Java Servlet不';提交按钮后无法工作
servlets的新功能。以下是我的项目的布局:Java Servlet不';提交按钮后无法工作,java,jsp,servlets,Java,Jsp,Servlets,servlets的新功能。以下是我的项目的布局: Projectname src servlet.java web content META-INF WEB-INF first.jsp java的内容:它几乎只从jsp获取一个文本字段 import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletExcep
Projectname
src
servlet.java
web content
META-INF
WEB-INF
first.jsp
java的内容:它几乎只从jsp获取一个文本字段
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 servlet
*/
@WebServlet("/servlet")
public class servlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public servlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see Servlet#destroy()
*/
public void destroy() {
// TODO Auto-generated method stub
}
/**
* @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)
*/
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
String user=request.getParameter("string");
out.println("<h2> Welcome "+user+"</h2>");
} finally {
out.close();
}
}
}
import java.io.IOException;
导入java.io.PrintWriter;
导入javax.servlet.ServletException;
导入javax.servlet.annotation.WebServlet;
导入javax.servlet.http.HttpServlet;
导入javax.servlet.http.HttpServletRequest;
导入javax.servlet.http.HttpServletResponse;
/**
*Servlet实现类Servlet
*/
@WebServlet(“/servlet”)
公共类servlet扩展了HttpServlet{
私有静态最终长serialVersionUID=1L;
/**
*@参见HttpServlet#HttpServlet()
*/
公共servlet(){
超级();
//TODO自动生成的构造函数存根
}
/**
*@see Servlet#destroy()
*/
公共空间销毁(){
//TODO自动生成的方法存根
}
/**
*@参见HttpServlet#服务(HttpServletRequest请求,HttpServletResponse响应)
*/
受保护的无效服务(HttpServletRequest请求、HttpServletResponse响应)引发ServletException、IOException{
//TODO自动生成的方法存根
}
/**
*@参见HttpServlet#doGet(HttpServletRequest请求,HttpServletResponse响应)
*/
受保护的void doGet(HttpServletRequest请求,HttpServletResponse响应)抛出ServletException,IOException{
//TODO自动生成的方法存根
}
/**
*@请参阅HttpServlet#doPost(HttpServletRequest请求,HttpServletResponse响应)
*/
受保护的void doPost(HttpServletRequest请求、HttpServletResponse响应)引发ServletException、IOException{
//TODO自动生成的方法存根
setContentType(“text/html;charset=UTF-8”);
PrintWriter out=response.getWriter();
试一试{
String user=request.getParameter(“字符串”);
out.println(“欢迎”+用户+”);
}最后{
out.close();
}
}
}
jsp:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Input Form</title>
</head>
<body>
<form action="/servlet" method="POST">
What's your name:<br>
<input type="text" name="string">
<br>
<input type="submit" value="Submit">
</form>
</body>
</html>
输入表格
你叫什么名字:
最后是web.xml
<servlet>
<servlet-name>servlet</servlet-name>
<jsp-file>/first.jsp</jsp-file>
</servlet>
<servlet-mapping>
<servlet-name>servlet</servlet-name>
<url-pattern>/servlet</url-pattern>
</servlet-mapping>
servlet
/first.jsp
servlet
/servlet
问题是,我可以看到基本的jsp,它是提交字符串的表单,但当我单击submit时,什么也没有发生。我甚至不知道在哪里查找错误和日志来找出问题所在 我们在聊天和评论中讨论了一些问题:
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
/**
* Servlet implementation class servlet
*/
@WebServlet("/servlet")
public class servlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)
*/
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// Overriding service() usually isn't needed. - The default implementation mostly
// does the right thing®
super.service(request, response)
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// Just forward the request to the jsp page on get requests
request.getRequestDispatcher("/first.jsp").forward(request,response);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
String user=request.getParameter("string");
out.println("<h2> Welcome "+user+"</h2>");
} finally {
// Don't close the Response - it will mess with filters
// out.close();
out.flush()
}
}
}
import java.io.IOException;
导入java.io.PrintWriter;
导入javax.servlet.*;
导入javax.servlet.http.*;
导入javax.servlet.annotation.*;
/**
*Servlet实现类Servlet
*/
@WebServlet(“/servlet”)
公共类servlet扩展了HttpServlet{
私有静态最终长serialVersionUID=1L;
/**
*@参见HttpServlet#服务(HttpServletRequest请求,HttpServletResponse响应)
*/
受保护的无效服务(HttpServletRequest请求、HttpServletResponse响应)引发ServletException、IOException{
//通常不需要重写service()。-默认实现主要是
//做正确的事®;
超级服务(请求、响应)
}
/**
*@参见HttpServlet#doGet(HttpServletRequest请求,HttpServletResponse响应)
*/
受保护的void doGet(HttpServletRequest请求,HttpServletResponse响应)抛出ServletException,IOException{
//只需将请求转发到get请求的jsp页面
request.getRequestDispatcher(“/first.jsp”).forward(请求,响应);
}
/**
*@请参阅HttpServlet#doPost(HttpServletRequest请求,HttpServletResponse响应)
*/
受保护的void doPost(HttpServletRequest请求、HttpServletResponse响应)引发ServletException、IOException{
setContentType(“text/html;charset=UTF-8”);
PrintWriter out=response.getWriter();
试一试{
String user=request.getParameter(“字符串”);
out.println(“欢迎”+用户+”);
}最后{
//不要关闭响应-它会弄乱过滤器
//out.close();
冲水
}
}
}
我这样做了,但仍然不起作用。我在这里复制时忘记更改名称。反向是相同的s servlet。几乎删除了所有“${pageContext.request.contextPath}/servlet”引用。让我们看看。您的servlet service()方法为空,因此将永远不会调用doGet()和doPost()。