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();
时间： 2024-08-22 11:13:44