一些自己常用的工具类

1.SharedPreferencesUtils  引导页一般用来保存打开记录

package myapplication.com.myapp.Utils;

import android.content.Context;
import android.content.SharedPreferences;

/**
 * Created by Administrator on 2016/8/9.
 */
public class SharedPreferencesUtils {


    private  static String NAME="share_data";
    public static  void  setParam(Context context, String key, Object object){
        SharedPreferences p=context.getSharedPreferences(NAME,Context.MODE_APPEND);
        String type=object.getClass().getSimpleName();
        SharedPreferences.Editor editor=p.edit();
        if(type.equals("String")){
            editor.putString(key,(String)object);
        }
        else if(type.equals("Integer")){
            editor.putInt(key,(Integer) object);
        }
        else if(type.equals("Boolean")){
            editor.putBoolean(key,(Boolean) object);
        }else if(type.equals("Long")){
            editor.putLong(key,(Long)object);
        }
        editor.commit();

    }
    public  static  Object getParam(Context context,String key,Object object){

        SharedPreferences p=context.getSharedPreferences(NAME,Context.MODE_APPEND);
        String type=object.getClass().getSimpleName();
        if(type.equals("String")){
            return p.getString(key,(String)object);
        }
        else if(type.equals("Integer")){
            return p.getInt(key,(Integer)object);

        } else if (type.equals("Boolean")) {
            return p.getBoolean(key, (Boolean) object);

        } else if (type.equals("Long")) {
            return p.getLong(key, (Long) object);

        }
        return null;
    }
    //  SharePreferenceUtils.setParam(getApplicationContext(), "is_first", true);//
//      boolean is_first= (boolean) SharePreferenceUtils.getParam(getApplicationContext(),"is_first",false);
}

2. SDcardHelper

package myapplication.com.myapp.Utils;

import android.os.Environment;
import android.os.StatFs;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class SDcardHelper {

    /**
    *
    *
    * 判断sdcard是否挂载，可用
    * */
    public static boolean isSDcardMounted() {
        boolean state = Environment.getExternalStorageState().
                equals(Environment.MEDIA_MOUNTED);        
        return state;
    }
    
    /**
     * 获取sdcard的路径
     *
     */
    public static String getSDCardPath() {
        String path = Environment.getExternalStorageDirectory().getAbsolutePath();
        return path;
    }
    
    /**
     * 获取sdcard的大小
     *
     */
    public static long getSDCardSize() {
        if (isSDcardMounted()) {
            //
            StatFs sf = new StatFs(getSDCardPath());
            long count = sf.getBlockCount();
            long size = sf.getBlockSize();
            return count * size;
        }
        return 0;
    }
    
    /**
     * 获取sdcard的空余空间大小
     */
    
    public static long getSDCardFreeSize() {
        if (isSDcardMounted()) {
            StatFs sFs = new StatFs(getSDCardPath());
            long count = sFs.getFreeBlocks();
            long size = sFs.getBlockSize();
            return count * size;
        }
        return 0;
    }
    
    /**
     * 获取sdcard的可利用空间大小
     */
    
    public static long getSDCardAvailableSize() {
        if (isSDcardMounted()) {
            StatFs sFs = new StatFs(getSDCardPath());
            long count = sFs.getAvailableBlocks();
            long size = sFs.getBlockSize();
            return count * size;
        }
        return 0;
    }
    
    /**
     * 保存文件到sdcard
     * @param data  保存目标数组
     * @param dir  保存路径
     * @param filename  文件名
     * @return
     */
    public static boolean saveFileToSDCard(byte[] data, String dir,String filename) {
        if (isSDcardMounted()) {
            File filedir = new File(getSDCardPath() + File.separator + dir);
            if (!filedir.exists()) {
                filedir.mkdirs();
            }
            
            if (getSDCardAvailableSize() >= data.length) {
                FileOutputStream fos = null;
                try {
                    fos = new FileOutputStream(new File(filedir+File.separator+filename));
                    fos.write(data);
                    fos.flush();
                    return true;
                } catch (FileNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                finally {
                    if (fos != null) {
                        try {
                            fos.close();
                        } catch (IOException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                }
            }
        }
    
        return false;
    }

    /**
     * 从sdcard路径读取文件 ，返回字符数组
     *
     */

    public static byte[] readFileFromSDCard(String filepath)    {
        if (isSDcardMounted()) {
            File file = new File(filepath);
            ByteArrayOutputStream  byteArrayOutputStream = null;
            if (file.exists()) {
                FileInputStream fileInputStream = null;
                try {
                    fileInputStream = new FileInputStream(file);
                    byteArrayOutputStream = new ByteArrayOutputStream();
                    byte[] buffer = new byte[1024];
                    int length = 0;
                    while ((length = fileInputStream.read(buffer)) != -1) {
                        byteArrayOutputStream.write(buffer, 0, length);
                    }
                    
                    return byteArrayOutputStream.toByteArray();
                } catch (FileNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } finally {
                    if (fileInputStream != null) {
                        try {
                            fileInputStream.close();
                        } catch (IOException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                }
                
                
            }
        }
        return null;
    }
}

3.SqliteDbhelper 配合bean文件，dao一直使用

package myapplication.com.myapp.Utils;

import android.database.sqlite.SQLiteDatabase;

import java.io.File;


public class SQLiteDBHelper {
    private static String DB_PATH = SDcardHelper.getSDCardPath();
    private static String DB_NAME = "student.db";  // 数据库名称
    
    static {
        SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(DB_PATH+File.separator+DB_NAME, null);
        db.execSQL("create table if not exists student(_id integer primary key autoincrement," +
                "name varchar(20)," +
                "sex varchar(4)," +
                "address varchar(100)," +
                "money integer)");
        db.close();
    }
    
    public static SQLiteDatabase getSqLiteDatabase() {
        return SQLiteDatabase.openOrCreateDatabase(DB_PATH+File.separator+DB_NAME, null);
    }
    
}

package myapplication.com.myapp.bean;

public class Student {
    
    int id;
    String name;
    String sex;
    String address;
    int money;
    
    //  new Student(2, time, msg, reserved, 300)
    //  time ,msg ,reserved
    
    public Student(int id, String name, String sex, String address, int money) {
        super();
        this.id = id;
        this.name = name;
        this.sex = sex;
        this.address = address;
        this.money = money;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public int getMoney() {
        return money;
    }
    public void setMoney(int money) {
        this.money = money;
    }
    @Override
    public String toString() {
        return "Student [id=" + id + ", name=" + name + ", sex=" + sex
                + ", address=" + address + ", money=" + money + "]";
    }
    
    
    
}

package myapplication.com.myapp.bean;

import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

import java.util.ArrayList;
import java.util.List;

import myapplication.com.myapp.Utils.SQLiteDBHelper;


public class StudentDao {
    

    
    public boolean insert(Student stu) {
        SQLiteDatabase db = SQLiteDBHelper.getSqLiteDatabase();
        try {
            db.execSQL("insert into student (name,sex,address,money) values(?,?,?,?)",
                    new Object[]{stu.getName(),stu.getSex(),stu.getAddress(),stu.getMoney()});
            db.close();
            return true;
        } catch (Exception e) {
            // TODO: handle exception
        }

        return false;
    }

    public void delete(int id) {
        SQLiteDatabase db = SQLiteDBHelper.getSqLiteDatabase();
        //db.execSQL("delete from student where _id = ?", new Object[]{student.getId()});
        db.execSQL("delete from student where _id = "+id);
        db.close();
    }


    public void update(Student stu) {
        SQLiteDatabase db = SQLiteDBHelper.getSqLiteDatabase();
        db.execSQL("update student set name = ?,sex=?,address=?,money=? where _id = ?",
                new Object[]{stu.getName(),stu.getSex(),stu.getAddress(),stu.getMoney(),stu.getId()});
        db.close();
    }


    public Student findById(int id) {
        SQLiteDatabase db = SQLiteDBHelper.getSqLiteDatabase();
        Cursor cursor = db.rawQuery("select * from student where _id = ?", new String[]{id+""});
        Student student = null;
        if (cursor.moveToNext()) {
            int _id = cursor.getInt(cursor.getColumnIndex("_id"));
            String name = cursor.getString(cursor.getColumnIndex("name"));
            String sex = cursor.getString(cursor.getColumnIndex("sex"));
            String address = cursor.getString(cursor.getColumnIndex("address"));
            int money = cursor.getInt(cursor.getColumnIndex("money"));
            student = new Student(_id, name, sex, address, money);
        }
        return student;
    }


    public List<Student> findAll() {
        List<Student> list = new ArrayList<Student>();
        SQLiteDatabase db = SQLiteDBHelper.getSqLiteDatabase();
        //  db.rawQuery("select * from 表名 orderby KEY_ENDTIME"，null);
        //
        //　KEY_ENDTIME ASC 升序
        //　KEY_ENDTIME DESC 降序
        //Cursor cursor = db.rawQuery("select * from student", null);
        Cursor cursor = db.rawQuery("select * from student  order by money ASC",null);
        Student student = null;
        while (cursor.moveToNext()) {
            int _id = cursor.getInt(cursor.getColumnIndex("_id"));
            String name = cursor.getString(cursor.getColumnIndex("name"));
            String sex = cursor.getString(cursor.getColumnIndex("sex"));
            String address = cursor.getString(cursor.getColumnIndex("address"));
            int money = cursor.getInt(cursor.getColumnIndex("money"));
            student = new Student(_id, name, sex, address, money);
            list.add(student);
        }
        return list;
    }

}

 StudentDao studentDao = new StudentDao();
studentDao.insert(new Student(pci, cellname, lon, lat, pci));

   StudentDao studentDao=new StudentDao();
   List<Student> list=studentDao.findAll();