DataOutputStream

DataOutputStream

java.io

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Java 1.0

closeable flushable

This class is a subclass of FilterOutputStream that allows you to write Java primitive data types in a portable binary format. Create a DataOutputStream by specifying the OutputStream that is to be filtered in the call to the constructor. DataOutputStream has methods that output only primitive types; use ObjectOutputStream to output object values.

Many of this class's methods write a single Java primitive type, in binary format, to the output stream. write( ) writes a single byte, an array, or a subarray of bytes. flush( ) forces any buffered data to be output. size ( ) returns the number of bytes written so far. writeUTF( ) outputs a Java string of Unicode characters using 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. Except for the writeUTF( ) method, this class is used for binary output of data. Textual output should be done with PrintWriter (or PrintStream in Java 1.0).

Figure 9-11. java.io.DataOutputStream

 public class  DataOutputStream  extends FilterOutputStream implements DataOutput {  // Public Constructors  public  DataOutputStream  (OutputStream  out  );  // Public Instance Methods  public final int  size  ( );  // Methods Implementing DataOutput  public void  write  (int  b  ) throws IOException;  synchronized  public void  write  (byte[ ]  b  , int  off  , int  len  ) throws IOException;  synchronized  public final void  writeBoolean  (boolean  v  ) throws IOException;        public final void  writeByte  (int  v  ) throws IOException;        public final void  writeBytes  (String  s  ) throws IOException;        public final void  writeChar  (int  v  ) throws IOException;        public final void  writeChars  (String  s  ) throws IOException;        public final void  writeDouble  (double  v  ) throws IOException;        public final void  writeFloat  (float  v  ) throws IOException;        public final void  writeInt  (int  v  ) throws IOException;        public final void  writeLong  (long  v  ) throws IOException;        public final void  writeShort  (int  v  ) throws IOException;        public final void  writeUTF  (String  str  ) throws IOException;  // Public Methods Overriding FilterOutputStream  public void  flush  ( ) throws IOException;  // Protected Instance Fields  protected int  written  ;   }