deprecated
public static void copy(@Nonnull
                                    Reader input,
                                    @Nonnull
                                    Writer output,
                                    int bufferSize)
                             throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    InputStream input,
                                    @Nonnull
                                    Writer output)
                             throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    InputStream input,
                                    @Nonnull
                                    Writer output,
                                    int bufferSize)
                             throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    InputStream input,
                                    @Nonnull
                                    Writer output,
                                    @Nonnull
                                    String encoding)
                             throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    InputStream input,
                                    @Nonnull
                                    Writer output,
                                    @Nonnull
                                    String encoding,
                                    int bufferSize)
                             throws 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:: IOException - in case of failure

toString
```
@Deprecated
 @Nonnull
public static String toString(@Nonnull
                                                    InputStream input)
                                             throws 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:

IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static String toString(@Nonnull
                                                    InputStream input,
                                                    int bufferSize)
                                             throws 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:: IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static String toString(@Nonnull
                                                    InputStream input,
                                                    @Nonnull
                                                    String encoding)
                                             throws 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:: IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static String toString(@Nonnull
                                                    InputStream input,
                                                    @Nonnull
                                                    String encoding,
                                                    int bufferSize)
                                             throws 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:: IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       InputStream input)
                                                throws 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:: IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       InputStream input,
                                                       int bufferSize)
                                                throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    Reader input,
                                    @Nonnull
                                    OutputStream output)
                             throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    Reader input,
                                    @Nonnull
                                    OutputStream output,
                                    int bufferSize)
                             throws 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:: IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static String toString(@Nonnull
                                                    Reader input)
                                             throws 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:: IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static String toString(@Nonnull
                                                    Reader input,
                                                    int bufferSize)
                                             throws 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:: IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       Reader input)
                                                throws 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:: IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       Reader input,
                                                       int bufferSize)
                                                throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    String input,
                                    @Nonnull
                                    OutputStream output)
                             throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    String input,
                                    @Nonnull
                                    OutputStream output,
                                    int bufferSize)
                             throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    String input,
                                    @Nonnull
                                    Writer output)
                             throws 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:: IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       String input)
                                                throws 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:: IOException - in case of failure

toByteArray

@Deprecated
 @Nonnull
public static byte[] toByteArray(@Nonnull
                                                       String input,
                                                       int bufferSize)
                                                throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    byte[] input,
                                    @Nonnull
                                    Writer output)
                             throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    byte[] input,
                                    @Nonnull
                                    Writer output,
                                    int bufferSize)
                             throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    byte[] input,
                                    @Nonnull
                                    Writer output,
                                    String encoding)
                             throws 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:: IOException - in case of failure

copy

@Deprecated
public static void copy(@Nonnull
                                    byte[] input,
                                    @Nonnull
                                    Writer output,
                                    @Nonnull
                                    String encoding,
                                    int bufferSize)
                             throws 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:: IOException - in case of failure

toString
```
@Deprecated
 @Nonnull
public static String toString(@Nonnull
                                                    byte[] input)
                                             throws 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:

IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static String toString(@Nonnull
                                                    byte[] input,
                                                    int bufferSize)
                                             throws 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:: IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static String toString(@Nonnull
                                                    byte[] input,
                                                    @Nonnull
                                                    String encoding)
                                             throws 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:: IOException - in case of failure

toString

@Deprecated
 @Nonnull
public static String toString(@Nonnull
                                                    byte[] input,
                                                    @Nonnull
                                                    String encoding,
                                                    int bufferSize)
                                             throws 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:: IOException - in case of failure

copy

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

Deprecated. inline this method

Copy bytes from a byte[] to an OutputStream.

Parameters:: input - Input byte array.; output - output stream OutputStream
Throws:: IOException - in case of failure

contentEquals

@Deprecated
public static boolean contentEquals(@Nonnull
                                                InputStream input1,
                                                @Nonnull
                                                InputStream input2)
                                         throws 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:: IOException - in case of failure

close

@Deprecated
public static void close(@Nullable
                                     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
                                     InputStream inputStream)

Deprecated. use try-with-resources

Closes an InputStream suppressing any IOException.

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
                                     OutputStream outputStream)

Deprecated. use try-with-resources

Closes an OutputStream suppressing any IOException.

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
                                     Reader reader)

Deprecated. use try-with-resources

Closes a Reader suppressing any IOException.

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
                                     Writer writer)

Deprecated. use try-with-resources

Closes a Writer suppressing any IOException.

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.

Class IOUtil

Method Summary

Methods inherited from class java.lang.Object

Method Detail

copy

copy

copy

copy

copy

copy

copy

copy

toString

toString

toString

toString

toByteArray

toByteArray

copy

copy

toString

toString

toByteArray

toByteArray

copy

copy

copy

toByteArray

toByteArray

copy

copy

copy

copy

toString

toString

toString

toString

copy

contentEquals

close

close

close

close

close