1.SharedPreferencesUtils? 引導(dǎo)頁一般用來保存打開記錄

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 {/***** 判斷sdcard是否掛載，可用* */public static boolean isSDcardMounted() {boolean state = Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED); return state;}/*** 獲取sdcard的路徑**/public static String getSDCardPath() {String path = Environment.getExternalStorageDirectory().getAbsolutePath();return path;}/*** 獲取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;}/*** 獲取sdcard的空余空間大小*/public static long getSDCardFreeSize() {if (isSDcardMounted()) {StatFs sFs = new StatFs(getSDCardPath());long count = sFs.getFreeBlocks();long size = sFs.getBlockSize();return count * size;}return 0;}/*** 獲取sdcard的可利用空間大小*/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 保存目標(biāo)數(shù)組* @param dir 保存路徑* @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;}/*** 從sdcard路徑讀取文件 ，返回字符數(shù)組**/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"; // 數(shù)據(jù)庫名稱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 ,reservedpublic 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;}@Overridepublic 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();

?

轉(zhuǎn)載于:https://www.cnblogs.com/galibujianbusana/p/6129400.html

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