Question

我有一个applet，我必须向Web应用程序发送请求，以从数据库中的服务器获取数据。我正在使用对象，服务器响应对象非常有用!!

小程序如何与服务器通信？

我认为网络服务方法，RMI和...让我开心，但哪个最好又可靠？

Answer 1

只要您的applet与服务器通信，您就可以使用序列化对象。您只需要在applet jar和服务器上维护相同版本的对象类。它不是最开放或可扩展的方式，但它在开发时间和相当稳固方面很快。

这是一个例子。

实例化与servlet的连接

URL servletURL = new URL("<URL To your Servlet>");
URLConnection servletConnect = servletURL.openConnection();
servletConnect.setDoOutput(true); // to allow us to write to the URL
servletConnect.setUseCaches(false); // Write the message to the servlet and not from the browser's cache
servletConnect.setRequestProperty("Content-Type","application/x-java-serialized-object");

获取输出流并编写对象

MyCustomObject myObject = new MyCustomObject()
ObjectOutputStream outputToServlet;
outputToServlet = new ObjectOutputStream(servletConnection.getOutputStream());
outputToServlet.writeObject(myObject);
outputToServlet.flush(); //Cleanup
outputToServlet.close();

现在阅读回复

ObjectInputStream in = new ObjectInputStream(servletConnection.getInputStream());
MyRespObject myrespObj;
try
{
    myrespObj= (MyRespObject) in.readObject();
} catch (ClassNotFoundException e1)
{
    e1.printStackTrace();
}

in.close();

在你的servlet中

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
  MyRespObject myrespObj= processSomething(request);
  response.reset();
  response.setHeader("Content-Type", "application/x-java-serialized-object");
  ObjectOutputStream outputToApplet;
  outputToApplet = new ObjectOutputStream(response.getOutputStream());
  outputToApplet.writeObject(myrespObj);
  outputToApplet.flush();
  outputToApplet.close();
}

private MyRespObject processSomething(HttpServletRequest request)
{
  ObjectInputStream inputFromApplet = new ObjectInputStream(request.getInputStream());
  MyCustomObject myObject = (MyCustomObject) inputFromApplet.readObject();
  //Do Something with the object you just passed
  MyRespObject myrespObj= new MyRespObject();
  return myrespObj;
}

请记住，您传递的两个对象都需要实现可序列化的

 public Class MyCustomObject implements java.io.Serializable
 {

Applet - 服务器通信，我该怎么办？

1 个答案: