Android有没有文件选择器，类似Java的FileDialog与JFileChooser 没有的话该怎么实现呢？

Android有没有文件选择器，类似Java的FileDialog与JFileChooser 没有的话该怎么实现呢？

Java代码public class CopyOfFileChooserActivity extends Activity { private String mSdcardRootPath ; //sdcard 根路径 private String mLastFilePath ; //当前显示的路径 private ArrayList mFileLists ; private FileChooserAdapter mAdatper ; //配置适配器 private void setGridViewAdapter(String filePath) { updateFileItems(filePath); mAdatper = new FileChooserAdapter(this , mFileLists); mGridView.setAdapter(mAdatper); } //根据路径更新数据，并且通知Adatper数据改变 private void updateFileItems(String filePath) { mLastFilePath = filePath ; mTvPath.setText(mLastFilePath); if(mFileLists == null) mFileLists = new ArrayList() ; if(!mFileLists.isEmpty()) mFileLists.clear() ; File[] files = folderScan(filePath); if(files == null) return ; for (int i = 0; i < files.length; i++) { if(files[i].isHidden()) // 不显示隐藏文件 continue ; String fileAbsolutePath = files[i].getAbsolutePath() ; String fileName = files[i].getName(); boolean isDirectory = false ; if (files[i].isDirectory()){ isDirectory = true ; } FileInfo fileInfo = new FileInfo(fileAbsolutePath , fileName , isDirectory) ; //添加至列表 mFileLists.add(fileInfo); } //When first enter , the object of mAdatper don't initialized if(mAdatper != null) mAdatper.notifyDataSetChanged(); //重新刷新 } //获得当前路径的所有文件 private File[] folderScan(String path) { File file = new File(path); File[] files = file.listFiles(); return files; } private AdapterView.OnItemClickListener mItemClickListener = new OnItemClickListener() { public void onItemClick(AdapterView adapterView, View view, int position, long id) { FileInfo fileInfo = (FileInfo)(((FileChooserAdapter)adapterView.getAdapter()).getItem(position)); if(fileInfo.isDirectory()) //点击项为文件夹, 显示该文件夹下所有文件 updateFileItems(fileInfo.getFilePath()) ; else if(fileInfo.isPPTFile()){ //是ppt文件 ， 则将该路径通知给调用者 Intent intent = new Intent(); intent.putExtra(EXTRA_FILE_CHOOSER, fileInfo.getFilePath()); setResult(RESULT_OK , intent); finish(); } else { //其他文件..... toast(getText(R.string.open_file_error_format)); } } }; public boolean onKeyDown(int keyCode , KeyEvent event){ if(event.getAction() == KeyEvent.ACTION_DOWN && event.getKeyCode() == KeyEvent.KEYCODE_BACK){ backProcess(); return true ; } return super.onKeyDown(keyCode, event); } //返回上一层目录的操作 public void backProcess(){ //判断当前路径是不是sdcard路径 ， 如果不是，则返回到上一层。 if (!mLastFilePath.equals(mSdcardRootPath)) { File thisFile = new File(mLastFilePath); String parentFilePath = thisFile.getParent(); updateFileItems(parentFilePath); } else { //是sdcard路径 ，直接结束 setResult(RESULT_CANCELED); finish(); } } }