SQLiteCopy

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import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import com.bwie.day2sqlite.R;
import com.hgz.day6sqlite.dao.Dao;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener {

    private Dao dao;

   @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btnAdd = (Button) findViewById(R.id.btnAdd);
        Button btnUpdate = (Button) findViewById(R.id.btnUpdate);
        Button btnDelete = (Button) findViewById(R.id.btnDelete);
        Button btnFindAll = (Button) findViewById(R.id.btnFindAll);
        Button btnFindCondition = (Button) findViewById(R.id.btnFindCondition);
        Button btnCopy = (Button) findViewById(R.id.btnCopy);


        btnAdd.setOnClickListener(this);
        btnUpdate.setOnClickListener(this);
        btnDelete.setOnClickListener(this);
        btnFindAll.setOnClickListener(this);
        btnFindCondition.setOnClickListener(this);

btnCopy.setOnClickListener(this);

//实例化Dao类

        dao = new Dao(this);
    }

   @Override
   public void onClick(View v) {
       switch (v.getId()) {
       case R.id.btnAdd:
           dao.add("heguozhong", "130");
           break;
       case R.id.btnUpdate:
           dao.update("heguo", "1111", 5);
           break;
       case R.id.btnDelete:
           dao.delete(1);
           break;
       case R.id.btnFindAll:
           String string = dao.findAll();
           Toast.makeText(MainActivity.this, string, Toast.LENGTH_SHORT).show();
           break;
       case R.id.btnFindCondition:
           String str = dao.findConditon(5);
           Toast.makeText(MainActivity.this, str, Toast.LENGTH_SHORT).show();
           break;
       case R.id.btnCopy:
           copyDatabase();
           break;
       default:
           break;
       }
   }
   //备份数据库
   @SuppressWarnings("resource")
   private void copyDatabase() {
       //关联到需要备份的数据库
       File file = new File("/data/data/"+getPackageName()+"/databases","user.db");
       System.out.println("文件目录 : "+file.getPath());
       try {
           FileInputStream is = new FileInputStream(file);

           //备份数据库到那个目的地(位置),sdcard
           //getExternalStorageDirectory() 拿到的是一个sdcrad根目录
           File file2 = new File(Environment.getExternalStorageDirectory(), "copyUser.db");
           System.out.println("路径 : "+Environment.getExternalStorageDirectory().getPath());
           FileOutputStream os = new FileOutputStream(file2);
           byte[] buffer=new byte[1024];
           int length=0;
           while ((length=is.read(buffer))!=-1) {
               os.write(buffer, 0, length);
           }
           is.close();
           os.close();
           Toast.makeText(this, "备份数据库成功", 0).show();
       } catch (Exception e) {
           e.printStackTrace();
           Toast.makeText(this, "备份数据库失败", 0).show();
       }
   }

}

//SQLite类

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;

public class SQLite extends SQLiteOpenHelper {

   public SQLite(Context context) {
       // context 上下文
       // name 数据库的名字
       // factory 游标工厂填null 代表的是使用系统自带的游标工厂
       // version 数据库的版本必须 >= 1
       super(context, "user.db", null, 1);
   }
   /**
   * 这个方法是数据库第一次被创建的时候会被调用,只会执行一次
   * 通常用于初始化表结构
   *
   */
   @Override
   public void onCreate(SQLiteDatabase db) {
       db.execSQL("create table user(_id Integer primary key autoincrement,name varchar(20),phone varchar(20))");
   }

   @Override
   public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

   }

}

//Dao类

import com.hgz.day6sqlite.SQLite;
import android.R.integer;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

public class Dao {
   private SQLiteDatabase db;

   public Dao(Context context) {
       SQLite sqLite = new SQLite(context);
       // 得到操作数据库的实例对象
       db = sqLite.getWritableDatabase();
   }

   public void add(String name, String phone) {
       db.execSQL("insert into user(name,phone) values(?,?)", new Object[] {
               name, phone });
   }

   public void update(String name, String phone, int id) {
       db.execSQL("update user set name=?,phone=? where _id=?", new Object[] {
               name, phone, String.valueOf(id) });
   }

   public void delete(int id) {
       db.execSQL("delete from user where _id=?",
               new Object[] { String.valueOf(id) });
   }

   public String findAll() {
       Cursor cursor = db.rawQuery("select *from user", null);
       // 参数1：查询的sql语句
       // 参数2：查询的条件
       // cursor.moveToFirst();//移动第一行
       // cursor.moveToLast();//移动到最后一行
       // cursor.moveToPrevious();//移动到前一行
       // cursor.moveToPosition(position);//移动到指定的行
       // cursor.moveToNext();//移动到下一行
       // 创建一个容器
       StringBuffer sb = new StringBuffer();
       while (cursor.moveToNext()) {
           String name = cursor.getString(cursor.getColumnIndex("name"));
           String phone = cursor.getString(cursor.getColumnIndex("phone"));
           sb.append("姓名：" + name + "       电话：" + phone + "\n");
       }
       return sb.toString();
   }

   public String findConditon(int id) {
       Cursor cursor = db.rawQuery("select * from user where _id=?",
               new String[] { String.valueOf(id) });
       String string = "";
       while (cursor.moveToNext()) {
           String name = cursor.getString(cursor.getColumnIndex("name"));
           String phone = cursor.getString(cursor.getColumnIndex("phone"));
           string = "姓名：" + name + "   电话:" + phone + "\n";
       }
       return string;
   }

}

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