Android学习笔记之数据的Sdcard存储方法及操作sdcard的工具类

FileService.java也就是操作sdcard的工具类：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
package com.example.data_storage_sdcard.file;
 
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
 
import android.os.Environment;
 
/**
 * sdcard的存在于上下文无关
 *
 * @author piaodangdehun
 *
 */
public class FileService {
 
    /*
     * 存放在sdcard的根目录
     */
    public boolean saveFileToSdcardRoot(String fileName, byte[] data) {
        boolean flag = false;
        /*
         * 先判断sdcard的状态，是否存在
         */
        String state = Environment.getExternalStorageState();
        FileOutputStream outputStream = null;
        File rootFile = Environment.getExternalStorageDirectory(); // 获得sdcard的根路径
        /*
         * 表示sdcard挂载在手机上，并且可以读写
         */
        if (state.equals(Environment.MEDIA_MOUNTED)) {
            File file = new File(rootFile, fileName);
            try {
                outputStream = new FileOutputStream(file);
                try {
                    outputStream.write(data, 0, data.length);
                    flag = true;
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } finally {
                if (outputStream != null) {
                    try {
                        outputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
        return flag;
    }
 
    /*
     * 存放在sdcard下自定义的目录
     */
    public boolean saveFileToSdcardDir(String fileName, byte[] data) {
        boolean flag = false;
        /*
         * 先判断sdcard的状态，是否存在
         */
        String state = Environment.getExternalStorageState();
        FileOutputStream outputStream = null;
        File rootFile = Environment.getExternalStorageDirectory(); // 获得sdcard的根路径
        /*
         * 表示sdcard挂载在手机上，并且可以读写
         */
        if (state.equals(Environment.MEDIA_MOUNTED)) {
            File file = new File(rootFile.getAbsoluteFile() + /txt);
            if (!file.exists()) {
                file.mkdirs();
            }
            try {
                outputStream = new FileOutputStream(new File(file, fileName));
                try {
                    outputStream.write(data, 0, data.length);
                    flag = true;
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } finally {
                if (outputStream != null) {
                    try {
                        outputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
        return flag;
    }
 
    /*
     * 用于读取sdcard的数据
     */
    public String readContextFromSdcard(String fileName) {
 
        String state = Environment.getExternalStorageState();
        File rooFile = Environment.getExternalStorageDirectory(); // 获得sdcard的目录
 
        FileInputStream inputStream = null;// 用于度取数据的流
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); // 用于存放独处的数据
 
        if (state.equals(Environment.MEDIA_MOUNTED)) {
            File file = new File(rooFile.getAbsoluteFile() + /txt/);// 在sdcard目录下创建一个txt目录
            File file2 = new File(file, fileName);
            int len = 0;
            byte[] data = new byte[1024];
            if (file2.exists()) {
                try {
                    inputStream = new FileInputStream(file2);
                    try {
                        while ((len = inputStream.read(data)) != -1) {
                            outputStream.write(data, 0, data.length);
                        }
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    return new String(outputStream.toByteArray());
                } catch (FileNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } finally {
                    if (outputStream != null) {
                        try {
                            outputStream.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        }
        return null;
    }
 
    /**
     * 对文件进行分类的保存到固定的文件中去
     *
     * @param fileName
     * @param data
     */
    public void saveFileToSdcardBySuff(String fileName, byte[] data) {
        // File file = Environment.getExternalStoragePublicDirectory();
        // 保存文件的目录
        File file = null;
        if (Environment.getExternalStorageState().equals(
                Environment.MEDIA_MOUNTED)) {
 
            /*
             * 将不同的文件放入到不同的类别中
             */
            if (fileName.endsWith(.mp3)) {
                file = Environment
                        .getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC);
            } else if (fileName.endsWith(.jpg) || fileName.endsWith(.png)
                    || fileName.endsWith(.gif)) {
                file = Environment
                        .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
            } else if (fileName.endsWith(.mp4) || fileName.endsWith(.avi)
                    || fileName.endsWith(.3gp)) {
                file = Environment
                        .getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES);
            } else {
                file = Environment
                        .getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
            }
            FileOutputStream outputStream = null;
            try {
                outputStream = new FileOutputStream(new File(file, fileName));
                try {
                    outputStream.write(data, 0, data.length);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } finally {
                if (outputStream != null) {
                    try {
                        outputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
    }
 
    /*
     * 删除一个文件
     */
    public boolean deleteFileFromSdcard(String folder, String fileName) {
        boolean flag = false;
        File file = Environment.getExternalStorageDirectory();
        if (Environment.getExternalStorageState().equals(
                Environment.MEDIA_MOUNTED)) {
            File exitFile = new File(file.getAbsoluteFile() + / + folder);
            if (exitFile.exists()) {
                exitFile.delete();
            }
        }
        return flag;
    }
}


HttpUtils.java访问网络的

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
package com.example.data_storage_sdcard.http;
 
import java.io.IOException;
 
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
 
public class HttpUtils {
    /*
     *
     */
    public static byte[] getImage(String path) {
        byte[] data = null;
        HttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost(path);
        try {
            HttpResponse response = httpClient.execute(httpPost);
            if (response.getStatusLine().getStatusCode() == 200) {
                data = EntityUtils.toByteArray(response.getEntity());
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            httpClient.getConnectionManager().shutdown();
        }
 
        return data;
 
    }
}

ImageCache.java将文件放到cache中的：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
package com.example.data_storage_sdcard.img;
 
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
 
import android.os.Environment;
 
public class ImageCache {
 
    public static  String saveImageCache(String fileName, byte[] data) {
        File file = Environment.getExternalStorageDirectory(); // 根目录
        FileOutputStream outputStream = null;
        if (Environment.getExternalStorageState().equals(
                Environment.MEDIA_MOUNTED)) {
            try {
                outputStream = new FileOutputStream(new File(file, fileName));
                outputStream.write(data, 0, data.length);
 
                return file.getAbsolutePath() + / + fileName;
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                if (outputStream != null) {
                    try {
                        outputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
        return null;
    }
}


MainActivity.java

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
package com.example.data_storage_sdcard;
 
import android.app.Activity;
import android.app.ProgressDialog;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
 
import com.example.data_storage_sdcard.http.HttpUtils;
import com.example.data_storage_sdcard.img.ImageCache;
 
public class MainActivity extends Activity {
    private Button button;
    private ImageView imageView;
    private ProgressDialog progressDialog;
 
    private String imageName;
 
    private final String pathString = http://www.baidu.com/img/bd_logo1.png;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = (Button) this.findViewById(R.id.button1);
        imageView = (ImageView) this.findViewById(R.id.imageView1);
 
        progressDialog = new ProgressDialog(this);
        progressDialog.setTitle(下载提示);
        progressDialog.setMessage(load...);
        button.setOnClickListener(new OnClickListener() {
 
            @Override
            public void onClick(View v) {
                new MyTask().execute(pathString);
            }
        });
    }
 
    class MyTask extends AsyncTask<string,> {
 
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            progressDialog.show();
        }
 
        @Override
        protected byte[] doInBackground(String... params) {
            String name = params[0];
            imageName = name
                    .substring(name.lastIndexOf(/) + 1, name.length());
            return HttpUtils.getImage(params[0]);
        }
 
        @Override
        protected void onProgressUpdate(Void... values) {
            super.onProgressUpdate(values);
        }
 
        @Override
        protected void onPostExecute(byte[] result) {
            super.onPostExecute(result);
            if (result != null) {
                Bitmap bm = BitmapFactory.decodeByteArray(result, 0,
                        result.length);
                imageView.setImageBitmap(bm);
                ImageCache.saveImageCache(, result);
            } else {
                imageView.setImageResource(R.drawable.ic_launcher);
            }
            progressDialog.dismiss();
        }
    }
 
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
 
}
</string,>


测试类：

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
package com.example.data_storage_sdcard;
 
import java.io.FileWriter;
 
import com.example.data_storage_sdcard.file.FileService;
 
import android.nfc.Tag;
import android.test.AndroidTestCase;
import android.util.Log;
 
public class MyTest extends AndroidTestCase {
 
    public void saveFileToSdcardTest() {
        FileService fileService = new FileService();
 
        fileService.saveFileToSdcardRoot(aa.txt,
                jkhdsfjkhdskjfhdsjf.getBytes());
    }
 
    public void saveFileToSdcardDir() {
        FileService fileService = new FileService();
 
        fileService.saveFileToSdcardRoot(aa.txt,
                jkhdsfjkhdskjfhdsjf.getBytes());
    }
 
    public void readContextFromSdcardTest() {
        FileService fileService = new FileService();
        String msg = fileService.readContextFromSdcard(aa.txt);
        System.err.println(--> + msg);
    }
 
    public void saveFileToSdcardBySuffTest() {
        FileService fileService = new FileService();
        fileService.saveFileToSdcardBySuff(aa.avi,
                asdfkajsgdhagsdfhdgsf.getBytes());
    }
 
    public void delFile() {
        FileService fileService = new FileService();
        boolean flag = fileService.deleteFileFromSdcard(txt, aa.txt);
    }
}


需要在请单位按中加入访问网络的权限、操作sdcard的权限、测试的权限

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
<!--?xml version=1.0 encoding=utf-8?-->
<manifest android:versioncode="1" android:versionname="1.0" package="com.example.data_storage_sdcard" xmlns:android="http://schemas.android.com/apk/res/android">
 
    <uses-sdk android:minsdkversion="8" android:targetsdkversion="18">
 
    <instrumentation android:name="android.test.InstrumentationTestRunner" android:targetpackage="com.example.data_storage_sdcard">
    </instrumentation>
    <!-- 添加访问sdcard的权限 -->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE">
    <!-- 添加访问网络的权限 -->
    <uses-permission android:name="android.permission.INTERNET">
 
     
        <uses-library android:name="android.test.runner">
 
         
            <intent-filter>
                 
 
                <category android:name="android.intent.category.LAUNCHER">
            </category></action></intent-filter>
        </activity>
 
        <uses-library>
        </uses-library>
    </uses-library></application>
 
</uses-permission></uses-permission></uses-sdk></manifest>
 

结伴旅游,一个免费的交友网站：www.jieberu.com

推推族，免费得门票，游景区：www.tuituizu.com

【推广】 免费学中医，健康全家人
原文地址：https://www.cnblogs.com/rabbit-bunny/p/4238064.html