Servlet简单实现

朴灿烈づ我的快乐病毒、 2022-05-21 06:29 175阅读 0赞

1. 编写servlet源文件  
在src目录下新建HelloWorld.java，并编写一下代码并进行编译：

1.  import javax.servlet.ServletException;
2.  import javax.servlet.http.HttpServlet;
3.  import javax.servlet.http.HttpServletRequest;
4.  import javax.servlet.http.HttpServletResponse;
5.  import java.io.IOException;
6.  import java.io.PrintWriter;
7.  
8.  public class HelloWorld extends HttpServlet\{
9.  private String message;
10. 
11. @Override
12. public void init() throws ServletException \{
13. message = "Hello world, this message is from servlet!";
14. \}
15. 
16. @Override
17. protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException \{
18. *//设置响应内容类型*
19. resp.setContentType( "text/html");
20. 
21. *//设置逻辑实现*
22. PrintWriter out = resp.getWriter();
23. out.println( "<h1>" \+ message + "</h1>");
24. \}
25. 
26. @Override
27. public void destroy()\{
28. super.destroy();
29. \}
30. \}

编译后会发现在classes目录下生成了HelloWorld.class文件  
![SouthEast][]  
  
  
2. 部署servlet  
方法一：  
    在WEB-INF目录下web.xml文件的<web-app>标签中添加如下内容：

<servlet>
            <servlet-name>HelloWorld</servlet-name>
            <servlet-class>HelloWorld</servlet-class>
        </servlet>
    
        <servlet-mapping>
            <servlet-name>HelloWorld</servlet-name>
            <url-pattern>/HelloWorld</url-pattern>
        </servlet-mapping>

方法二：  
在HelloWorld文件的类前面加上：@WebServlet("/HelloWorld")  
  
  
3. 运行servlet  
点击运行按钮  
![SouthEast 1][]

控制台出现successfully则tomcat服务启动成功！打开浏览器输入：localhost:8080/JavaWeb/HelloWorld即可查看servlet运行状态了.

![SouthEast 2][]

[SouthEast]: /images/20220521/3428c0e2430a4ae59cf9cf7dc28a3029.png
[SouthEast 1]: /images/20220521/27349754bb614354ae8995014ec89a0e.png
[SouthEast 2]: /images/20220521/2eb255ccef524178baaff60afb89b1c2.png