1.初始Servlet
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class HelloServletTest extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=GBK");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println(" <head><title>Servlet</title></head>");
out.println(" <body>");
out.println("你好，欢迎来到Servlet世界");
out.println(" </body>");
out.println("</html>");
out.close();
}
}
1.1在web.xml配置Servlet
<web-app>
<servlet>
<servlet-name>对象名</servlet-name>
<servlet-class>配置servlet的完整类名/全限定名：包名+类名</servlet-class>
<init-param>
<param-name>initParam</param-name>
<param-value>Hello Servlet</param-value>
</init-param>
</servlet>
<servlet-mapping>
<!-- /:localhost:8080/项目名 -->
<servlet-name>对象名</servlet-name>
<url-pattern>/路径.do</url-pattern>
</servlet-mapping>
</web-app>
1.2 获取初始化参数
public class IndexServlet extends HttpServlet{
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//设置编码
req.setCharacterEncoding("utf-8");
resp.setContentType("text/html;charset=utf-8");
// 2.获取 out 内置对象
PrintWriter out = resp.getWriter();
}2. 常用的九个jsp内置对象
request：请求
response：响应
session：会话
out：输出/打印
application：应用程序
pageContext：页面上下文对象
exception：对象表示的就是JSP引擎在执行代码过程中抛出的种种异常,只有在page指令中设置isErrorPage="true"的页面中才能使用。
page：页面对象
config：配置对象
3.实现Servlet的三种方式
实现Servlet的三种方式：一个实现，两个继承
3.1第一种方法，实现Servlet接口
package com.xinqi.sevlet;
2
3 import java.io.IOException;
4
5 import javax.servlet.Servlet;
6 import javax.servlet.ServletConfig;
7 import javax.servlet.ServletException;
8 import javax.servlet.ServletRequest;
9 import javax.servlet.ServletResponse;
10
11 public class testServlet1 implements Servlet {
12
13 /**
14 * 销毁方法
15 */
16 public void destroy() {
17 System.out.println("这是销毁方法！");
18
19 }
20
21 /**
22 * 初始化方法
23 */
24 public void init(ServletConfig arg0) throws ServletException {
25 System.out.println("这是初始化方法！");
26 }
27
28 /**
29 * 服务方法
30 */
31 public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {
32
33 System.out.println("这是服务方法！");
34
35 }
36
37
38 //获取servlet配置信息
39 public ServletConfig getServletConfig() {
40
41 return null;
42 }
43
44 //获取servlet信息
45 public String getServletInfo() {
46
47 return null;
48 }
49 }3.2第二种方法：继承GenericServlet抽象类
GenericServlet抽象类中只有一个抽象方法service()方法
1 package com.xinqi.sevlet;
2
3 import java.io.IOException;
4
5 import javax.servlet.GenericServlet;
6 import javax.servlet.ServletException;
7 import javax.servlet.ServletRequest;
8 import javax.servlet.ServletResponse;
9
10 public class testServlet2 extends GenericServlet{
11
12 @Override
13 public void service(ServletRequest arg0, ServletResponse arg1) throws ServletException, IOException {
14
15 System.out.println("这是服务方法！");
16 }
17
18 }3.3第三种方式：继承HttpServlet抽象类重写doPut()和doPost()方法
1 package com.xinqi.sevlet;
2
3 import java.io.IOException;
4
5 import javax.servlet.ServletException;
6 import javax.servlet.http.HttpServlet;
7 import javax.servlet.http.HttpServletRequest;
8 import javax.servlet.http.HttpServletResponse;
9
10 public class testServlet3 extends HttpServlet{
11
12 @Override
13 protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
14
15 System.out.println("这是get方法提交");
16
17 doGet(req, resp);
18 }
19
20
21 @Override
22 protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
23 System.out.println("这是post方法提交");
24 }
25
26 }