Applet 和 Servlet 的区别
先决条件: Servlet 和 Applet
Applets | Servlets |
---|---|
A Java applet is a small application which is written in Java and delivered to users in the form of bytecode. | A servlet is a Java programming language class used to extend the capabilities of a server. |
Applets are executed on client side. | Servlets are executed on server side. |
Applets are used to provide interactive features to web applications that cannot be provided by HTML alone like capture mouse input etc. | Servlets are the Java counterpart to other dynamic Web content technologies such as PHP and ASP.NET. |
Life cycle of Applets init(), stop(), paint(), start(), destroy(). | Lifecycle of servlets are:- init( ), service( ), and destroy( ). |
Packages available in Applets are :- import java.applet.*; and import java.awt.*. | Packages available in servlets are:- import javax.servlet.*; and import java.servlet.http.*; |
Applets use user interface classes like AWT and Swing. | No User interface required. |
Applets are more prone to risk as it is on the client machine. | Servlets are under the server security. |
Applets utilize more network bandwidth as it executes on the client machine. | Servlets are executed on the servers and hence require less bandwidth. |
Requires java compatible browser for execution. | It accepts input from browser and generates response in the form of HTML Page, Javascript Object, Applets etc. |
例子:
- 创建“hello world”小程序。
// A Hello World Applet // Save file as HelloWorld.java import java.applet.Applet; import java.awt.Graphics; // HelloWorld class extends Applet public class HelloWorld extends Applet { // Overriding paint() method @Override public void paint(Graphics g) { g.drawString("Hello World", 20, 20); } }
- 创建“hello world”Servlet。
// Import required java libraries import java.io.*; import javax.servlet.*; import javax.servlet.http.*; // Extend HttpServlet class public class HelloWorld extends HttpServlet { private String message; public void init() throws ServletException { // Do required initialization message = "Hello World"; } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // Set response content type response.setContentType("text/html"); // Actual logic goes here. PrintWriter out = response.getWriter(); out.println("
" + message + "
"); } public void destroy() { // do nothing. } }