分类:
2008-09-12 09:14:10
第一步,编写需要传递的对象类
/**
* Class Person just a demo for translate this class to client
* @author: rookie
* @datetime: 2002-7-26
*/
package exapplet;
import java.io.*;
public class Person implements Serializable {//必须实现Serializable接口才能序列化
private String m_Name;
private int m_Age;
public Person() {
this("",0);
}
public Person(String name,int age) {
this.m_Name = name;
this.m_Age = age;
}
public String getName() {
return m_Name;
}
public int getAge() {
return m_Age;
}
//Serializable接口中声明的方法
private void writeObject(java.io.ObjectOutputStream out)
throws IOException {
out.defaultWriteObject();
}
//Serializable接口中声明的方法
private void readObject(java.io.ObjectInputStream in)
throws IOException, ClassNotFoundException {
in.defaultReadObject();
}
public static void main(String[] args) {
try {
Person p = new Person("Liaoyuan",25);
ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(new File("test.obj")));
oos.writeObject(p);
oos.close();
ObjectInputStream ois = new ObjectInputStream (new FileInputStream(new File("test.obj")));
Person q = (Person)ois.readObject();
ois.close();
System.out.println(q.getName());
System.out.println(q.getAge());
} catch(Exception exp) {
exp.printStackTrace();
}
}
}
第二步,实现Servlet
package exapplet;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class MyServlet extends HttpServlet
{
public void doGet(HttpServletRequest req,HttpServletResponse res)
throws ServletException,IOException
{
String fPath = "H:\\XSchool\\WorkingRoom\\exapplet\\src\\java.obj";
String act = req.getParameter("Action");
if ( act.equals("UpdateObject") ) {
//创建更新JavaObject
Person p = new Person("Liaoyuan",26);
ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(new File(fPath)));
oos.writeObject(p);
oos.close();
DataOutputStream dos = new DataOutputStream(res.getOutputStream());
dos.writeBytes("Server Java Object Updated OK!");
dos.close();
} else if ( act.equals("GetObject") ) {
//传回对象给Applet
res.setContentType("application/octet-stream");
Person p;
ObjectInputStream ois = new ObjectInputStream(new FileInputStream(new File(fPath)));
try {
p = (Person)ois.readObject();
} catch (ClassNotFoundException e) {
p = new Person();
}
ois.close();
ObjectOutputStream oos = new ObjectOutputStream(res.getOutputStream());
oos.writeObject(p);
oos.close();
}
}
public String getServletInfo()
{
return "A simple Servlet!";
}
}
第三步,实现呼叫Servlet更新对象的Applet
package exapplet;
import java.awt.*;
import java.applet.*;
import java.io.*;
import java.net.*;
import netscape.javascript.*;
public class MyApplet extends java.applet.Applet
{
public void init()
{
}
public void paint(Graphics g)
{}
//This method will be call in html
public void invoke() {
try {
URL url = new URL("");
URLConnection urlcon = url.openConnection();
urlcon.connect();
DataInputStream dis=new DataInputStream(urlcon.getInputStream());
String txt = dis.readLine();
dis.close();
String[] info = new String[]{txt};
JSObject.getWindow(this).call("alert",info);
} catch (Exception e) {
}
}
}
第四步,实现提取对象的Applet
package exapplet;
import java.awt.*;
import java.applet.*;
import java.io.*;
import java.net.*;
import netscape.javascript.*;
public class MyAppletB extends java.applet.Applet
{
public void init()
{
}
public void paint(Graphics g)
{}
//This method will be call in html
public void invoke() {
try {
URL url = new URL("");
URLConnection urlcon = url.openConnection();
urlcon.connect();
ObjectInputStream ois=new ObjectInputStream(urlcon.getInputStream());
Person p = (Person)ois.readObject();
ois.close();
String[] info = new String[]{"Person Info\n\n-Name: "+p.getName()+"\n-Age : "+p.getAge()};
JSObject.getWindow(this).call("alert",info);
} catch (Exception e) {
}
}
}
第五步,配制WebServer(我用的是Tomcat4.0)
拷贝编译后的MyServlet.class到相应目录下,
编辑对应的web.xml文件,确保下面的内容正确
PostToApplet
exapplet.MyServlet
PostToApplet
/exapplet/PostToApplet
第六步,编写html文件
呼叫更新的html
New Document For Using Applet Call Servlet Update Java Object
Hello This is a Test!
提取对象的html
New Document For Using Applet
Hello This is a Test!