- Java.io package classes
- Java.io - Home
- Java.io - BufferedInputStream
- Java.io - BufferedOutputStream
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- 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.FileInputStream.read() Method
Description
The java.io.FileInputStream.read(byte[] b) reads upto the b.length from this file input stream to the array of bytes. The method blocks until some input is available.
Declaration
Following is the declaration for java.io.FileInputStream.read(byte[] b) method −
public int read(byte[] b)
Parameters
b − The byte array into which data is read.
Return Value
The methods returns the total number of bytes read into the buffer, or -1 if there is no more data to be read.
Exception
IOException − If an I/O error occurs.
Example
The following example shows the usage of java.io.FileInputStream.read(byte[] b) method.
package com.tutorialspoint; import java.io.IOException; import java.io.FileInputStream; public class FileInputStreamDemo { public static void main(String[] args) throws IOException { FileInputStream fis = null; int i = 0; char c; byte[] bs = new byte[4]; try { // create new file input stream fis = new FileInputStream("C://test.txt"); // read bytes to the buffer i = fis.read(bs); // prints System.out.println("Number of bytes read: "+i); System.out.print("Bytes read: "); // for each byte in buffer for(byte b:bs) { // converts byte to character c = (char)b; // print System.out.print(c); } } catch(Exception ex) { // if any error occurs ex.printStackTrace(); } finally { // releases all system resources from the streams if(fis!=null) fis.close(); } } }
Assuming we have a text file c:/test.txt, which has the following content. This file will be used as an input for our example program −
ABCDEF
Let us compile and run the above program, this will produce the following result −
Number of bytes read: 4 Bytes read: ABCD
java_io_fileinputstream.htm
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