Java - Android - ZIP文件不斷帶回println需要消息錯誤

Question

我只是想壓縮兩個文件。有一個調用Compress類的MainActivity。看起來Compress.zip（）方法中的循環正在循環，但在out.close（）之前它會給出錯誤？這是因爲我沒有創建的zip文件？如果是的話，我該如何檢查？

這裏是代碼：

public class MainActivity extends Activity { 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
       Environment.DIRECTORY_PICTURES), "MyCameraApp"); 
     if (! mediaStorageDir.exists()){ 
      if (! mediaStorageDir.mkdirs()){ 
       Log.d("MyCameraApp", "failed to create directory"); 

      } 
     } 
     String path = mediaStorageDir.getPath() + File.separator; 
     String zip = path+"images.zip"; 
     String[] files = new String[3]; 
     files[0] = path+"IMG_1.jpg"; 
     files[1] = path+"IMG_2.jpg"; 
     Compress comp = new Compress(files, zip); 
     comp.zip(); 
    } 
} 




public class Compress { 
    private static final int BUFFER = 2048; 
    private String[] mfiles; 
    private String mzip; 

    public Compress(String[] files, String zip){ 
     mfiles = files; 
     mzip = zip; 
    } 

    public void zip(){ 
     try{ 
      BufferedInputStream origin = null; 
      FileOutputStream dest = new FileOutputStream(mzip); 
      ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(dest)); 
      byte data[] = new byte[BUFFER]; 
      for(int i=0; i< mfiles.length;i++){ 
       Log.v("Compress", mfiles[i]); 
       FileInputStream fi = new FileInputStream(mfiles[i]); 
       origin = new BufferedInputStream(fi, BUFFER); 
       ZipEntry entry = new ZipEntry(mfiles[i].substring(mfiles[i].lastIndexOf("/")+1)); 
       out.putNextEntry(entry); 
       int count; 
       while((count = origin.read(data, 0, BUFFER)) != -1){ 
        out.write(data, 0, count); 
       } 
       origin.close(); 
      } 
      out.close(); 

     }catch(Exception e){ 
      e.printStackTrace(); 
     } 
    } 
} 

錯誤信息

09-19 08:41:40.911: V/Compress(5910): /storage/emulated/0/Pictures/MyCameraApp/IMG_1.jpg 
09-19 08:41:41.282: V/Compress(5910): /storage/emulated/0/Pictures/MyCameraApp/IMG_2.jpg 
09-19 08:41:41.602: W/System.err(5910): java.lang.NullPointerException: println needs a message 
09-19 08:41:41.602: W/System.err(5910):  at android.util.Log.println_native(Native Method) 
09-19 08:41:41.602: W/System.err(5910):  at android.util.Log.v(Log.java:119) 
09-19 08:41:41.602: W/System.err(5910):  at net.assemblyx.damage.Compress.zip(Compress.java:30) 
09-19 08:41:41.602: W/System.err(5910):  at net.assemblyx.damage.MainActivity.onCreate(MainActivity.java:38) 
09-19 08:41:41.602: W/System.err(5910):  at android.app.Activity.performCreate(Activity.java:5372) 
09-19 08:41:41.602: W/System.err(5910):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104) 
09-19 08:41:41.602: W/System.err(5910):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2267) 
09-19 08:41:41.602: W/System.err(5910):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2359) 
09-19 08:41:41.602: W/System.err(5910):  at android.app.ActivityThread.access$700(ActivityThread.java:165) 
09-19 08:41:41.602: W/System.err(5910):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1326) 
09-19 08:41:41.602: W/System.err(5910):  at android.os.Handler.dispatchMessage(Handler.java:99) 
09-19 08:41:41.602: W/System.err(5910):  at android.os.Looper.loop(Looper.java:137) 
09-19 08:41:41.602: W/System.err(5910):  at android.app.ActivityThread.main(ActivityThread.java:5455) 
09-19 08:41:41.602: W/System.err(5910):  at java.lang.reflect.Method.invokeNative(Native Method) 
09-19 08:41:41.602: W/System.err(5910):  at java.lang.reflect.Method.invoke(Method.java:525) 
09-19 08:41:41.602: W/System.err(5910):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1187) 
09-19 08:41:41.602: W/System.err(5910):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003) 
09-19 08:41:41.602: W/System.err(5910):  at dalvik.system.NativeStart.main(Native Method) 

Answer 1

的堆棧跟蹤說的println需要有一個消息。

Log.v("Compress", mfiles[i]); 

如果mfiles[i]爲null，它將使與該消息的應用程序崩潰。改變它

Log.v("Compress", mfiles[i] != null ? mfiles[i] : " mfiles at i is null");