如何使用Java从链接URL检索XML/RDF数据？

Question

我一直在尝试从URL中检索XML数据，并使用以下代码片段将其写入磁盘http://dbpedia.org/data/Berlin.rdf上的文件

URL urlObj = new URL("http://dbpedia.org/data/Berlin.rdf");
java.net.HttpURLConnection connection = (HttpURLConnection) urlObj.openConnection();
InputStream reader = new BufferedInputStream(connection.getInputStream());
BufferedReader breader = new BufferedReader(new InputStreamReader(reader));
String line;        
BufferedWriter writer = new BufferedWriter(new eWriter("resource.xml"));

while ((line = breader.readLine()) != null) {   
    // writes the line to the output file
    writer.write(line);

    System.out.println(line);
    }
writer.close();
connection.disconnect();

但我得到了这个错误：线程“main”java中出现异常。伊奥。IOException:服务器为URLhttp://dbpedia.org/data/Berlin.rdf返回了HTTP响应代码：502 怎么了？如何解决这个问题？提前谢谢