Android文件读取简单操作

public class MainActivity extends ActionBarActivity {

final String FILE_NAME = "crazyit.bin";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

System.out.println(new StringBuilder("a").append("b").append("c").toString());

Button read = (Button) findViewById(R.id.read);
Button write = (Button) findViewById(R.id.write);

final EditText edit1 = (EditText) findViewById(R.id.edit1);
final EditText edit2 = (EditText) findViewById(R.id.edit2);

write.setOnClickListener(new OnClickListener() {

public void onClick(View v) {
write(edit1.getText().toString());
edit1.setText("");
}
});

read.setOnClickListener(new OnClickListener() {

public void onClick(View v) {
edit2.setText(read());
}
});

}

public void write(String content){
try {
FileOutputStream fos = openFileOutput(FILE_NAME, MODE_APPEND);
PrintStream ps = new PrintStream(fos);
ps.println(content);
ps.close();

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

}

public String read(){
try {
FileInputStream fis = openFileInput(FILE_NAME);
byte [] buff = new byte[1024];
int hasRead = 0;
StringBuilder builder = new StringBuilder("");
while ( (hasRead = fis.read(buff)) > 0 ) {
builder.append(new String(buff, 0, hasRead));
}
fis.close();
return builder.toString();

} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}

return null;

xml布局文件如下：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<Button
android:id="@+id/read"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Read" />

<Button
android:id="@+id/write"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Write" />

<EditText
android:id="@+id/edit1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10" >

<requestFocus />
</EditText>

<EditText
android:id="@+id/edit2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10" />

</LinearLayout>

}