一、读取SD卡指定后缀的所有文件
在实际开发过程中遇到了这样的需求， 要读取sd卡上所有的gif文件， 包括微信，微博等等保存下来的，实际上原理和删除文件差不多， 递归的调用删除：
MainActivity
public class MainActivity extends AppCompatActivity implements Handler.Callback{ private ImageView imageView; private ListView listView; private Adapters adapters; private List> list = new ArrayList<>(); private ListfileList = new ArrayList<>(); private Handler handler = new Handler(this); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final File path = Environment.getExternalStorageDirectory();// 获得SD卡路径; File[] files = path.listFiles();// 读取 final String URLpath = path.getAbsolutePath(); listView = (ListView) findViewById(R.id.listView); imageView = (ImageView) findViewById(R.id.imageView); imageView.setVisibility(View.VISIBLE); adapters = new Adapters(this,list); listView.setAdapter(adapters); new Thread(new Runnable() { @Override public void run() { getSuffixFile(fileList,URLpath,"mp3"); for (int i = 0 ;imap = new HashMap<>(); String zhengtilujin = fileList.get(i).toString(); String wenjianming = zhengtilujin.substring(zhengtilujin.lastIndexOf("/")+1); map.put("zhengtilujin",zhengtilujin); map.put("wenjianming",wenjianming); list.add(map); } Message message = new Message(); message.what = 1; handler.sendMessage(message); } }).start(); Student student = new Student.Builder() .setAddress() .setAge() .setName( .builder(); } /** * 读取sd卡上指定后缀的所有文件 * @param files 返回的所有文件 * @param filePath 路径(可传入sd卡路径) * @param suffere 后缀名称 比如 .gif * @return */ public ListgetSuffixFile(Listfiles, String filePath, String suffere) {
File f = new File(filePath);
if (!f.exists()) {
return null;
}
File[] subFiles = f.listFiles();
for (File subFile : subFiles) {
if(subFile.isFile() && subFile.getName().endsWith(suffere)){
files.add(subFile);
} else if(subFile.isDirectory()){
getSuffixFile(files, subFile.getAbsolutePath(), suffere);
} else{
//非指定目录文件 不做处理
}
}
return files;
}
@Override
public boolean handleMessage(Message message) {
switch (message.what){
case 1:
adapters.notifyDataSetChanged();
imageView.setVisibility(View.GONE);
listView.setVisibility(View.VISIBLE);
break;
}
return true;
}
}
Adapter
public class Adapters extends BaseAdapter{ private Context context; private List> list;
public Adapters(Context context,List list){
this.context = context;
this.list= list;
}
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int i) {
return list.get(i);
}
@Override
public long getItemId(int i) {
return i;
}
@Override
public View getView(int i, View view, ViewGroup viewGroup) {
ViewHolder viewHolder = null;
if (view==null){
viewHolder = new ViewHolder();
view = LayoutInflater.from(context).inflate(R.layout.item_layout,viewGroup,false);
viewHolder.imageView = (ImageView) view.findViewById(R.id.imageView); // 改变当前adapter imageView样式
viewHolder.textView = (TextView) view.findViewById(R.id.textView);
view.setTag(viewHolder);
}else {
viewHolder = (ViewHolder) view.getTag();
}
// map.put("zhengtilujin",zhengtilujin);
// map.put("wenjianming",wenjianming);
viewHolder.textView.setText(list.get(i).get("wenjianming").toString());
return view;
}
class ViewHolder {
ImageView imageView ;
TextView textView;
}
}
二、后来又需求要遍历文件中多种格式文件，我又改了改，可能逻辑有点繁琐但也能解决问题，等以后再优化吧，希望可以给大家个思路
private List<Map<String,Object>>list= new ArrayList<>();
File path = Environment.getExternalStorageDirectory();// 获得SD卡路径
final File [] files = path.listFiles();
if (files != null) {// 先判断目录是否为空，否则会报空指针
for (File file : files) {
if (file.isDirectory()) {
getFileName(file.listFiles());
} else {
String fileName = file.getName();
HashMap map = new HashMap();
if (fileName.endsWith(".txt")) {
map.put("Name", fileName.substring(0, fileName.lastIndexOf(".")) + ".txt");
list.add(map);
} else if (fileName.endsWith(".pdf")) {
map.put("Name", fileName.substring(0, fileName.lastIndexOf(".")) + ".pdf");
list.add(map);
} else if (fileName.endsWith(".docx")) {
map.put("Name", fileName.substring(0, fileName.lastIndexOf(".")) + ".docx");
list.add(map);
} else if (fileName.endsWith(".xlsx")) {
map.put("Name", fileName.substring(0, fileName.lastIndexOf(".")) + ".xlsx");
list.add(map);
} else if (fileName.endsWith(".pptx")) {
map.put("Name", fileName.substring(0, fileName.lastIndexOf(".")) + ".pptx");
list.add(map);
}
}
}
}
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