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.
- Since:
- 1.1
Field Summary
Fields declared in class java.io.Reader
lock
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 ns) | Skips the specified number of characters in the stream. |
Methods declared in class java.io.Reader
nullReader, read, read, transferTo
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Constructor Detail
StringReader
public StringReader(String s)
Creates a new string reader.
- Parameters:
-
s
- String providing the character stream.
Method Detail
read
public int read() throws IOException
Reads a single character.
- Overrides:
-
read
in classReader
- 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.
- Specified by:
-
read
in classReader
- Parameters:
-
cbuf
- Destination buffer -
off
- Offset at which to start writing 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:
-
IOException
- If an I/O error occurs -
IndexOutOfBoundsException
- If an I/O error occurs
skip
public long skip(long ns) throws IOException
Skips the specified number of characters in the stream. Returns the number of characters that were skipped.
The ns
parameter may be negative, even though the skip
method of the Reader
superclass throws an exception in this case. Negative values of ns
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 classReader
- Parameters:
-
ns
- 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 classReader
- 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 classReader
- 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 classReader
- 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
- IfreadAheadLimit < 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 classReader
- 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.