java - HttpUrlConnection : how to get the XML response into a String?

Question

我正在使用 HttpURLConnection 发布到 REST API。我仍然没有成功发布任何内容，所以我试图取回应该来自 API 的 XML 响应。

这是我放在一起的代码段，它给我带来了问题:

// Process response - need to get XML response back.
InputStream stream = connection.getInputStream();
connection.disconnect();

BufferedReader br = new BufferedReader(stream);
String result;
String line;
while ((line = br.readLine()) != null) {
    System.out.println(line);
    result += line;
}
br.close();

编译器对这一行不满意(建议的修复是“将流类型更改为读取器”):

BufferedReader br = new BufferedReader(stream);

有人对我如何正确执行此操作有任何建议吗？ 任何帮助表示赞赏。

完整代码在这里:

package com.gwt.HelpDeskTest.server;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;

import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import com.gwt.HelpDeskTest.client.HelpDeskTestService;
import com.gwt.HelpDeskTest.shared.HelpDeskTestException;

@SuppressWarnings("serial")
public class HelpDeskTestImpl extends RemoteServiceServlet implements HelpDeskTestService {

    @Override
    public String postToRemoteServer(String serviceUrl) throws HelpDeskTestException {
        try {
            final String serverPath= "http://helpdesk.rmi.org/sdpapi/request/";     
            final String serverParameters = "OPERATION_NAME=ADD_REQUEST&TECHNICIAN_KEY=D4ADD3A3-9CD4-4307-932B-29E96BCFA5B6&INPUT_DATA=%3C?xml%20version=%25221.0%2522%20encoding=%2522utf-8%2522?%3E%3COperation%3E%3CDetails%3E%3Crequester%3EBetsy%20Leach%3C/requester%3E%3Csubject%3ETest%3C/subject%3E%3Cdescription%3ETesting%20curl%20input%20again%3C/description%3E%3C/Details%3E%3C/Operation%3E"; // Put parameters here for testing.

            // trying HttpURLConnection instead of a plain URLConnection

            URL url = new URL(serverPath); 
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();           
            connection.setDoOutput(true);
            connection.setDoInput(true);
            connection.setInstanceFollowRedirects(false); 
            connection.setRequestMethod("POST"); 
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); 
            connection.setRequestProperty("charset", "utf-8");
            connection.setRequestProperty("Content-Length", "" + Integer.toString(serverParameters.getBytes().length));
            connection.setUseCaches (false);

            DataOutputStream wr = new DataOutputStream(connection.getOutputStream());
            wr.writeBytes(serverParameters);
            wr.flush();
            wr.close();

            // Process response - need to get XML response back.
            InputStream stream = connection.getInputStream();
            connection.disconnect();

            // Put output stream into a String
            BufferedReader br = new BufferedReader(stream);
            String result;
            String line;
            while ((line = br.readLine()) != null) {
                System.out.println(line);
                result += line;
            }
            br.close();

            System.out.println(result);
            return result;
        } 
        catch (final Exception e) {
            System.out.println(e.getMessage());
            throw new HelpDeskTestException();
        }
    }
}

Answer 1

我有两个观察结果。

1. 移动connection.disconnect();最后，您完成阅读的地方，即在 br.close(); 之后行。

2. 遵循以下顺序:

   InputStream stream = connection.getInputStream();
   InputStreamReader isReader = new InputStreamReader(stream ); 
   
   //put output stream into a string
   BufferedReader br = new BufferedReader(isReader );
   

希望有用!