AsyncTask致命异常＃1

  • Z时代
  • 2024-01-10
  • 分类：问答

我有一个使用通道将文本文件下载到本地文件的asynctask。AsyncTask致命异常＃1

class getUrlsClass extends AsyncTask<String, Integer, File>{ 
    @Override 
    protected File doInBackground(String... params) { 
     URLConnection uc; 
     File urlFiles= new File(getApplicationContext().getFilesDir(), "urls"); 
     try { 
      URL url = new URL(params[0]); 
      uc = url.openConnection(); 
      uc.setUseCaches(false); 
      ReadableByteChannel rbc = Channels.newChannel(uc.getInputStream()); 
      FileOutputStream fos = new FileOutputStream(urlFiles); 
      fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE); 
      fos.close(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
     return null; 
    } 
}

，我得到一个致命的运行时异常，会使得程序崩溃的开始：

07-22 01:31:01.769: E/AndroidRuntime(27610): FATAL EXCEPTION: AsyncTask #1 
07-22 01:31:01.769: E/AndroidRuntime(27610): Process: com.example.griding, PID: 27610 
07-22 01:31:01.769: E/AndroidRuntime(27610): java.lang.RuntimeException: An error occured while executing doInBackground() 
07-22 01:31:01.769: E/AndroidRuntime(27610): at android.os.AsyncTask$3.done(AsyncTask.java:300) 
07-22 01:31:01.769: E/AndroidRuntime(27610): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355) 
07-22 01:31:01.769: E/AndroidRuntime(27610): at java.util.concurrent.FutureTask.setException(FutureTask.java:222) 
07-22 01:31:01.769: E/AndroidRuntime(27610): at java.util.concurrent.FutureTask.run(FutureTask.java:242) 
07-22 01:31:01.769: E/AndroidRuntime(27610): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231) 
07-22 01:31:01.769: E/AndroidRuntime(27610): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) 
07-22 01:31:01.769: E/AndroidRuntime(27610): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587) 
07-22 01:31:01.769: E/AndroidRuntime(27610): at java.lang.Thread.run(Thread.java:841) 
07-22 01:31:01.769: E/AndroidRuntime(27610): Caused by: java.lang.IllegalArgumentException: position=0 count=9223372036854775807 
07-22 01:31:01.769: E/AndroidRuntime(27610): at java.nio.FileChannelImpl.transferFrom(FileChannelImpl.java:368) 
07-22 01:31:01.769: E/AndroidRuntime(27610): at com.example.myApp.DownloadManagerActivity$getUrlsClass.doInBackground(DownloadManagerActivity.java:284) 
07-22 01:31:01.769: E/AndroidRuntime(27610): at com.example.myApp.DownloadManagerActivity$getUrlsClass.doInBackground(DownloadManagerActivity.java:1) 
07-22 01:31:01.769: E/AndroidRuntime(27610): at android.os.AsyncTask$2.call(AsyncTask.java:288) 
07-22 01:31:01.769: E/AndroidRuntime(27610): at java.util.concurrent.FutureTask.run(FutureTask.java:237) 
07-22 01:31:01.769: E/AndroidRuntime(27610): ... 4 more

什么是任务的问题？

回答：

唯一的例外是在引起：

fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);

因为参数count不能超过Integer.MAX_VALUE更大。这是造成这种特殊的例外！

在FileChannelImpl类文件发现这一点：

if (position < 0 || count < 0 || count > Integer.MAX_VALUE) { 
     throw new IllegalArgumentException("position=" + position + " count=" + count); 
    }

希望它能帮助！ :)

以上是 AsyncTask致命异常＃1 的全部内容， 来源链接： utcz.com/qa/267126.html

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