Question

我有以下代码，但是当我尝试访问/ data-upload网址时，我收到错误“此方法不支持HTTP方法GET。”

Java servlet代码：

package xyz.controllers;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.entity.StringEntity;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServlet;
import javax.servlet.annotation.WebServlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;

@WebServlet("/data-upload")
public class GetLocalAreaIds extends HttpServlet {

    // HTTP POST request
    public void doPost(HttpServletRequest request, HttpResponse response) throws ServletException, IOException {  
        System.out.println("#VH in doPost method ");
        String url = "http://xyz.xyz/search";

        HttpClient client = new DefaultHttpClient();
        HttpPost post = new HttpPost(url);

        // add header
        post.setHeader("Content-Type", "application/xml");

        String elementLocalNameType = request.getParameter("elementLocalNameType");
        System.out.println("#VH elementLocalNameType: " + elementLocalNameType);

        String localAreaName = request.getParameter("localAreaName");
        System.out.println("#VH localAreaName: " + localAreaName);

        StringEntity params = null;
        try {
            params = getStringEntityParams(elementLocalNameType, localAreaName);
            System.out.println("#VH params: " + params);
        }
        catch (Exception e) {
            System.out.println("Error while getting elementLocalNameType");
        }

        post.setEntity(params);
        response = client.execute(post);
        System.out.println("\nSending 'POST' request to URL : " + url);
        System.out.println("Post parameters : " + post.getEntity());
        System.out.println("Response Code : " +
                response.getStatusLine().getStatusCode());

        BufferedReader rd = new BufferedReader(
                new InputStreamReader(response.getEntity().getContent()));

        StringBuffer result = new StringBuffer();
        String line = "";
        while ((line = rd.readLine()) != null) {
            result.append(line);
        }

        System.out.println("#VH result.toString(): " + result.toString());
    }

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

    private StringEntity getStringEntityParams(String elementLocalNameType, String localAreaName) throws Exception {
        StringEntity params = new StringEntity("<request><workflow>get-element-values-workflow</workflow><get-element-values><element-localname>"+elementLocalNameType+"</element-localname><starts-with>"+localAreaName+"</starts-with><is-csv>True</is-csv></get-element-values></request>");
        return params;
    }
}

JSP代码：

<%@ taglib prefix="tiles" uri="http://tiles.apache.org/tags-tiles" %>
<%@ taglib prefix="user" uri="/WEB-INF/tlds/user.tld" %>

<%@ page import="org.apache.http.client.HttpClient" %>
<%@ page import="org.apache.http.client.methods.HttpGet" %>
<%@ page import="org.apache.http.impl.client.DefaultHttpClient" %>
<%@ page import="GetLocalAreaIds" %>

<%@ taglib uri = "http://java.sun.com/jsp/jstl/core" prefix = "c" %>

<tiles:insertDefinition name="layout">
    <tiles:putAttribute name="title">Title</tiles:putAttribute>

  <tiles:putAttribute name="main">

        <main id="content" role="main" class="group category-page">
            <header class="page-header group">
                <div class="full-width">
                    <h1>Data Upload</h1>
                </div>
            </header>

            <div class="browse-container full-width group">
                        <div id="error">
                        <p style="color: #ff0000">${error}</p>
                </div>

                <user:current-local-area msg="<b>LA:</b> !{#localAreaName}"/>

                <c:set var = 'la_id' scope = 'session' value = '<user:current-local-area msg="!{#localAreaName}">'/>

                <c:set var = "la_id"><user:current-local-area msg="!{#localAreaName}"/></c:set>

                <jsp:useBean id="GetLocalAreaIds" class="GetLocalAreaIds"/>


                <form action="${pageContext.request.contextPath}/data-upload" method="POST">
                  <span>Do you want to download the LA IDs for families or individuals?</span><br />
                  <input type="radio" name="elementLocalNameType" value="la-family-id"> Family IDs<br />
                  <input type="radio" name="elementLocalNameType" value="la-individual-id"> Individual IDs<br />
                  <input type="hidden" name="localAreaName" value="${la_id}">
                  <input class="button" type="submit" value="Submit">
                </form>

            </div>

        </main>
        </tiles:putAttribute>
  </tiles:insertDefinition>

我已阅读其他一些处理同一问题的帖子，但他们的解决方案对我不起作用。当我尝试将@Override添加到doPost和doGet方法时，我收到一条错误，说“方法不会覆盖或实现超类型中的方法”，即使我正在扩展HttpServlet。

Answer 1

问题是，get和post都不是从HttpServlet继承的改变

doPost(HttpServletRequest request, HttpResponse response)

到

doPost(HttpServletRequest request, HttpServletResponse response)

和

doGet(HttpServletRequest request, HttpResponse response)

到

doGet(HttpServletRequest request, HttpServletResponse response)

修改下一期是

response = client.execute(post);

正如您所说"incompatible types: org.apache.http.HttpResponse cannot be converted to javax.servlet.http.HttpServletResponse"

将其更改为

org.apache.http.HttpResponse my_response = client.execute(post); ... System.out.println("Response Code : " + my_response.getStatusLine().getStatusCode()); BufferedReader rd = new BufferedReader( new InputStreamReader(my_response.getEntity().getContent()));

另请注意，您不会向用户响应输出任何内容，因此如果您在调用客户端（例如浏览器）时什么都没有，这是正常的。或者你用stdout写下你做的所有事情，然后回复。

从JSP调用servlet时，“HTTP状态405 - 此URL不支持HTTP方法GET”错误

1 个答案: