Androidラーニングシリーズ--Appキャッシュ管理

import java.io.File; 
import java.io.IOException; 
  
import android.util.Log; 
  
import com.tianxia.app.floworld.AppApplication; 
import com.tianxia.app.floworld.utils.FileUtils; 
import com.tianxia.app.floworld.utils.NetworkUtils; 
  
public class ConfigCache { 
    private static final String TAG = ConfigCache.class.getName(); 
  
    public static final int CONFIG_CACHE_MOBILE_TIMEOUT  = 3600000;  //1 hour 
    public static final int CONFIG_CACHE_WIFI_TIMEOUT    = 300000;   //5 minute 
  
    public static String getUrlCache(String url) { 
        if (url == null) { 
            return null; 
        } 
  
        String result = null; 
        File file = new File(AppApplication.mSdcardDataDir + "/" + getCacheDecodeString(url)); 
        if (file.exists() && file.isFile()) { 
            long expiredTime = System.currentTimeMillis() - file.lastModified(); 
            Log.d(TAG, file.getAbsolutePath() + " expiredTime:" + expiredTime/60000 + "min"); 
            //1. in case the system time is incorrect (the time is turn back long ago) 
            //2. when the network is invalid, you can only read the cache 
            if (AppApplication.mNetWorkState != NetworkUtils.NETWORN_NONE && expiredTime < 0) { 
                return null; 
            } 
            if(AppApplication.mNetWorkState == NetworkUtils.NETWORN_WIFI 
                   && expiredTime > CONFIG_CACHE_WIFI_TIMEOUT) { 
                return null; 
            } else if (AppApplication.mNetWorkState == NetworkUtils.NETWORN_MOBILE 
                   && expiredTime > CONFIG_CACHE_MOBILE_TIMEOUT) { 
                return null; 
            } 
            try { 
                result = FileUtils.readTextFile(file); 
            } catch (IOException e) { 
                e.printStackTrace(); 
            } 
        } 
        return result; 
    } 
  
    public static void setUrlCache(String data, String url) { 
        File file = new File(AppApplication.mSdcardDataDir + "/" + getCacheDecodeString(url)); 
        try { 
            //         ，       
            FileUtils.writeTextFile(file, data); 
        } catch (IOException e) { 
            Log.d(TAG, "write " + file.getAbsolutePath() + " data failed!"); 
            e.printStackTrace(); 
        } 
    } 
  
    public static String getCacheDecodeString(String url) { 
        //1.        
        //2.                   (              ，          ，         ) 
        if (url != null) { 
            return url.replaceAll("[.:/,%?&=]", "+").replaceAll("[+]+", "+"); 
        } 
        return null; 
    } 
}

void getConfig(){ 
        //         
        String cacheConfigString = ConfigCache.getUrlCache(CONFIG_URL); 
        //           ，       
        if (cacheConfigString != null) { 
            showConfig(cacheConfigString); 
        } else { 
            //        ，         
            //          1.   ;2.     ;3.       
            AsyncHttpClient client = new AsyncHttpClient(); 
            client.get(CONFIG_URL, new AsyncHttpResponseHandler(){ 
  
                @Override
                public void onSuccess(String result){ 
                    //    ，               
                    ConfigCache.setUrlCache(result,  CONFIG_URL); 
                    //     UI  ，     
                    showConfig(result); 
                } 
  
                @Override
                public void onFailure(Throwable arg0) { 
                    //      ，         ，        
                } 
  
            }); 
        } 
    }