This class is a type of FilterInputStream that allows you to read binary representations of Java primitive data types in a portable way. Create a DataInputStream by specifying the InputStream that is to be filtered in the call to the constructor. DataInputStream reads only primitive Java types; use ObjectInputStream to read object values.

Many of the methods read and return a single Java primitive type, in binary format, from the stream. readUnsignedByte( ) and readUnsignedShort( ) read unsigned values and return them as int values, since unsigned byte and short types are not supported in Java. read( ) reads data into an array of bytes, blocking until at least some data is available. By contrast, readFully( ) reads data into an array of bytes, but blocks until all requested data becomes available. skipBytes( ) blocks until the specified number of bytes have been read and discarded. readLine( ) reads characters from the stream until it encounters a newline, a carriage return, or a newline/carriage return pair. The returned string is not terminated with a newline or carriage return. This method is deprecated as of Java 1.1; see BufferedReader for an alternative. readUTF( ) reads a string of Unicode text encoded in a slightly modified version of the UTF-8 transformation format. UTF-8 is an ASCII-compatible encoding of Unicode characters that is often used for the transmission and storage of Unicode text. This class uses a modified UTF-8 encoding that never contains embedded null characters.

Figure 9-10. java.io.DataInputStream

public class DataInputStream extends FilterInputStream implements DataInput {
// Public Constructors
     public DataInputStream(InputStream in);  
// Public Class Methods
     public static final String readUTF(DataInput in) throws IOException;  
// Methods Implementing DataInput
     public final boolean readBoolean( ) throws IOException;  
     public final byte readByte( ) throws IOException;  
     public final char readChar( ) throws IOException;  
     public final double readDouble( ) throws IOException;  
     public final float readFloat( ) throws IOException;  
     public final void readFully(byte[ ] b) throws IOException;  
     public final void readFully(byte[ ] b, int off, int len) throws IOException;  
     public final int readInt( ) throws IOException;  
     public final long readLong( ) throws IOException;  
     public final short readShort( ) throws IOException;  
     public final int readUnsignedByte( ) throws IOException;  
     public final int readUnsignedShort( ) throws IOException;  
     public final String readUTF( ) throws IOException;  
     public final int skipBytes(int n) throws IOException;  
// Public Methods Overriding FilterInputStream
     public final int read(byte[ ] b) throws IOException;  
     public final int read(byte[ ] b, int off, int len) throws IOException;  
// Deprecated Public Methods
#    public final String readLine( ) throws IOException;                Implements:DataInput
}