- Java.io package classes
- Java.io - Home
- Java.io - BufferedInputStream
- Java.io - BufferedOutputStream
- Java.io - BufferedReader
- Java.io - BufferedWriter
- Java.io - ByteArrayInputStream
- Java.io - ByteArrayOutputStream
- Java.io - CharArrayReader
- Java.io - CharArrayWriter
- Java.io - Console
- Java.io - DataInputStream
- Java.io - DataOutputStream
- Java.io - File
- Java.io - FileDescriptor
- Java.io - FileInputStream
- Java.io - FileOutputStream
- Java.io - FilePermission
- Java.io - FileReader
- Java.io - FileWriter
- Java.io - FilterInputStream
- Java.io - FilterOutputStream
- Java.io - FilterReader
- Java.io - FilterWriter
- Java.io - InputStream
- Java.io - InputStreamReader
- Java.io - LineNumberInputStream
- Java.io - LineNumberReader
- Java.io - ObjectInputStream
- Java.io - ObjectInputStream.GetField
- Java.io - ObjectOutputStream
- io - ObjectOutputStream.PutField
- Java.io - ObjectStreamClass
- Java.io - ObjectStreamField
- Java.io - OutputStream
- Java.io - OutputStreamWriter
- Java.io - PipedInputStream
- Java.io - PipedOutputStream
- Java.io - PipedReader
- Java.io - PipedWriter
- Java.io - PrintStream
- Java.io - PrintWriter
- Java.io - PushbackInputStream
- Java.io - PushbackReader
- Java.io - RandomAccessFile
- Java.io - Reader
- Java.io - SequenceInputStream
- Java.io - SerializablePermission
- Java.io - StreamTokenizer
- Java.io - StringBufferInputStream
- Java.io - StringReader
- Java.io - StringWriter
- Java.io - Writer
- Java.io package extras
- Java.io - Interfaces
- Java.io - Exceptions
- Java.io package Useful Resources
- Java.io - Discussion
Java.io.Reader.read() Method
Description
The java.io.Reader.read(CharBuffer target) method attempts to read characters into the specified character buffer. The buffer is used as a repository of characters as-is: the only changes made are the results of a put operation. No flipping or rewinding of the buffer is performed.
Declaration
Following is the declaration for java.io.Reader.read() method.
public int read(CharBuffer target)
Parameters
target − The buffer to read characters into.
Return Value
This method returns the number of characters added to the buffer, or -1 if this source of characters is at its end.
Exception
IOException − If the stream does not support mark(), or if some other I/O error occurs.
NullPointerException − If target is null.
ReadOnlyBufferException − If target is a read only buffer.
Example
The following example shows the usage of java.io.Reader.read() method.
package com.tutorialspoint; import java.io.*; import java.nio.CharBuffer; public class ReaderDemo { public static void main(String[] args) { String s = "Hello world"; // create a new Char Buffer with capacity of 12 CharBuffer cb = CharBuffer.allocate(12); // create a StringReader Reader reader = new StringReader(s); try { // read characters into a char buffer reader.read(cb); // flip the char buffer cb.flip(); // print the char buffer System.out.println(cb.toString()); // Close the stream reader.close(); } catch (IOException ex) { ex.printStackTrace(); } } }
Let us compile and run the above program, this will produce the following result −
Hello world