APIdia Launch Partner
Top Description Fields Constructors Methods
java.io

public Class StringReader

extends Reader
Class Inheritance
Imports
java.util.Objects

A character stream whose source is a string.

API Note

Reader#of(CharSequence) provides a method to read from any CharSequence that may be more efficient than StringReader.

Author
Mark Reinhold
Since
1.1

Field Summary

Modifier and TypeField and Description
private final Reader
r

Inherited from java.io.Reader:
lock

Constructor Summary

AccessConstructor and Description
public
StringReader(String
String providing the character stream.
s
)

Creates a new string reader.

Method Summary

Modifier and TypeMethod and Description
public void
close()

Implements abstract java.io.Reader.close.

Implements java.io.Closeable.close.

Closes the stream and releases any system resources associated with it.

public void
mark(int
Limit on the number of characters that may be read while still preserving the mark. Because the stream's input comes from a string, there is no actual limit, so this argument must not be negative, but is otherwise ignored.
readAheadLimit
)

Overrides java.io.Reader.mark.

Marks the present position in the stream.

public boolean
markSupported()

Overrides java.io.Reader.markSupported.

Tells whether this stream supports the mark() operation, which it does.

public int

Returns:

The character read, or -1 if the end of the stream has been reached
read
()

Overrides java.io.Reader.read.

Reads a single character.

public int
read(char[] cbuf, int off, int len)

Implements abstract java.io.Reader.read.

Reads characters into a portion of an array.

public boolean

Returns:

True if the next read() is guaranteed not to block for input
ready
()

Overrides java.io.Reader.ready.

Tells whether this stream is ready to be read.

public void
reset()

Overrides java.io.Reader.reset.

Resets the stream to the most recent mark, or to the beginning of the string if it has never been marked.

public long
skip(long n)

Overrides java.io.Reader.skip.

Skips characters.

Inherited from java.io.Reader:
nullReaderofreadreadreadAllAsStringreadAllLinestransferTo

Field Detail

rback to summary
private final Reader r

Constructor Detail

StringReaderback to summary
public StringReader(String s)

Creates a new string reader.

Parameters
s:String

String providing the character stream.

Method Detail

closeback to summary
public void close()

Implements abstract java.io.Reader.close.

Implements java.io.Closeable.close.

Closes the stream and releases any system resources associated with it. Once the stream has been closed, further read(), ready(), mark(), or reset() invocations will throw an IOException. Closing a previously closed stream has no effect. This method will block while there is another thread blocking on the reader.

markback to summary
public void mark(int readAheadLimit) throws IOException

Overrides java.io.Reader.mark.

Marks the present position in the stream. Subsequent calls to reset() will reposition the stream to this point.

Parameters
readAheadLimit:int

Limit on the number of characters that may be read while still preserving the mark. Because the stream's input comes from a string, there is no actual limit, so this argument must not be negative, but is otherwise ignored.

Exceptions
IOException:
If an I/O error occurs
IllegalArgumentException:
If readAheadLimit < 0
markSupportedback to summary
public boolean markSupported()

Overrides java.io.Reader.markSupported.

Tells whether this stream supports the mark() operation, which it does.

readback to summary
public int read() throws IOException

Overrides java.io.Reader.read.

Reads a single character.

Returns:int

The character read, or -1 if the end of the stream has been reached

Exceptions
IOException:
If an I/O error occurs
readback to summary
public int read(char[] cbuf, int off, int len) throws IOException

Implements abstract java.io.Reader.read.

Reads characters into a portion of an array.

If len is zero, then no characters are read and 0 is returned; otherwise, there is an attempt to read at least one character. If no character is available because the stream is at its end, the value -1 is returned; otherwise, at least one character is read and stored into cbuf.

Exceptions
IOException:
If an I/O error occurs
IndexOutOfBoundsException:
If off is negative, or len is negative, or len is greater than cbuf.length - off
readyback to summary
public boolean ready() throws IOException

Overrides java.io.Reader.ready.

Tells whether this stream is ready to be read.

Returns:boolean

True if the next read() is guaranteed not to block for input

Exceptions
IOException:
If the stream is closed
resetback to summary
public void reset() throws IOException

Overrides java.io.Reader.reset.

Resets the stream to the most recent mark, or to the beginning of the string if it has never been marked.

Exceptions
IOException:
If an I/O error occurs
skipback to summary
public long skip(long n) throws IOException

Overrides java.io.Reader.skip.

Skips characters. If the stream is already at its end before this method is invoked, then no characters are skipped and zero is returned.

The n parameter may be negative, even though the skip method of the Reader superclass throws an exception in this case. Negative values of n cause the stream to skip backwards. Negative return values indicate a skip backwards. It is not possible to skip backwards past the beginning of the string.

If the entire string has been read or skipped, then this method has no effect and always returns 0.

Exceptions
IOException:
If an I/O error occurs