public class MainActivity extends AppCompatActivity { private TextView textView,textView2,textView3; private Button click; @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  textView = (TextView) findViewById(R.id.textView);  textView2 = (TextView) findViewById(R.id.textView2);  textView3 = (TextView) findViewById(R.id.textView3);  String s1 = Txt().get(0);//從Map get （key = 0）的value  String s2 = Txt().get(1);  String s3 = Txt().get(2);  textView.setText(s1);  textView2.setText(s2);  textView3.setText(s3); } public Map<Integer, String> Txt() {  //將讀出來的一行行數據使用Map存儲  String filePath = "/sdcard/sdl_log.txt";//手機上地址  Map<Integer, String> map = new HashMap<Integer, String>();  try {   File file = new File(filePath);   int count = 0;//初始化 key值   if (file.isFile() && file.exists()) {  //文件存在的前提    InputStreamReader isr = new InputStreamReader(new FileInputStream(file));    BufferedReader br = new BufferedReader(isr);    String lineTxt = null;    while ((lineTxt = br.readLine()) != null) {  //     if (!"".equals(lineTxt)) {      String reds = lineTxt.split("http://+")[0];  //java 正則表達式      map.put(count, reds);//依次放到map 0，value0;1,value2      count++;     }    }    isr.close();    br.close();   }else {    Toast.makeText(getApplicationContext(),"can not find file",Toast.LENGTH_SHORT).show();//找不到文件情況下   }  } catch (Exception e) {   e.printStackTrace();  }  return map; }}