Problem when Unzipping

问题:

Hey, I'm trying to unzip a file using this class:

 public class Decompress {
 private String _zipFile; 
  private String _location; 

  public Decompress(String zipFile, String location) { 
    _zipFile = zipFile; 
    _location = location; 

    _dirChecker(""); 
  } 

  public void unzip() { 
    try  { 
      FileInputStream fin = new FileInputStream(_zipFile); 
      ZipInputStream zin = new ZipInputStream(fin); 
      ZipEntry ze = null; 
      while ((ze = zin.getNextEntry()) != null) { 
        Log.v("Decompress", "Unzipping " + ze.getName()); 

        if(ze.isDirectory()) { 
          _dirChecker(ze.getName()); 
        } else { 
          FileOutputStream fout = new FileOutputStream(_location + ze.getName()); 
          for (int c = zin.read(); c != -1; c = zin.read()) { 
            fout.write(c); 
          } 

          zin.closeEntry(); 
          fout.close(); 
        } 

      } 
      zin.close(); 
    } catch(Exception e) { 
      Log.e("Decompress", "unzip", e); 
    } 

  } 

  private void _dirChecker(String dir) { 
    File f = new File(_location + dir); 

    if(!f.isDirectory()) { 
      f.mkdirs(); 
    } 
  } 

}

Code in Main.java

           String zipFile = Environment.getExternalStorageDirectory() + "/tmp.zip"; 

    String unzipLocation = Environment.getExternalStorageDirectory() + "/tmp/"; 
    Decompress d = new Decompress(zipFile, unzipLocation); 
    d.unzip(); 

The problem is in this line: while ((ze = zin.getNextEntry()) != null) {

zin.getNextEntry() is always null! Can anyone tell me how to fix this? Thanks.

回答1:

Huh,

You're using the exact decompress class as I am and mine is working fine.

Are you 100% sure that your zipFile variable is accessing an actual file? Did you make sure to add the android.permission.WRITE_EXTERNAL_STORAGE to your manifest and your SDCard is not mounted to your computer?

If so you might try creating a File object using the zipFile path and run file.exists() just to be sure everything is set up as it should be. Good luck!