Question

我正在使用eclipse中的servlet开发一个Login应用程序。我创建了一个登录表单，其中包含两个文本字段（用于输入用户名和密码）和一个登录按钮。当用户单击此按钮时，它会重定向到LoginCheck页面，并在其中检查登录详细信息。但问题是，当我运行此项目时，我收到错误：HTTP状态405 - 此URL不支持HTTP方法POST。我做的问题是什么？

以下是LoginPage的代码：

public class LoginPage extends HttpServlet {
   protected void doGet(HttpServletRequest request, HttpServletResponse   response) throws ServletException, IOException {
   response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<form method='post' actin='LoginCheck'>");
            out.println("Username: <input type='text' name='username'>");
            out.println("Password: <input type='password' name='password'>");
            out.println("<input type='submit' value='login'>");
        out.println("</form>");
    }
}

现在，当用户点击“登录”按钮时，必须转到此页面的LoginCheck页面代码，如下所示：

public class LoginCheck extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<h3>Checking login details...</h3>");
    }
}

在这里它给出了问题。

这是XML文件：

    <?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_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>LoginApp</display-name>
  <servlet>
    <servlet-name>LoginPage</servlet-name>
    <servlet-class>LoginPage</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>LoginPage</servlet-name>
    <url-pattern>/LoginPage</url-pattern>
  </servlet-mapping>


  <servlet>
    <servlet-name>LoginCheck</servlet-name>
    <servlet-class>LoginCheck</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>LoginCheck</servlet-name>
    <url-pattern>/LoginCheck</url-pattern>
  </servlet-mapping>
</web-app>

Answer 1

看起来你实际上并没有重定向到LoginCheck servlet。尝试使用request.getContextPath代替您拥有的内容。这是完整的代码：

public class LoginPage extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse   response) throws ServletException, IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        String contextPath = request.getContextPath();
        out.println("<form method='post' action='/" + contextPath + "/LoginCheck'>");
        out.println("Username: <input type='text' name='username'>");
        out.println("Password: <input type='password' name='password'>");
        out.println("<input type='submit' value='login'>");
        out.println("</form>");
    }
}

Answer 2

如果方法“get”重定向到“post”，则您的GET请求将转换为POST，从而丢失所有获取数据。所以我的建议是，从doGet方法调用doPost方法，如...

protected void doPost(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {

        PrintWriter out = resp.getWriter();
        out.println("<html><form method='post' action='LoginCheck'>");
        out.println("Username: <input type='text' name='username'>");
        out.println("Password: <input type='password' name='password'>");
        out.println("<input type='submit' value='login'>");
        out.println("</form></html>");
}

protected void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {
      doPost(req, resp);
}

为什么我收到错误＆＃34;此网址不支持HTTP方法帖子＆＃34;？

2 个答案: