1 package com.example.wxy.kcsj2;
 2 
 3 import android.content.Context;
 4 import android.database.sqlite.SQLiteDatabase;
 5 import android.os.Environment;
 6 import android.util.Log;
 7 
 8 import java.io.File;
 9 import java.io.FileNotFoundException;
10 import java.io.FileOutputStream;
11 import java.io.IOException;
12 import java.io.InputStream;
13 
14 public class DataBaseHelper {
15     private final int BUFFER_SIZE = 400000;
16     public static final String DB_NAME = "student.db3"; // 保存的数据库文件名
17     public static final String PACKAGE_NAME = "com.example.wxy.kcsj2";// 应用的包名
18     public static final String DB_PATH = "/data" + Environment.getDataDirectory().getAbsolutePath() + "/"
19             + PACKAGE_NAME + "/databases/"; // 在手机里存放数据库的位置
20     //sdcard的路径(在android 4.4中不好使，文件成功创建是在手机的)
21     //public static final String DB_PATH = Environment.getExternalStorageDirectory().getAbsolutePath()+"/student";
22     private SQLiteDatabase database;
23     private Context context;
24 
25     public SQLiteDatabase getDatabase() {
26         return database;
27     }
28 
29     public void setDatabase(SQLiteDatabase database) {
30         this.database = database;
31     }
32 
33     public DataBaseHelper(Context context) {
34         this.context = context;
35     }
36 
37     public void openDatabase() {
38         System.out.println(DB_PATH + "/" + DB_NAME);
39         System.out.println("打开数据库");
40         this.database = this.openDatabase(DB_PATH + "/" + DB_NAME);
41     }
42 
43     public SQLiteDatabase openDatabase(String dbfile) {
44         try {
45             File myDataPath = new File(DB_PATH);
46             if (!myDataPath.exists()) {
47                 myDataPath.mkdirs();// 如果没有这个目录,则创建
48                 System.out.println("目录,创建");
49             }
50             dbfile = myDataPath + "/" + DB_NAME;
51             if (!(new File(dbfile).exists())) {// 判断数据库文件是否存在，若不存在则执行导入，否则直接打开数据库
52                 InputStream is = context.getResources().openRawResource(R.raw.student); // 欲导入的数据库
53                 FileOutputStream fos = new FileOutputStream(dbfile);
54                 byte[] buffer = new byte[BUFFER_SIZE];
55                 int count = 0;
56                 while ((count = is.read(buffer)) > 0) {
57                     fos.write(buffer, 0, count);
58                 }
59                 fos.close();
60                 is.close();
61             }
62             SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(dbfile,
63                     null);
64             return db;
65         } catch (FileNotFoundException e) {
66             Log.e("Database", "File not found");
67             System.out.println("文件啊没找到");
68             e.printStackTrace();
69         } catch (IOException e) {
70             Log.e("Database", "IO exception");
71             System.out.println("io输入输出错误");
72             e.printStackTrace();
73         }
74         return null;
75     }
76 
77     public void closeDatabase() {
78         this.database.close();
79         System.out.println("关闭数据库");
80     }
81 }