Android-sqlite数据库存取图片信息
看到网上很多人都用下面的几种方式保存图片到数据据，感觉蛮靠谱的，之前我转载的那些方法貌似都不管用（也可能是我不会用），今晚先收藏，明天或者有空的时候再试试下面的方法，先收藏：
更新
SQLiteDatabase db;
String args[] = {id};
ContentValues cv = new ContentValues();
cv.put("android123", id);
Cursor c = db.rawQuery("SELECT * FROM table WHERE android123=?", args); 执行本地SQL语句查询
if (c.getCount() != 0) {
//dosomething
ContentValues cv = new ContentValues();
cv.put("android123","cwj");
db.insert("table", "android123", cv); //插入数据
String args[] = {id};
ContentValues cv2= new ContentValues();
cv2.put("android123", id);
db.delete("table", "android123=?", args); //删除数据
}
网上第一个版本：
一、数据库创建和存取方法：
在数据库创建时，图片字段的数据类型存储为 BLOB数据库插入操作
public void onCreate(SQLiteDatabase db)
{
String sql = "create table " + TB_NAME + " ( " + ID + " integer primary key , " + IMAGE + " BLOB ) ";
db.execSQL(sql);
}
将图片一字节形式存储数据库读取操作
public long insert(byte[] img)
{
SQLiteDatabase db = getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(IMAGE, img);
long result = db.insert(TB_NAME, null, cv);
return result;
}
得到的图片是Bitmap类型,参数position 点击图片在ListView、GridView等内的位置 ，可根据需要编写代码二
public Bitmap getBmp(int position)
{
SQLiteDatabase db = getReadableDatabase();
Cursor cursor = select(TB_NAME);
cursor.moveToPosition(position);
byte[] in = cursor.getBlob(cursor.getColumnIndex(IMAGE));
Bitmap bmpout = BitmapFactory.decodeByteArray(in, 0, in.length);
return bmpout;
}
二、将图片转化为 byte[]//参数id为图片资源 （R.drawable.img）
public byte[] img(int id)
{
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Bitmap bitmap = ((BitmapDrawable) getResources().getDrawable(id)).getBitmap();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
return baos.toByteArray();
db.execSQL(sql);
ContentValues cv = new ContentValues();
cv.put(IMAGE, img);
long result = db.insert(TB_NAME, null, cv);
return result;
Cursor cursor = select(TB_NAME);
cursor.moveToPosition(position);
byte[] in = cursor.getBlob(cursor.getColumnIndex(IMAGE));
Bitmap bmpout = BitmapFactory.decodeByteArray(in, 0, in.length);
return bmpout;
Bitmap bitmap = ((BitmapDrawable) getResources().getDrawable(id)).getBitmap();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
return baos.toByteArray();
}
可惜我想要的是能一连串的查询，查询的时候有文字和图片一起都查到， 上面这种暂时不是我想要的，下面这个人的感觉蛮可以，他应该是验证过的， 应该是我想要了的吧，
网上第二个版本
转自http://blog.sina.com.cn/s/blog_539070ad0100nesa.html
import java.io.ByteArrayOutputStream;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.util.Log;
// 数据操作类
public class testSeedDB {
privateContext mContext= null;
privatetestDBHelper mDBHelper= null;
privateSQLiteDatabase mTestDatabase= null;
privatestatic finalString DATABASE_NAME= "DHSeedData.db";
privatestatic finalint DATABASE_VERSION= 1;
privatestatic finalString TABLE_SEED= "TBseed";
privatestatic finalString TABLE_INFO= "TBinfo";
// 构造函数，一个引用类的Context作为参数
publictestSeedDB(Context context){
mContext = context;
}
// 打开数据库
publicvoid open(){
mDBHelper= newtestDBHelper(mContext,DATABASE_NAME,null,DATABASE_VERSION);
mTestDatabase= mDBHelper.getWritableDatabase();
Log.i("testSeedDB","open");
}
// Close the database
publicvoid close(){
mDBHelper.close();
}
publicvoid CreateSeedTable() {
// 创建数据表是先删除以前的，以免出错
String sql ="drop table "+TABLE_SEED;
try{
mTestDatabase.execSQL(sql);
} catch(SQLException e) {
}
// second create table
sql ="CREATE TABLE IF NOT EXISTS " + TABLE_SEED
+" (ID INTEGER PRIMARY KEY, ToyID INTEGER,ToySeed BLOB,ToyMemo TEXT);";
try {
mTestDatabase.execSQL(sql);
}catch (SQLException ex) {
}
Log.i("testSeedDB","CreateSeedTable");
}
publicvoid CreateInfoTable() {
// first delete old table
String sql = "drop table"+ TABLE_INFO;
try{
mTestDatabase.execSQL(sql);
} catch(SQLException e) {
}
// second create table
sql = "CREATE TABLE IF NOT EXISTS " + TABLE_INFO
+" (ToyID INTEGER PRIMARY KEY,ToySeed BLOB,ToyMemo TEXT not null);";
try {
mTestDatabase.execSQL(sql);
}catch (SQLException ex) {
}
}
publicvoid CleanSeedTable() {
try {
mTestDatabase.delete(TABLE_SEED,null,null);
}catch (SQLException e) {
}
Log.i("testSeedDB","ClearSeedTable");
}
publicvoid insertSeedItem(longToyID, byte[]ToySeed) {
String sqlstr ="insert into " +TABLE_SEED + " (ToyID, ToySeed,ToyMemo) values (?,?,?);";
Object[] args =new Object[]{ToyID,ToySeed,null};
try{
mTestDatabase.execSQL(sqlstr,args);
}catch (SQLException ex) {
}
Log.i("testSeedDB","insertSeedItem");
}
publicbyte[] GetSeedItem(longToyID) {
Cursor cur;
byte[] strSeed =null;
String col[] = {"ToyID","ToySeed" ,"ToyMemo"};
String strToy ="ToyID=" + new Integer((int) ToyID).toString();
try{
cur =mTestDatabase.query(TABLE_SEED, col, strToy,null,null,null,null);
cur.moveToFirst();
strSeed = cur.getBlob(1);
}catch (SQLException ex) {
}
if (cur !=null) cur.close;
Log.i("testSeedDB", strToy);
return strSeed;
}
// 数据操作的基础类，作为数据操作的内嵌子类
publicclass testDBHelperextends SQLiteOpenHelper {
publictestDBHelper(Context context, String name, CursorFactory factory,
int version) {
super(context, name, factory, version);
// TODOAuto-generated constructor stub
}
@Override
publicvoidonCreate(SQLiteDatabase db) {
// TODOAuto-generated method stub
}
@Override
publicvoidonUpgrade(SQLiteDatabase db,int oldVersion, int newVersion) {
// TODOAuto-generated method stub
}
} // end of testDBHelper
}
// 读文件到 BYTE 来自网上未验证
//http://www.a3gs.com/BookViews.asp?InfoID=2865&ClassID=935
导入包：
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
实现代码：
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
try{
getBytesFromFile(new File("C:\\aaa.txt"));
}catch(IOException e){
System.out.println("IOException");
}
}
// 返回一个byte数组
public static byte[] getBytesFromFile(File file) throws IOException {
InputStream is = new FileInputStream(file);
// 获取文件大小
long length = file.length();
if (length > Integer.MAX_VALUE) {
// 文件太大，无法读取
throw new IOException("File is to large "+file.getName());
}
// 创建一个数据来保存文件数据
byte[] bytes = new byte[(int)length];
// 读取数据到byte数组中
int offset = 0;
int numRead = 0;
while (offset < bytes.length
&& (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
offset += numRead;
}
// 确保所有数据均被读取
if (offset < bytes.length) {
throw new IOException("Could not completely read file "+file.getName());
}
// Close the input stream and return bytes
is.close();
return bytes;
}
}