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[英]HTTP Status 405 - HTTP method POST is not supported by this URL java servlet
[英]HTTP Status 405: HTTP method POST is not supported by this URL
我已经尝试了 StackOverflow 和 Internet 上可用的所有方法,但似乎没有按预期进行锻炼,以下是我尝试过的操作列表:
protected
,命名为doPost()
sendRedirect()
方法而不是RequestDispatcher()
doPost()
中调用它任何帮助将不胜感激,谢谢!
这是我的登录名。html
<!DOCTYPE html>
<html>
<head>
<title>Login</title>
</head>
<body>
<form action="auth" method="post">
<table>
<tr>
<td>Email ID:</td>
<td><input type="email" name="userEmail"></td>
</tr>
<tr>
<td>Password: </td>
<td><input type="password" name="userPassword"></td>
</tr>
<tr>
<td><input type="submit" value="Login"></td>
</tr>
</table>
</form>
</body>
</html>
验证.java
package newAuthentication;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class authenticate extends HttpServlet
{
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String userEmail = request.getParameter("userEmail");
String userPassword = request.getParameter("userPassword");
if (validateUser.checkUser(userEmail, userPassword))
{
HttpSession session = request.getSession();
session.setAttribute("userEmail", userEmail);
RequestDispatcher dispatch = request.getRequestDispatcher("home");
dispatch.forward(request, response);
}
else
{
out.println("Incorrect authentication credentials, please try again!");
RequestDispatcher dispatch = request.getRequestDispatcher("login.html");
dispatch.include(request, response);
}
}
}
validateUser.java
package newAuthentication;
import java.sql.*;
public class validateUser
{
public static boolean checkUser(String userEmail, String userPassword)
{
boolean state = false;
try
{
Class.forName("com.mysql.cj.jdbc.Driver");
Connection connect = DriverManager.getConnection("jdbc:mysql://localhost:3306/wad","root","root");
PreparedStatement fetchData = connect.prepareStatement("select * from studentData where email = ? and password = ?");
fetchData.setString(1, userEmail);
fetchData.setString(2, userPassword);
ResultSet data = fetchData.executeQuery();
state = data.next();
}
catch (Exception err)
{
err.printStackTrace();
}
return state;
}
}
主页.java
package newAuthentication;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class home extends HttpServlet
{
protected void doPost(HttpServletResponse response, HttpServletRequest request) throws ServletException, IOException
{
doGet(request, response);
response.setContentType("text/html");
PrintWriter out = response.getWriter();
HttpSession session = request.getSession();
String userEmail = (String)session.getAttribute("userEmail");
out.println("Welcome user " + userEmail);
}
}
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">
<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>newAuth</display-name>
<servlet>
<servlet-name>Login</servlet-name>
<servlet-class>newAuthentication.authenticate</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Login</servlet-name>
<url-pattern>/auth</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>Home</servlet-name>
<servlet-class>newAuthentication.home</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Home</servlet-name>
<url-pattern>/home</url-pattern>
</servlet-mapping>
<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>
为什么你首先会遇到这个问题:
这段代码太长了,无法一步完成。 特别是如果您没有使用 servlets 的经验。 如果您还不确定您的 servlets 和基本映射是否有效,请从小处着手 - 单个 servlet、单个 GET 映射 - 您可以在浏览器中尝试,无需任何 HTML。 整个项目中只有两个文件: web.xml
和MyServlet.java
- 并将doGet
方法留空。
现在,你的代码太长了,一旦你碰到它,你根本猜不到问题——有太多地方需要验证!
神奇的公式是:“一次只尝试一件事”。
解决方案:
删除 doPost 方法中的doGet(request, response)
调用。
您不提供自己的doGet
方法,因此它默认为超类中的内容。 碰巧的是,默认的doGet
方法会引发异常,指出不支持 GET 方法。 由于您从doPost
调用它,因此传播的异常使容器认为(正确地)它是您的doPost
正在抛出,因此它是不受支持的 POST 。
而且,这个电话毫无意义。
顺便说一句:请注意,如果您首先尝试使用建议的两种 class 方法,您会在 5 秒内发现此错误:您只需验证这一点。
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