Java.io.ObjectOutputStream.writeFields()方法实例

java.io.ObjectOutputStream.writeFields() 方法缓冲字段的数据流。

声明

以下是java.io.ObjectOutputStream.writeFields()方法的声明

public void writeFields()

参数

  • NA

返回值

此方法没有返回值。

异常

  • IOException -- 如果在写入底层流发生I / O错误

  • NotActiveException -- 调用当writeObject类的方法是不调用写对象的状态。

例子

下面的示例演示java.io.ObjectOutputStream.writeFields()方法的用法。

package com.yiibai;import java.io.*;public class ObjectOutputStreamDemo { public static void main(String[] args) { double d = 1.59875d; try { // create a new file with an ObjectOutputStream FileOutputStream out = new FileOutputStream("test.txt"); ObjectOutputStream oout = new ObjectOutputStream(out); // write something in the file oout.writeObject(new Example()); oout.flush(); oout.close(); // create an ObjectInputStream for the file we created before ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt")); // read an object from the stream and cast it to Example Example a = (Example) ois.readObject(); // print var of a System.out.println("" + a.var); } catch (Exception ex) { ex.printStackTrace(); } } static public class Example implements Serializable { static int var = 76458; // assign a new serialPersistentFields  private static final ObjectStreamField[] serialPersistentFields = { new ObjectStreamField("var", Integer.TYPE) }; private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException { // get the field and assign it at var ObjectInputStream.GetField fields = in.readFields(); // get var var = fields.get("var", 0); } private void writeObject(ObjectOutputStream out) throws IOException { // write into the ObjectStreamField array the variable string ObjectOutputStream.PutField fields = out.putFields(); fields.put("var", var); out.writeFields(); } }}

让我们编译和运行上面的程序,这将产生以下结果: