Java Servlet在调用时不显示任何内容
过了一会儿,我正在为servlet/jsp编写代码 当我调用servlet时,它给了我一个空白的浏览器,甚至没有错误 我的Jsp:Java Servlet在调用时不显示任何内容,java,jsp,servlets,Java,Jsp,Servlets,过了一会儿,我正在为servlet/jsp编写代码 当我调用servlet时,它给了我一个空白的浏览器,甚至没有错误 我的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
<%@ 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>Insert title here</title>
</head>
<body>
<form action="HelloServlet" method="POST">
Please enter a color <br>
<input type="text" name="color"size="20px">
<input type="submit" value="submit">
</form>
</body>
</html>
在此处插入标题
请输入颜色
我的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 HelloServlet
*/
@WebServlet("/HelloServlet")
public class HelloServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public HelloServlet() {
super();
// TODO Auto-generated constructor 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
System.out.println("Servlet called...");
String color = request.getParameter("color");
PrintWriter out = response.getWriter();
/*
* out.println(
*
* "<html> \n" + "<head> \n" +
* "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=ISO-8859-1\"> \n"
* + "<title> My first jsp </title> \n" + "</head> \n" + "<body> \n" +
* "<font size=\"12px\" color=\"" + color + "\">" + "Hello World" +
* "</font> \n" + "</body> \n" + "</html>");
*/
out.println("Aman.............");
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
* response)
*/
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
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HelloServlet
*/
@WebServlet(“/HelloServlet”)
公共类HelloServlet扩展了HttpServlet{
私有静态最终长serialVersionUID=1L;
/**
*@参见HttpServlet#HttpServlet()
*/
公共HelloServlet(){
超级();
//TODO自动生成的构造函数存根
}
/**
*@参见HttpServlet#服务(HttpServletRequest,HttpServletResponse
*(答复)
*/
受保护的无效服务(HttpServletRequest),
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
*(答复)
*/
受保护的无效数据集(HttpServletRequest请求,
HttpServletResponse响应)引发ServletException,IOException{
//TODO自动生成的方法存根
System.out.println(“Servlet调用…”);
字符串颜色=request.getParameter(“颜色”);
PrintWriter out=response.getWriter();
/*
*out.println(
*
*“\n”+“\n”+
*“\n”
*+“我的第一个jsp\n”+“\n”+“\n”+
*“+”你好,世界”+
*“\n”+”\n“+”);
*/
out.println(“阿曼…………”);
}
/**
*@参见HttpServlet#doPost(HttpServletRequest,HttpServletResponse
*(答复)
*/
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
doGet(请求、响应);
}
}
和web.xml:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<servlet>
<servlet-name>HelloServlet</servlet-name>
<servlet-class>HelloServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloServlet</servlet-name>
<url-pattern>/HelloServlet</url-pattern>
</servlet-mapping>
<display-name>TestApp</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>
</web-app>
HelloServlet
HelloServlet
HelloServlet
/HelloServlet
特斯塔普
index.html
index.htm
index.jsp
default.html
default.htm
default.jsp
请帮我解决这个问题
谢谢
Aman您犯的错误是既使用
注释
,又通过部署描述符(web.xml
)注册servlet
如果使用注释,则不需要通过部署描述符注册servlet。但是您应该有tomcat7,因为它不会在以前的tomcat版本中运行。用于映射具有指定名称的servlet
此外,我假设您没有使用任何包,因为在url映射中您无法指定一个包。但是,如果您正在使用名为mypackage
的包,并且您的servlet类在其中,那么请将url映射更改为如下内容
<servlet>
<servlet-name>HelloServlet</servlet-name>
<servlet-class>mypackage.HelloServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloServlet</servlet-name>
<url-pattern>/HelloServlet</url-pattern>
</servlet-mapping>
HelloServlet
mypackage.HelloServlet
HelloServlet
/HelloServlet
将super添加到以下函数中,一切都将正常工作
protected void service(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
**super(request, response) // add this**
}
service()方法是执行实际任务的主要方法。servlet容器(即web服务器)调用service()方法来处理来自客户端(浏览器)的请求
您已经重写了负责调用doget和post的函数
希望这能解决您的查询受保护的服务方法检查请求的类型,如果请求类型为get,它将调用doGet方法,如果请求类型为post,它将调用doPost方法,依此类推 尝试删除此方法,您的servlet应该可以工作
protected void service(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
或者使用以下命令重写您的服务方法:
protected void service(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
String method = request.getMethod();
if(method.equals("GET"))
doGet(request, response);
else
doPost(request, response);
}
您不需要在服务方法中写入任何内容,这样它就不会调用doPost或doGet您是否正在控制台中获取system.out日志。。比如“调用Servlet”由于您正在使用批注,请从web上删除映射。xml@ParasMittal:不,我也没有在控制台中获取syout。@M.Sharma:我尝试从web.xml中删除映射,但还没有成功。请确保在按照我所说的重新发布应用程序之后,您有tomcat 7进行注释。我还构建并重新启动了服务器。