Class StringReader

java.lang.Object

java.io.Reader

java.io.StringReader

All Implemented Interfaces:: Closeable, AutoCloseable, Readable

public class StringReader extends Reader

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.
Since:: 1.1

Field Summary

Fields declared in class Reader

lock

Modifier and Type	Field	Description
`protected Object`	`lock`	The object used to synchronize operations on this stream.

Constructor Summary

Constructor	Description
`StringReader(String s)`	Creates a new string reader.

Method Summary

Modifier and Type	Method	Description
`void`	`close()`	Closes the stream and releases any system resources associated with it.
`void`	`mark(int readAheadLimit)`	Marks the present position in the stream.
`boolean`	`markSupported()`	Tells whether this stream supports the mark() operation, which it does.
`int`	`read()`	Reads a single character.
`int`	`read(char[] cbuf, int off, int len)`	Reads characters into a portion of an array.
`boolean`	`ready()`	Tells whether this stream is ready to be read.
`void`	`reset()`	Resets the stream to the most recent mark, or to the beginning of the string if it has never been marked.
`long`	`skip(long n)`	Skips characters.

Methods declared in class Reader

nullReader, of, read, read, readAllAsString, readAllLines, transferTo

Modifier and Type	Method	Description
`static Reader`	`nullReader()`	Returns a new `Reader` that reads no characters.
`static Reader`	`of(CharSequence cs)`	Returns a `Reader` that reads characters from a `CharSequence`.
`int`	`read(char[] cbuf)`	Reads characters into an array.
`int`	`read(CharBuffer target)`	Attempts to read characters into the specified character buffer.
`String`	`readAllAsString()`	Reads all remaining characters into a string.
`List<String>`	`readAllLines()`	Reads all remaining characters as lines of text.
`long`	`transferTo(Writer out)`	Reads all characters from this reader and writes the characters to the given writer in the order that they are read.

Methods declared in class Object

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

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Constructor Details

StringReader

public StringReader(String s)

Creates a new string reader.

Parameters:: s - String providing the character stream.

Method Details

read

public int read() throws IOException

Reads a single character.

Overrides:: read in class Reader
Returns:: The character read, or -1 if the end of the stream has been reached
Throws:: IOException - If an I/O error occurs

read

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

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.

Specified by:: read in class Reader
Parameters:: cbuf - Destination buffer; off - Offset at which to start storing characters; len - Maximum number of characters to read
Returns:: The number of characters read, or -1 if the end of the stream has been reached
Throws:: IndexOutOfBoundsException - If off is negative, or len is negative, or len is greater than cbuf.length - off; IOException - If an I/O error occurs

skip

public long skip(long n) throws IOException

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.

Overrides:: skip in class Reader
Parameters:: n - The number of characters to skip
Returns:: The number of characters actually skipped
Throws:: IOException - If an I/O error occurs

ready

public boolean ready() throws IOException

Tells whether this stream is ready to be read.

Overrides:: ready in class Reader
Returns:: True if the next read() is guaranteed not to block for input
Throws:: IOException - If the stream is closed

markSupported

public boolean markSupported()

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

Overrides:: markSupported in class Reader
Returns:: true if and only if this stream supports the mark operation.

mark

public void mark(int readAheadLimit) throws IOException

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

Overrides:: mark in class Reader
Parameters:: readAheadLimit - 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.
Throws:: IllegalArgumentException - If readAheadLimit < 0; IOException - If an I/O error occurs

reset

public void reset() throws IOException

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

Overrides:: reset in class Reader
Throws:: IOException - If an I/O error occurs

close

public void 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.

Specified by:: close in interface AutoCloseable
Specified by:: close in interface Closeable
Specified by:: close in class Reader

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