servlet创建

佚名 6年前 (2019-05-12) 随笔 713人围观抢沙发百度已收录

servlet是一个在服务器上运行的小程序。一个servlet就是一个java类。并且可以通过“请求-相应”编程模型来访问这个驻留在服务器内存里的servlet程序。
继承HttpServlet
重写doGet()或doPost()方法
在web.xml中注册servlet
Servlet ：
package servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class TestServlet
*/
@WebServlet("/TestServlet")
public class TestServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// TODO Auto-generated method stub
PrintWriter out=resp.getWriter();
out.println("hello--");
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// TODO Auto-generated method stub
PrintWriter out=resp.getWriter();
out.println("world");
}
}

web.xml ：
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi=" http://www.w3.org/2001/XMLSchema-instance" xmlns=" http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation=" http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" id="WebApp_ID" version="4.0">
<display-name>Test</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>TestServlet</servlet-name>
<servlet-class>servlet.TestServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>TestServlet</servlet-name>
<url-pattern>/servlet/TestServlet</url-pattern>
</servlet-mapping>
</web-app>