android点击生成private文件,append文件,read文件,write文件权限案例

MainActivity.java

 1 package com.example.prim;
 2 
 3 import java.io.FileInputStream;
 4 import java.io.FileNotFoundException;
 5 import java.io.FileOutputStream;
 6 
 7 import android.os.Bundle;
 8 import android.app.Activity;
 9 import android.view.Menu;
10 import android.view.View;
11 
12 public class MainActivity extends Activity {
13 
14     @Override
15     protected void onCreate(Bundle savedInstanceState) {
16         super.onCreate(savedInstanceState);
17         setContentView(R.layout.activity_main);
18     }
19 
20 //点击按钮生成private文件
21 public void click1(View v){
22      try {
23         FileOutputStream fos=openFileOutput("private.txt",MODE_PRIVATE);
24         fos.write("private".getBytes());
25         fos.close();
26     } catch (Exception e) {
27         // TODO Auto-generated catch block
28         e.printStackTrace();
29     }
30 }
31     
32 //点击按钮生成append文件
33 public void click2(View v){
34      try {
35         FileOutputStream fos=openFileOutput("append.txt",MODE_APPEND);
36         fos.write("append".getBytes());
37         fos.close();
38     } catch (Exception e) {
39         // TODO Auto-generated catch block
40         e.printStackTrace();
41     }
42 }
43 //点击按钮生成read文件
44 public void click3(View v){
45      try {
46         FileOutputStream fos=openFileOutput("read.txt",MODE_WORLD_READABLE);
47         fos.write("read".getBytes());
48         fos.close();
49     } catch (Exception e) {
50         // TODO Auto-generated catch block
51         e.printStackTrace();
52     }
53 }
54 //点击按钮生成write文件
55 public void click4(View v){
56      try {
57         FileOutputStream fos=openFileOutput("write.txt",MODE_WORLD_WRITEABLE);
58         fos.write("write".getBytes());
59         fos.close();
60     } catch (Exception e) {
61         // TODO Auto-generated catch block
62         e.printStackTrace();
63     }
64 }
65 
66 
67 }

activity_main.xml

 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical"
 6     tools:context=".MainActivity" >
 7 
 8     <Button
 9         android:layout_width="wrap_content"
10         android:layout_height="wrap_content"
11         android:onClick="click1"
12         android:text="private" />
13 
14     <Button
15         android:layout_width="wrap_content"
16         android:layout_height="wrap_content"
17         android:onClick="click2"
18         android:text="append" />
19 
20     <Button
21         android:layout_width="wrap_content"
22         android:layout_height="wrap_content"
23         android:onClick="click3"
24         android:text="read" />
25 
26     <Button
27         android:layout_width="wrap_content"
28         android:layout_height="wrap_content"
29         android:onClick="click4"
30         android:text="write" />
31 
32 </LinearLayout>

结果: