InputStreamReader (Java Platform SE 7 ) (original) (raw)

java.lang.Object
- java.io.Reader
- - java.io.InputStreamReader
All Implemented Interfaces:
Closeable, AutoCloseable, Readable
Direct Known Subclasses:
FileReader

public class InputStreamReader
extends Reader
An InputStreamReader is a bridge from byte streams to character streams: It reads bytes and decodes them into characters using a specified charset. The charset that it uses may be specified by name or may be given explicitly, or the platform's default charset may be accepted.
Each invocation of one of an InputStreamReader's read() methods may cause one or more bytes to be read from the underlying byte-input stream. To enable the efficient conversion of bytes to characters, more bytes may be read ahead from the underlying stream than are necessary to satisfy the current read operation.
For top efficiency, consider wrapping an InputStreamReader within a BufferedReader. For example:
BufferedReader in
= new BufferedReader(new InputStreamReader(System.in));

Since:
JDK1.1
See Also:
BufferedReader, InputStream, Charset

Field Summary

 * ### Fields inherited from class java.io.[Reader](../../java/io/Reader.html "class in java.io")  
 `[lock](../../java/io/Reader.html#lock)`

Constructor Summary

Constructors

Constructor and Description
InputStreamReader(InputStream in) Creates an InputStreamReader that uses the default charset.
InputStreamReader(InputStream in,Charset cs) Creates an InputStreamReader that uses the given charset.
InputStreamReader(InputStream in,CharsetDecoder dec) Creates an InputStreamReader that uses the given charset decoder.
InputStreamReader(InputStream in,String charsetName) Creates an InputStreamReader that uses the named charset.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes the stream and releases any system resources associated with it.
String	getEncoding() Returns the name of the character encoding being used by this stream.
int	read() Reads a single character.
int	read(char[] cbuf, int offset, int length) Reads characters into a portion of an array.
boolean	ready() Tells whether this stream is ready to be read.

   * ### Methods inherited from class java.io.[Reader](../../java/io/Reader.html "class in java.io")  
   `[mark](../../java/io/Reader.html#mark%28int%29), [markSupported](../../java/io/Reader.html#markSupported%28%29), [read](../../java/io/Reader.html#read%28char[]%29), [read](../../java/io/Reader.html#read%28java.nio.CharBuffer%29), [reset](../../java/io/Reader.html#reset%28%29), [skip](../../java/io/Reader.html#skip%28long%29)`  
   * ### Methods inherited from class java.lang.[Object](../../java/lang/Object.html "class in java.lang")  
   `[clone](../../java/lang/Object.html#clone%28%29), [equals](../../java/lang/Object.html#equals%28java.lang.Object%29), [finalize](../../java/lang/Object.html#finalize%28%29), [getClass](../../java/lang/Object.html#getClass%28%29), [hashCode](../../java/lang/Object.html#hashCode%28%29), [notify](../../java/lang/Object.html#notify%28%29), [notifyAll](../../java/lang/Object.html#notifyAll%28%29), [toString](../../java/lang/Object.html#toString%28%29), [wait](../../java/lang/Object.html#wait%28%29), [wait](../../java/lang/Object.html#wait%28long%29), [wait](../../java/lang/Object.html#wait%28long,%20int%29)`

Constructor Detail

 * #### InputStreamReader  
 public InputStreamReader([InputStream](../../java/io/InputStream.html "class in java.io") in)  
 Creates an InputStreamReader that uses the default charset.  
 Parameters:  
 `in` \- An InputStream  
 * #### InputStreamReader  
 public InputStreamReader([InputStream](../../java/io/InputStream.html "class in java.io") in,  
                  [String](../../java/lang/String.html "class in java.lang") charsetName)  
                   throws [UnsupportedEncodingException](../../java/io/UnsupportedEncodingException.html "class in java.io")  
 Creates an InputStreamReader that uses the named charset.  
 Parameters:  
 `in` \- An InputStream  
 `charsetName` \- The name of a supported[charset](../../java/nio/charset/Charset.html "class in java.nio.charset")  
 Throws:  
 `[UnsupportedEncodingException](../../java/io/UnsupportedEncodingException.html "class in java.io")` \- If the named charset is not supported  
 * #### InputStreamReader  
 public InputStreamReader([InputStream](../../java/io/InputStream.html "class in java.io") in,  
                  [Charset](../../java/nio/charset/Charset.html "class in java.nio.charset") cs)  
 Creates an InputStreamReader that uses the given charset.  
 Parameters:  
 `in` \- An InputStream  
 `cs` \- A charset  
 Since:  
 1.4  
 * #### InputStreamReader  
 public InputStreamReader([InputStream](../../java/io/InputStream.html "class in java.io") in,  
                  [CharsetDecoder](../../java/nio/charset/CharsetDecoder.html "class in java.nio.charset") dec)  
 Creates an InputStreamReader that uses the given charset decoder.  
 Parameters:  
 `in` \- An InputStream  
 `dec` \- A charset decoder  
 Since:  
 1.4

Method Detail

* #### getEncoding  
public [String](../../java/lang/String.html "class in java.lang") getEncoding()  
Returns the name of the character encoding being used by this stream.  
 If the encoding has an historical name then that name is returned; otherwise the encoding's canonical name is returned.  
 If this instance was created with the [InputStreamReader(InputStream, String)](../../java/io/InputStreamReader.html#InputStreamReader%28java.io.InputStream,%20java.lang.String%29) constructor then the returned name, being unique for the encoding, may differ from the name passed to the constructor. This method will return `null` if the stream has been closed.  
Returns:  
The historical name of this encoding, or`null` if the stream has been closed  
See Also:  
[Charset](../../java/nio/charset/Charset.html "class in java.nio.charset")  
* #### read  
public int read()  
         throws [IOException](../../java/io/IOException.html "class in java.io")  
Reads a single character.  
**Overrides:**  
`[read](../../java/io/Reader.html#read%28%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`  
Returns:  
The character read, or -1 if the end of the stream has been reached  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- If an I/O error occurs  
* #### read  
public int read(char[] cbuf,  
       int offset,  
       int length)  
         throws [IOException](../../java/io/IOException.html "class in java.io")  
Reads characters into a portion of an array.  
**Specified by:**  
`[read](../../java/io/Reader.html#read%28char[],%20int,%20int%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`  
Parameters:  
`cbuf` \- Destination buffer  
`offset` \- Offset at which to start storing characters  
`length` \- 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](../../java/io/IOException.html "class in java.io")` \- If an I/O error occurs  
* #### ready  
public boolean ready()  
              throws [IOException](../../java/io/IOException.html "class in java.io")  
Tells whether this stream is ready to be read. An InputStreamReader is ready if its input buffer is not empty, or if bytes are available to be read from the underlying byte stream.  
**Overrides:**  
`[ready](../../java/io/Reader.html#ready%28%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`  
Returns:  
True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- If an I/O error occurs  
* #### close  
public void close()  
           throws [IOException](../../java/io/IOException.html "class in java.io")  
**Description copied from class: `[Reader](../../java/io/Reader.html#close%28%29)`**  
Closes the stream and releases any system resources associated with it. Once the stream has been closed, further read(), ready(), mark(), reset(), or skip() invocations will throw an IOException. Closing a previously closed stream has no effect.  
**Specified by:**  
`[close](../../java/io/Closeable.html#close%28%29)` in interface `[Closeable](../../java/io/Closeable.html "interface in java.io")`  
**Specified by:**  
`[close](../../java/lang/AutoCloseable.html#close%28%29)` in interface `[AutoCloseable](../../java/lang/AutoCloseable.html "interface in java.lang")`  
**Specified by:**  
`[close](../../java/io/Reader.html#close%28%29)` in class `[Reader](../../java/io/Reader.html "class in java.io")`  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- If an I/O error occurs

Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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InputStreamReader (Java Platform SE 7 ) (original) (raw)

Field Summary

Constructor Summary

Method Summary

Constructor Detail

Method Detail