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ObjectInputStream 和 ObjectOutputStream 介紹_動(dòng)力節(jié)點(diǎn)Java學(xué)院整理

更新時(shí)間：2017年05月12日 10:05:39 投稿：mrr

ObjectInputStream 和 ObjectOutputStream 的作用是，對(duì)基本數(shù)據(jù)和對(duì)象進(jìn)行序列化操作支持。本文給大家詳細(xì)介紹了ObjectInputStream 和 ObjectOutputStream的相關(guān)知識(shí)，感興趣的朋友一起學(xué)習(xí)吧

ObjectInputStream 和 ObjectOutputStream 的作用是，對(duì)基本數(shù)據(jù)和對(duì)象進(jìn)行序列化操作支持。

創(chuàng)建“文件輸出流”對(duì)應(yīng)的ObjectOutputStream對(duì)象，該ObjectOutputStream對(duì)象能提供對(duì)“基本數(shù)據(jù)或?qū)ο蟆钡某志么鎯?chǔ)；當(dāng)我們需要讀取這些存儲(chǔ)的“基本數(shù)據(jù)或?qū)ο蟆睍r(shí)，可以創(chuàng)建“文件輸入流”對(duì)應(yīng)的ObjectInputStream，進(jìn)而讀取出這些“基本數(shù)據(jù)或?qū)ο蟆薄?/p>

注意：只有支持 java.io.Serializable 或 java.io.Externalizable 接口的對(duì)象才能被ObjectInputStream/ObjectOutputStream所操作！

ObjectOutputStream 函數(shù)列表

// 構(gòu)造函數(shù)
ObjectOutputStream(OutputStream output)
// public函數(shù)
void   close()
void   defaultWriteObject()
void   flush()
ObjectOutputStream.PutField   putFields()
void   reset()
void   useProtocolVersion(int version)
void   write(int value)
void   write(byte[] buffer, int offset, int length)
void   writeBoolean(boolean value)
void   writeByte(int value)
void   writeBytes(String value)
void   writeChar(int value)
void   writeChars(String value)
void   writeDouble(double value)
void   writeFields()
void   writeFloat(float value)
void   writeInt(int value)
void   writeLong(long value)
final void   writeObject(Object object)
void   writeShort(int value)
void   writeUTF(String value)
void   writeUnshared(Object object)
ObjectInputStream 函數(shù)列表
// 構(gòu)造函數(shù)
ObjectInputStream(InputStream input)
int   available()
void   close()
void   defaultReadObject()
int   read(byte[] buffer, int offset, int length)
int   read()
boolean   readBoolean()
byte   readByte()
char   readChar()
double   readDouble()
ObjectInputStream.GetField   readFields()
float   readFloat()
void   readFully(byte[] dst)
void   readFully(byte[] dst, int offset, int byteCount)
int   readInt()
String   readLine()
long   readLong()
final Object   readObject()
short   readShort()
String   readUTF()
Object   readUnshared()
int   readUnsignedByte()
int   readUnsignedShort()
synchronized void   registerValidation(ObjectInputValidation object, int priority)
int   skipBytes(int length)

演示程序

源碼如下(ObjectStreamTest.java)：

/**
 * ObjectInputStream 和 ObjectOutputStream 測(cè)試程序
 *
 * 注意：通過ObjectInputStream, ObjectOutputStream操作的對(duì)象，必須是實(shí)現(xiàn)了Serializable或Externalizable序列化接口的類的實(shí)例。
 *
 * 
 */
import java.io.FileInputStream;  
import java.io.FileOutputStream;  
import java.io.ObjectInputStream;  
import java.io.ObjectOutputStream;  
import java.io.Serializable;  
import java.util.Map;
import java.util.HashMap;
import java.util.Iterator;
public class ObjectStreamTest { 
  private static final String TMP_FILE = "box.tmp";
  public static void main(String[] args) {  
    testWrite();
    testRead();
  }
  /**
   * ObjectOutputStream 測(cè)試函數(shù)
   */
  private static void testWrite() {  
    try {
      ObjectOutputStream out = new ObjectOutputStream(
          new FileOutputStream(TMP_FILE));
      out.writeBoolean(true);
      out.writeByte((byte)65);
      out.writeChar('a');
      out.writeInt(20131015);
      out.writeFloat(3.14F);
      out.writeDouble(1.414D);
      // 寫入HashMap對(duì)象
      HashMap map = new HashMap();
      map.put("one", "red");
      map.put("two", "green");
      map.put("three", "blue");
      out.writeObject(map);
      // 寫入自定義的Box對(duì)象，Box實(shí)現(xiàn)了Serializable接口
      Box box = new Box("desk", 80, 48);
      out.writeObject(box);
      out.close();
    } catch (Exception ex) {
      ex.printStackTrace();
    }
  }
  /**
   * ObjectInputStream 測(cè)試函數(shù)
   */
  private static void testRead() {
    try {
      ObjectInputStream in = new ObjectInputStream(
          new FileInputStream(TMP_FILE));
      System.out.printf("boolean:%b\n" , in.readBoolean());
      System.out.printf("byte:%d\n" , (in.readByte()&0xff));
      System.out.printf("char:%c\n" , in.readChar());
      System.out.printf("int:%d\n" , in.readInt());
      System.out.printf("float:%f\n" , in.readFloat());
      System.out.printf("double:%f\n" , in.readDouble());
      // 讀取HashMap對(duì)象
      HashMap map = (HashMap) in.readObject();
      Iterator iter = map.entrySet().iterator();
      while (iter.hasNext()) {
        Map.Entry entry = (Map.Entry)iter.next();
        System.out.printf("%-6s -- %s\n" , entry.getKey(), entry.getValue());
      }
      // 讀取Box對(duì)象，Box實(shí)現(xiàn)了Serializable接口
      Box box = (Box) in.readObject();
      System.out.println("box: " + box);
      in.close();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}
class Box implements Serializable {
  private int width;  
  private int height; 
  private String name;  
  public Box(String name, int width, int height) {
    this.name = name;
    this.width = width;
    this.height = height;
  }
  @Override
  public String toString() {
    return "["+name+": ("+width+", "+height+") ]";
  }
}

運(yùn)行結(jié)果：

boolean:true
byte:65
char:a
int:20131015
float:3.140000
double:1.414000
two  -- green
one  -- red
three -- blue
box: [desk: (80, 48) ]

以上所述是小編給大家介紹的ObjectInputStream 和 ObjectOutputStream 的相關(guān)知識(shí)，希望對(duì)大家有所幫助，如果大家有任何疑問請(qǐng)給我留言，小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)腳本之家網(wǎng)站的支持！

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