Android -空对象引用，正在解析RSS文件
Android -空对象引用，正在解析RSS文件
提问于 2016-08-17 16:54:38
有人能帮我理解这个错误吗？我尝试解析xml文件并获取其内容。但每次我收到这个错误。有很多人都有类似的错误，但还没有帮助到我。
08-17 10:34:18.589 25213-25567/com.example.entwicklung1.designtestapp E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #2
Process: com.example.entwicklung1.designtestapp, PID: 25213
java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:309)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'org.w3c.dom.NodeList org.w3c.dom.Node.getChildNodes()' on a null object reference
at com.example.entwicklung1.designtestapp.ReadRssZander.ProcessXml(ReadRssZander.java:66)
at com.example.entwicklung1.designtestapp.ReadRssZander.doInBackground(ReadRssZander.java:58)
at com.example.entwicklung1.designtestapp.ReadRssZander.doInBackground(ReadRssZander.java:29)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)以下是我的代码的一部分。我甚至找不到带有"item“的子项。我在这里已经得到了错误：NodeList items = channel.getChildNodes();
@Override
protected Void doInBackground(Void... params) {
ProcessXml(Getdata());
return null;
}
private void ProcessXml(Document data) {
if(data!=null) {
Element root = data.getDocumentElement();
Node channel = root.getChildNodes().item(1);
NodeList items = channel.getChildNodes();
//for(int i=0;i<items.getLength();i++){
// Node currentchild = items.item(i);
// Log.d("textcontent",currentchild.getTextContent());
// if(currentchild.getNodeName().equalsIgnoreCase("item")){
// NodeList itemchilds=currentchild.getChildNodes();
// for(int j=0;j<itemchilds.getLength();j++){
// Node current= itemchilds.item(j);
// Log.d("textcontent",current.getTextContent());
// }
// }
//}
}
}
public Document Getdata(){
try {
url = new URL(adress);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
InputStream inputStrem = connection.getInputStream();
DocumentBuilderFactory builderFactory=DocumentBuilderFactory.newInstance();
DocumentBuilder builder=builderFactory.newDocumentBuilder();
Document xmlDoc =builder.parse(inputStrem);
return xmlDoc;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}这是XML文件，我尝试解析：Link
回答 1
Stack Overflow用户
回答已采纳
发布于 2016-08-17 17:20:38
我找到了解决我的问题的办法。我找错东西了。
我需要的正确项目是Node channel = root.getChildNodes().item(0);而不是Node channel = root.getChildNodes().item(1);
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/38992120
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