java _io_对象流，能够保存基本数据类型和对象

• ObjectInputStream(字节流) 和ObjectOutputStream(字节流)

• 除了保存基本数据类型，还包括自定义的对象，自定义的对象读取后类型是Object，使用需要强制转换

• 序列化:输出流，

• 反序列化:输入流

• 和数据流一致，必须先写出后读取，读取和写出顺序保持一致

• 序列化的对象必须实现java.io.Serializable接口

• transient:该数据不需要序列化，数据透明(输出显示null),private transient String name;

  //写出后读取，读取的数徐与写出保持一致

   public class n {
  
   public static void main(String[]args) throws IOException, ClassNotFoundException
   {
  

  写入字节数组 //写出 序列化 ByteArrayOutputStream os=new ByteArrayOutputStream(); ObjectOutputStream oos=new ObjectOutputStream(new BufferedOutputStream(os)); ha ff=new ha("hh",222);

   oos.writeUTF("哈哈");
   oos.writeChar('q');
   oos.writeBoolean(false);
  
   oos.writeObject(ff);
   oos.flush();
   byte[] datas=os.toByteArray();
   oos.close();
   //读取 反序列化
   ObjectInputStream ois =new ObjectInputStream(new BufferedInputStream(new ByteArrayInputStream(datas)));
   String s=ois.readUTF();
   char ch=ois.readChar();
   boolean flag=ois.readBoolean();	
   Object str=ois.readObject();  //Object需要强制转换
   
   //还原(判断是哪个类，然后强制转换):
   if (str instanceof String ) //是String类就直接转换成字符串
   {
   	String s1=(String)str;
   	System.out.println(s1);
   }
   if(str instanceof Data)
   {
   	Date d=(Date)str;
   	System.out.println(d);
   }
   if(str instanceof ha)
   {
   	ha fr=(ha)str;
   	System.out.println(fr.getName()+fr.getSalary());
   }
   ois.close();
   }
   
   //javabean，用于封装数据	
   class ha implements java.io.Serializable  {
  
   private transient String name;  //该数据不需要序列化，数据透明
   private double salary;
  
   public ha()
   	{
   
   }
  
   public ha(String name,double salary)
   {
   this.name=name;
   this.salary=salary;
   }
  
   public String getName() {
   return name;
   }
  
   public void setName(String name) {
   this.name = name;
   }
  
   public double getSalary() {
   return salary;
   }
  
   public void setSalary(double salary) {
   this.salary = salary;
   }
  
   }
  

写入文件:

	  ObjectOutputStream oos=new ObjectOutputStream(new  BufferedOutputStream(new FileOutputStream("D:/d/s")));
		ha ff=new ha("hh",222);
		oos.writeUTF("what");
		oos.writeObject(ff);
		oos.flush();
		oos.close();
	
	//使用时，反序列化对象
	
	ObjectInputStream  ois=new ObjectInputStream(new BufferedInputStream(new FileInputStream("D:/d/s")));
	String s=ois.readUTF();
	Object it=ois.readObject();
	
	if(it instanceof ha)
	{
		ha q=(ha)it;
		System.out.println(q.getName()+q.getSalary());
	}
	ois.close();
	
	//javabean 用于封装数据
class ha implements java.io.Serializable  {

private transient String name;  //该数据不需要序列化，数据透明
private double salary;

public ha()
{
	
}

public ha(String name,double salary)
{
	this.name=name;
	this.salary=salary;
}

public String getName() {
	return name;
}

public void setName(String name) {
	this.name = name;
}

public double getSalary() {
	return salary;
}

public void setSalary(double salary) {
	this.salary = salary;
}

}