SDCARD文件工具類、聯網工具類、數據庫操做工具類

//操做SDCARD的文件工具類

public class FileUtil {
//存放圖片的路徑
 private static final String CACHE_DIR = Environment.getExternalStorageDirectory() + "/my_caches/images";

 private static int COMP_JPG = 0;
 private static int COMP_PNG = 1;
//判斷sdcard 是否掛載(是否有sdcard)
 public static boolean isMounted(){
  //獲取手機設備的sdcard狀態
  String state = Environment.getExternalStorageState();
  //MOUNTED -- 安裝
  return state.equals(Environment.MEDIA_MOUNTED);
 }

 //獲取sdcard文件 根路徑的絕對路徑
 public static String getSDCARD(){
  return Environment.getExternalStorageDirectory().getAbsolutePath();
 }

 //獲取文件名 
 public static String getFilename(String url){
  return url.substring(url.lastIndexOf('/') + 1);
 }

 //保存文件 方法1
 public static void sava1(String url,byte[] data){
  //判斷是否有sdcard
  if(!isMounted()){
  return ; 
  }
  //有sdcard
  //判斷是否有緩存文件夾
  File dir = new File(CACHE_DIR);
  if(!dir.exists()){
   //不存在緩存文件夾 建立文件夾用來保存文件
   dir.mkdirs();
  }
  //把文件 數據存到sdcard
  File file = new File(dir,getFilename(url));
  try {
   FileOutputStream fos = new FileOutputStream(file);
   fos.write(data);
   
   fos.close();
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
 
 //保存文件 方法2
 public static void sava2(String url,Bitmap bitmap,int format){
  //判斷 是否有sdcard
  if(!isMounted()){
   return ;
  }
  File dir = new File(CACHE_DIR);
  if(!dir.exists()){
   dir.mkdirs();
  }
  //把 文件數據 寫到 sdcard
  File file = new File(dir,getFilename(url));
  try {
   FileOutputStream fos = new FileOutputStream(file);
   //把圖片文件寫入緩存
   bitmap.compress((format == COMP_JPG?CompressFormat.JPEG:CompressFormat.PNG), 100, fos);
  
   fos.close();
  } catch (Exception e) {
   e.printStackTrace();
  }
  
 }
 //讀取圖片
 public static Bitmap readImage(String url){
  if(!isMounted()){
   return null;
  }
  File file = new File(CACHE_DIR,getFilename(url));
  if(file.exists()){
   return BitmapFactory.decodeFile(file.getAbsolutePath());
  }
  return null;
 }
 
 //清空 緩存目錄
 public void clearCaches(){
  File dir = new File(CACHE_DIR);
  File[] file_datas = dir.listFiles();
  for(File file : file_datas){
   file.delete();
  }
 }
 
 //生成略縮圖
 public static Bitmap creatThumbnail(String filepath,int newWidth,int newHeight){
  BitmapFactory.Options options = new BitmapFactory.Options();
  //
  options.inJustDecodeBounds = true;
  //目的：不生成bitmap數據，可是要獲取原圖的參數值
  BitmapFactory.decodeFile(filepath, options);
  //原有寬高
  int originalWidth = options.outWidth;
  int originalHeight = options.outHeight;
  //按比例縮小的寬高
  int width = originalWidth/newWidth;
  int height = originalHeight/newHeight;
  
  options.inSampleSize = height > width? height : width;
  
  options.inJustDecodeBounds = false;
  
  return BitmapFactory.decodeFile(filepath, options);
 }
 
}

===========================

//sql數據庫增刪改查工具類

public class Sqlite_operate_utils {

private static String DB_PATH = Environment.getExternalStorageDirectory() + File.separator + "studentinfo2.db";

private SQLiteDatabase db;

//構造函數 new 該類的時候 就去找 須要找的 數據庫

public Sqlite_operate_utils() {

db = SQLiteDatabase.openDatabase(DB_PATH, null, SQLiteDatabase.OPEN_READWRITE);

}

//查詢 數據的 方法1

public Cursor sqlite_select(String content, String[] condition){

return db.rawQuery(content, condition);

}

//查詢 數據 的 方法2

public List<Map<String, String>> sqlite_selectlist(String content, String[] condition){

Cursor cursor = db.rawQuery(content, condition);

return cursorToList(cursor);

}

//返回List

public List<Map<String, String>> cursorToList(Cursor cursor) {

List<Map<String, String>> list = new ArrayList<Map<String,String>>();

while(cursor.moveToNext()){//數據庫表的 行

Map<String, String> map = new HashMap<String, String>();

for(int i = 0;i<cursor.getColumnCount();i++){//數據庫表的列

map.put(cursor.getColumnName(i), cursor.getString(i));

}

list.add(map);

}

cursor.close();

return list;

}

//增刪改 的方法

//返回布爾型 方便 查看 數據 操做 是否成功

public boolean executeData(String execute_content, Object[] bindArgs){

try {

if(bindArgs == null){//要綁定佔位符 的參數值

db.execSQL(execute_content);

return true;

}else{

db.execSQL(execute_content, bindArgs);

return true;

}

} catch (SQLException e) {

e.printStackTrace();

return false;

}

}

=================================

//聯網工具類

/**

 * 聯網工具類 -- 用來下載圖片和文字數據

 * 

 * @author Administrator

 * 

 */

public class AUtil {

public static final int TYPE_IMG = 1;

public static final int TYPE_TXT = 2;

public static Handler handler = new Handler(){};

// 線程池

public static ExecutorService executor = Executors.newFixedThreadPool(5);

// 接口

public interface Callback {

public void responseTxt(String txtData);// 對文字數據的處理

public void responseImg(String url, Bitmap bitmap);// 對圖片數據的處理

public boolean isStopImg(String url);//判斷下載圖片是否出現 須要中止

}

/**

* 

* @param type -- 下載數據的類型

* @param url -- 下載的地址

* @param callback -- 接口

*/

public static void getAsync(final int type, final String url, final Callback callback) {

executor.execute(new Runnable() {

@Override

public void run() {

try {

//聯網下載數據 根據url

HttpGet get = new HttpGet(url);

HttpClient client = new DefaultHttpClient();

HttpResponse response = client.execute(get);

Log.i("data","===");

if(response.getStatusLine().getStatusCode() == 200){

//把下載完的數據存到一個數組

final byte[] downData = EntityUtils.toByteArray(response.getEntity());

Log.i("data", "downData.size" + downData.length);

if(callback.isStopImg(url)){//若是圖片有重置狀況 就終止下載

Log.i("data", "AUtil -- isStopImg");

return;

}

if(type == AUtil.TYPE_IMG){

//若是是圖片就把圖片保存到sdcard

ImageUtils.saveImg(url, downData);

}

//主線程 接口回調

handler.post(new Runnable() {

@Override

public void run() {

try {

if(type == AUtil.TYPE_IMG){//圖片更新

//使用接口

callback.responseImg(url, 

BitmapFactory.decodeByteArray(downData, 

0, downData.length));

}else if(type == AUtil.TYPE_TXT){//文字更新

callback.responseTxt(new String(downData,"utf-8"));

}

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

});

}

} catch (Exception e) {

e.printStackTrace();

}

}

});

}

}