解析某个特定网站时Android应用程序崩溃

Question

我试图构建我的第一个Android应用程序，用于我学校的新闻发布。我使用Jsoup，但每次都会崩溃。这个问题只发生在这个网页上。当我输入不同的网址时，它就可以工作。这里是链接的页面：http://www.marianum24.de/~aushang/index.html 这里是我的代码：

private String loadXmlFromNetwork(String urlString) throws IOException { 

    Document doc = null; 
    StringBuilder htmlString = new StringBuilder(); 

    try { 
     doc = Jsoup.connect(urlString).get(); 
     htmlString.append(doc.body().text()); 
    } catch (IOException e) { 
     return getResources().getString(R.string.connection_error); 
    } 

    return htmlString.toString(); 
} 

最后我的日志：

11-27 11:30:33.081: D/gralloc_goldfish(5227): Emulator without GPU emulation detected. 
11-27 11:30:35.251: D/dalvikvm(5227): GC_FOR_ALLOC freed 149K, 9% free 2768K/3024K, paused 51ms, total 51ms 
11-27 11:30:36.292: D/dalvikvm(5227): GC_FOR_ALLOC freed 398K, 15% free 2881K/3380K, paused 50ms, total 51ms 
11-27 11:30:37.411: D/dalvikvm(5227): GC_FOR_ALLOC freed 181K, 9% free 3215K/3496K, paused 59ms, total 59ms 
11-27 11:30:37.952: W/dalvikvm(5227): threadid=12: thread exiting with uncaught exception (group=0x414c4700) 
11-27 11:30:37.971: E/AndroidRuntime(5227): FATAL EXCEPTION: AsyncTask #1 
11-27 11:30:37.971: E/AndroidRuntime(5227): java.lang.RuntimeException: An error occured while executing doInBackground() 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at android.os.AsyncTask$3.done(AsyncTask.java:299) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at java.util.concurrent.FutureTask.setException(FutureTask.java:219) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at java.util.concurrent.FutureTask.run(FutureTask.java:239) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at java.lang.Thread.run(Thread.java:841) 
11-27 11:30:37.971: E/AndroidRuntime(5227): Caused by: java.lang.NullPointerException 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at com.boldog.aushang.MainActivity.loadXmlFromNetwork(MainActivity.java:199) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at com.boldog.aushang.MainActivity.access$0(MainActivity.java:192) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at com.boldog.aushang.MainActivity$DownloadXmlTask.doInBackground(MainActivity.java:175) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at com.boldog.aushang.MainActivity$DownloadXmlTask.doInBackground(MainActivity.java:1) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at android.os.AsyncTask$2.call(AsyncTask.java:287) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  at java.util.concurrent.FutureTask.run(FutureTask.java:234) 
11-27 11:30:37.971: E/AndroidRuntime(5227):  ... 4 more 
11-27 11:30:42.774: I/Choreographer(5227): Skipped 78 frames! The application may be doing too much work on its main thread. 
11-27 11:31:28.801: I/Process(5227): Sending signal. PID: 5227 SIG: 9 

我希望你能告诉我问题所在。

Answer 1

检查MainActivity 199行。那里有null。

我敢打赌，在这条线：

htmlString.append(doc.body().text()); 

我想doc可能是null。

Answer 2

您的问题似乎是一个验证问题。简而言之，您将原始HTML文件传递给您的Document对象，就好像它是格式正确的XML一样。事实并非如此。按照w3.org验证服务，

http://validator.w3.org/check?uri=http%3A%2F%2Fwww.marianum24.de%2F~aushang%2Findex.html&charset=%28detect+automatically%29&doctype=Inline&group=0

此时至少有8个错误和警告1与网站。

如果我是你，我会运行一些检查来解析我的输入文件之前做任何处理。