1 package com.example.administrator.myapplication.activity;
2
3 import android.os.Bundle;
4 import android.os.Environment;
5 import android.support.v7.app.AppCompatActivity;
6 import android.view.View;
7 import android.widget.Button;
8 import android.widget.Toast;
9
10 import com.example.administrator.myapplication.R;
11 import com.example.administrator.myapplication.entity.SDCard;
12
13 import java.io.File;
14 import java.io.FileInputStream;
15 import java.io.FileOutputStream;
16 import java.io.IOException;
17 import java.io.ObjectInputStream;
18 import java.io.ObjectOutputStream;
19
20 public class SdCardActivity extends AppCompatActivity {
21 Button writeBtn;
22 Button readBtn;
23 @Override
24 protected void onCreate(Bundle savedInstanceState) {
25 super.onCreate(savedInstanceState);
26 setContentView(R.layout.activity_sd_card);
27 inno();
28 }
29
30 private void inno() {
31 writeBtn = (Button) findViewById(R.id.write);
32 writeBtn.setOnClickListener(new View.OnClickListener() {
33 @Override
34 public void onClick(View v) {
35 WriteToSD();
36 }
37 });
38 readBtn = (Button) findViewById(R.id.read);
39 readBtn.setOnClickListener(new View.OnClickListener() {
40 @Override
41 public void onClick(View v) {
42 ReadFormSD();
43 }
44 });
45 }
46
47 //保存文件到SD卡
48 private void WriteToSD(){
49 ObjectOutputStream oos = null;
50 //Environment.getExternalStorageState获取外部存储的状态
51 String state = Environment.getExternalStorageState();
52 //外部存储正常 如果SD卡存在
53 if (state.equals(Environment.MEDIA_MOUNTED)){
54 //获取外部存储的根路径
55 File root = Environment.getExternalStorageDirectory();
56 //在SD卡下创建新的文件夹
57 File TargetDir = new File(root,super.getPackageName());
58 //若不存在，创建文件夹
59 if (!TargetDir.exists()){
60 TargetDir.mkdir();
61 }
62 try {
63 oos = new ObjectOutputStream(new FileOutputStream(new File(TargetDir+"SDCard.txt")));
64 SDCard sdCard = new SDCard("小宝","是大二的!");
65 oos.writeObject(sdCard);
66 Toast.makeText(getApplication(),"写入SD卡成功！",Toast.LENGTH_SHORT).show();
67 } catch (IOException e) {
68 e.printStackTrace();
69 }finally {
70 try {
71 oos.flush();
72 oos.close();
73 } catch (IOException e) {
74 e.printStackTrace();
75 }
76 }
77 }else {
78 Toast.makeText(getApplication(),"没有找到SD卡",Toast.LENGTH_SHORT).show();
79 }
80 }
81
82 //从SD卡读取文件
83 private void ReadFormSD(){
84 ObjectInputStream ois = null;
85 String state = Environment.getExternalStorageState();
86 if (state.equals(Environment.MEDIA_MOUNTED)){
87 File root = Environment.getExternalStorageDirectory();
88 File TargetDir = new File(root,super.getPackageName());
89 if (TargetDir.exists()){
90 try {
91 ois = new ObjectInputStream(new FileInputStream(new File(TargetDir+"SDCard.txt")));
92 SDCard sdCard = (SDCard) ois.readObject();
93 Toast.makeText(SdCardActivity.this,sdCard.getName()+" "+sdCard.getIntroduce(),Toast.LENGTH_SHORT).show();
94 } catch (IOException e) {
95 e.printStackTrace();
96 } catch (ClassNotFoundException e) {
97 e.printStackTrace();
98 }finally {
99 try {
100 ois.close();
101 } catch (IOException e) {
102 e.printStackTrace();
103 }
104 }
105 }
106 }
107 }
108 }
