一. 如果手机是6.0以上的
1. 要初始化一下权限
private void initPermission() {
String permissions[] = {
Manifest.permission.INTERNET,
Manifest.permission.ACCESS_NETWORK_STATE,
Manifest.permission.MODIFY_AUDIO_SETTINGS,
Manifest.permission.WRITE_SETTINGS,
Manifest.permission.READ_PHONE_STATE,
Manifest.permission.ACCESS_WIFI_STATE,
Manifest.permission.CHANGE_WIFI_STATE,
Manifest.permission.SYSTEM_ALERT_WINDOW,
Manifest.permission.CAMERA,
Manifest.permission.MODIFY_AUDIO_SETTINGS,
Manifest.permission.RECORD_AUDIO,
Manifest.permission.WAKE_LOCK,
Manifest.permission.WRITE_EXTERNAL_STORAGE,
Manifest.permission.READ_EXTERNAL_STORAGE
};
ArrayList toApplyList =new ArrayList();
for (String perm : permissions) {
if (PackageManager.PERMISSION_GRANTED != ContextCompat.checkSelfPermission(this, perm)) {
toApplyList.add(perm);
//进入到这里代表没有权限.
}
}
String tmpList[] =new String[toApplyList.size()];
if (!toApplyList.isEmpty()) {
ActivityCompat.requestPermissions(this, toApplyList.toArray(tmpList),123);
}
}
2. 回调下面的方法
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions,int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode ==REQUEST_EXTERNAL_STORAGE) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
MyLogcat.showTestLog(TAG,"授权成功");
}else {
MyLogcat.showTestLog(TAG,"授权失败,请去设置打开权限");
}
}
}
如果是继承SQLiteOpenHelper，按照下面的方式
SDCardDataBaseHelper.java
public class SDCardDataBaseHelper2extends SQLiteOpenHelper {
private static final StringTAG = SDCardDataBaseHelper2.class.getSimpleName();
private ContextmContext;
//db文件路径,保存在sd卡中
public static final StringDB_PATH = Environment.getExternalStorageDirectory().getPath()
+ File.separator +"mydata" + File.separator;
//数据库名
public static StringDB_NAME;
//数据库版本
public static final int VERSION =1;
private static String getMyDatabaseName(String name) {
String databasename = name;
boolean isSdcardEnable =false;
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {//SDCard是否插入
isSdcardEnable =true;
}
MyLogcat.showTestLog(TAG,"isSdcardEnable = " + isSdcardEnable);
String dbPath =null;
if (isSdcardEnable) {
dbPath = Environment.getExternalStorageDirectory().getAbsolutePath() +"/Finance/database/";
}else {//未插入SDCard，建在内存中
}
File dbp =new File(dbPath);
if (!dbp.exists()) {
dbp.mkdirs();
}
MyLogcat.showTestLog(TAG,"dbPath = " + dbPath);
databasename = dbPath + databasename;
// SQLiteDatabase database=SQLiteDatabase.openOrCreateDatabase(databasename,null);
return databasename;
}
public SDCardDataBaseHelper2(Context context) {
super(context,getMyDatabaseName("test.db"),null,VERSION);//*; dbname;*;dbversion
this.mContext = context;
}
@Override
public void onCreate(SQLiteDatabase db) {
System.out.println("create");
//建表
System.out.println("create over");
}
@Override
public void onUpgrade(SQLiteDatabase db,int oldVersion,int newVersion) {
System.out.println("update");
// db.execSQL("ALTER TABLE person ADD phone VARCHAR(12) NULL");
System.out.println("update over");
}
下面的是在Activity中调用：
//数据库
SDCardDataBaseHelper2 mMysql;
SQLiteDatabase mDataBase;
//获取当前数据库
mMysql =new SDCardDataBaseHelper2(this);
mDataBase = mMysql.getReadableDatabase();
如果是继承OrmLiteSqliteOpenHelper，按照下面的方式
public class SDCardDataBaseHelperextends OrmLiteSqliteOpenHelper {
private static final StringTAG = SDCardDataBaseHelper.class.getSimpleName();
public static StringDB_NAME;
/**
* helloDao 没张表对应一个
*/
private DaohelloDao;
//db文件路径,保存在sd卡中
// public static final String DB_PATH = Environment.getExternalStorageDirectory().getPath()
public static final StringDB_PATH ="/sdcard"
+ File.separator +"db" + File.separator;
static{
//判断sd卡是否正常挂载
if(! Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
DB_NAME ="status.db";//sd卡未正常挂载,则数据库还保存在默认位置
}else{
DB_NAME =DB_PATH +"status.db";
File dbFolder =new File(DB_PATH);
// 目录不存在则自动创建目录
if (!dbFolder.exists()){
dbFolder.mkdirs();
}
}
}
public SDCardDataBaseHelper(Context context) {
super(context,DB_NAME,null, Constants.DB_VERSION);
MyLogcat.showTestLog(TAG,"DB_NAME = " +DB_NAME);
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase, ConnectionSource connectionSource) {
MyLogcat.showTestLog(TAG,"onCreate start");
try {
TableUtils.createTable(connectionSource, Hello.class);
}catch (SQLException e) {
e.printStackTrace();
}
MyLogcat.showTestLog(TAG,"onCreate end");
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, ConnectionSource connectionSource,int i,int i1) {
}
/**
* 单例获取该Helper
* 1.先把构造函数私有化
* 2.对外提供一个静态方法
* 3.在方法中判断如果已经存在就不再创建，如果不存在再创建这样就永远只有一个DataHelper对象
* 4.为了线程安全，需要再方法钱提供一个线程安全关键字synchronized
*/
private static SDCardDataBaseHelpersdCardDataBaseHelper;
public static synchronized SDCardDataBaseHelper getHeper(Context context) {
if (sdCardDataBaseHelper ==null) {
synchronized (SDCardDataBaseHelper.class){
if (sdCardDataBaseHelper ==null) {
sdCardDataBaseHelper =new SDCardDataBaseHelper(context);
}
}
}
return sdCardDataBaseHelper;
}
public Dao getHelloDao()throws SQLException {
if (helloDao ==null) {
helloDao = getDao(Hello.class);
}
MyLogcat.showTestLog(TAG,"getHelloDao()");
return helloDao;
}
public synchronized void clearData(Class clase) {
try {
TableUtils.clearTable(connectionSource, clase);
}catch (SQLException e) {
e.printStackTrace();
}
}
@Override
public synchronized SQLiteDatabase getWritableDatabase() {
return SQLiteDatabase.openDatabase(DB_NAME,null,
SQLiteDatabase.OPEN_READWRITE);
}
public synchronized SQLiteDatabase getReadableDatabase() {
return SQLiteDatabase.openDatabase(DB_NAME,null,
SQLiteDatabase.OPEN_READONLY);
}
}
在Activity中调用
SDCardDataBaseHelper.getHeper(this);
MyLogcat.showTestLog(TAG,"new File(\"/sdcard/db\").listFiles().length = " +new File("/sdcard/db").listFiles().length);
if (new File("/sdcard/db").listFiles().length <=0) {
SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(
SDCardDataBaseHelper.DB_NAME,null);
SDCardDataBaseHelper orm =new SDCardDataBaseHelper(this);
orm.onCreate(db);
db.close();
}
HelloDao helloDao =new HelloDao(this);
helloDao.add(new Hello("sdcard","male",23));