com.github.robtimus.io.stream

Class CapturingReader

java.lang.Object

java.io.Reader

com.github.robtimus.io.stream.CapturingReader

All Implemented Interfaces:

Closeable, AutoCloseable, Readable

public final class CapturingReader
extends Reader

A reader that captures the content it reads. This can be useful for readers that are handed over to other code, where it is unknown when the reader is consumed. Using callbacks this class allows code to be executed when the stream has been fully consumed.

An example use for this class can be logging in an HTTP filter or HTTP client. Instead of copying the contents of a reader to memory, logging the contents, and then passing a StringReader with the copied contents, you can create a capturing reader with a callback that performs the logging.

CapturingReader supports mark(int) and reset() if its backing reader does. When reset() is called, it will "uncapture" any contents up to the previous mark. It will still only once call any of the callbacks.

Author:

Rob Spoor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CapturingReader.Config Configuration for capturing readers.

Field Summary

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Constructor and Description
CapturingReader(Reader input, CapturingReader.Config config) Creates a new capturing reader.

Method Summary

Modifier and Type	Method and Description
String	captured() Returns the contents that have been captured.
void	close()
static CapturingReader.Config.Builder	config() Creates a builder for capturing reader configurations.
boolean	isClosed() Returns whether or not this reader has been closed.
boolean	isConsumed() Returns whether or not this reader has been fully consumed.
void	mark(int readlimit)
boolean	markSupported()
int	read()
int	read(char[] c)
int	read(char[] c, int off, int len)
void	reset()
long	totalChars() Returns the total number of characters that have been read.

Methods inherited from class java.io.Reader

read, ready, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

CapturingReader

public CapturingReader(Reader input,
                       CapturingReader.Config config)

Creates a new capturing reader.

Parameters:

input - The reader to capture from.

config - The configuration to use.

Throws:

NullPointerException - If the given reader or config is null.

Method Detail

read

public int read()
         throws IOException

Overrides:

read in class Reader

Throws:

IOException

read

public int read(char[] c)
         throws IOException

Overrides:

read in class Reader

Throws:

IOException

read

public int read(char[] c,
                int off,
                int len)
         throws IOException

Specified by:

read in class Reader

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in class Reader

Throws:

IOException

mark

public void mark(int readlimit)
          throws IOException

Overrides:

mark in class Reader

Throws:

IOException

reset

public void reset()
           throws IOException

Overrides:

reset in class Reader

Throws:

IOException

markSupported

public boolean markSupported()

Overrides:

markSupported in class Reader

captured

public String captured()

Returns the contents that have been captured.

Returns:

A string representing the contents that have been captured.

totalChars

public long totalChars()

Returns the total number of characters that have been read.

Returns:

The total number of characters that have been read.

isConsumed

public boolean isConsumed()

Returns whether or not this reader has been fully consumed. In other words, returns whether or not one of the read methods has been called and returned -1.

Returns:

true if this reader has been fully consumed, or false otherwise.

isClosed

public boolean isClosed()

Returns whether or not this reader has been closed.

Returns:

true if this reader has been closed, or false otherwise.

config

public static CapturingReader.Config.Builder config()

Creates a builder for capturing reader configurations.

Returns:

The created builder.