JavaWeb企业实训(一)servlet检测输入为空

form表单提交与url大同小异。

Myeclipse创建servlet会自动配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> <servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>CheckServlet</servlet-name>
<servlet-class>cn.edu.bzu.py.servlet.CheckServlet</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>CheckServlet</servlet-name>
<url-pattern>/servlet/CheckServlet</url-pattern>
</servlet-mapping>

</web-app>CheckServlet.java
package cn.edu.bzu.py.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class CheckServlet extends HttpServlet {

public CheckServlet() {
super();
}

public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

//System.out.println("hahahha");
//检查输入是否为空
String name = request.getParameter("uname");
response.setContentType("text/html;charset=utf8");
PrintWriter out = response.getWriter();
out.println("输入"+name);

out.close();

}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);

}

public void init() throws ServletException {
// Put your code here
}

}


把项目部署到tomcat之后，使用下面的url访问这个Servlet http://localhost:8080/MyJavaWeb/servlet/CheckServlet?uname=123