Java.io.ObjectOutputStream.writeFields()方法實例

java.io.ObjectOutputStream.writeFields() 方法緩衝字段的數據流。

聲明

以下是java.io.ObjectOutputStream.writeFields()方法的聲明

public void writeFields()

參數

• NA

返回值

此方法沒有返回值。

異常

• IOException -- 如果在寫入底層流發生I / O錯誤

• NotActiveException -- 調用當writeObject類的方法是不調用寫對象的狀態。

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(); } } }

讓我們編譯和運行上面的程序，這將產生以下結果：

76458