清除緩存，數據庫，sharedPreference和files

<pre name="code" class="java">package com.sfdj.salebaby.util;

/*  * 文 件 名:  DataCleanManager.java  * 描    述:  主要功能有清除內/外緩存，清除數據庫，清除sharedPreference，清除files和清除自定義目錄  */

import java.io.File;
import java.math.BigDecimal;

import android.content.Context;
import android.os.Environment;

/** * 本應用數據清除管理器 */
public class DataCleanManager {
	
	public static String getTotalCacheSize(Context context) throws Exception {
        long cacheSize = getFolderSize(context.getCacheDir());
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {  
            cacheSize += getFolderSize(context.getExternalCacheDir());
        }  
        return getFormatSize(cacheSize);
    }
	
	// 獲取文件  
    //Context.getExternalFilesDir() --> SDCard/Android/data/你的應用的包名/files/ 目錄，一般放一些長時間保存的數據  
    //Context.getExternalCacheDir() --> SDCard/Android/data/你的應用包名/cache/目錄，一般存放臨時緩存數據  
    public static long getFolderSize(File file) throws Exception {  
        long size = 0;  
        try {  
            File[] fileList = file.listFiles();  
            for (int i = 0; i < fileList.length; i++) {  
                // 如果下面還有文件  
                if (fileList[i].isDirectory()) {  
                    size = size + getFolderSize(fileList[i]);  
                } else {  
                    size = size + fileList[i].length();  
                }  
            }  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
        return size;  
    }  
    
    public static void clearAllCache(Context context) {
        deleteDir(context.getCacheDir());
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {  
            deleteDir(context.getExternalCacheDir());
        }  
    }
   
    private static boolean deleteDir(File dir) {
    	if(dir == null){
    		return false;
    	}
        if (dir != null && dir.isDirectory()) {
            String[] children = dir.list();
            for (int i = 0; i < children.length; i++) {
                boolean success = deleteDir(new File(dir, children[i]));
                if (!success) {
                    return false;
                }
            }
        }
        return dir.delete();
    }
       
    /** 
     * 格式化單位 
     *  
     * @param size 
     * @return 
     */ 
    public static String getFormatSize(double size) {  
        double kiloByte = size / 1024;  
        if (kiloByte < 1) {  
//            return size + "Byte";  
            return "0K";
        }  
   
        double megaByte = kiloByte / 1024;  
        if (megaByte < 1) {  
            BigDecimal result1 = new BigDecimal(Double.toString(kiloByte));  
            return result1.setScale(2, BigDecimal.ROUND_HALF_UP)  
                    .toPlainString() + "KB";  
        }  
   
        double gigaByte = megaByte / 1024;  
        if (gigaByte < 1) {  
            BigDecimal result2 = new BigDecimal(Double.toString(megaByte));  
            return result2.setScale(2, BigDecimal.ROUND_HALF_UP)  
                    .toPlainString() + "MB";  
        }  
   
        double teraBytes = gigaByte / 1024;  
        if (teraBytes < 1) {  
            BigDecimal result3 = new BigDecimal(Double.toString(gigaByte));  
            return result3.setScale(2, BigDecimal.ROUND_HALF_UP)  
                    .toPlainString() + "GB";  
        }  
        BigDecimal result4 = new BigDecimal(teraBytes);  
        return result4.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString()  
                + "TB";  
    } 
	
	/** * 清除本應用內部緩存(/data/data/com.xxx.xxx/cache) * * @param context */
	public static void cleanInternalCache(Context context) {
		deleteFilesByDirectory(context.getCacheDir());
	}

	/** * 清除本應用所有數據庫(/data/data/com.xxx.xxx/databases) * * @param context */
	public static void cleanDatabases(Context context) {
		deleteFilesByDirectory(new File("/data/data/"
				+ context.getPackageName() + "/databases"));
	}

	/**
	 * * 清除本應用SharedPreference(/data/data/com.xxx.xxx/shared_prefs) * * @param
	 * context
	 */
	public static void cleanSharedPreference(Context context) {
		deleteFilesByDirectory(new File("/data/data/"
				+ context.getPackageName() + "/shared_prefs"));
	}

	/** * 按名字清除本應用數據庫 * * @param context * @param dbName */
	public static void cleanDatabaseByName(Context context, String dbName) {
		context.deleteDatabase(dbName);
	}

	/** * 清除/data/data/com.xxx.xxx/files下的內容 * * @param context */
	public static void cleanFiles(Context context) {
		deleteFilesByDirectory(context.getFilesDir());
	}

	/**
	 * * 清除外部cache下的內容(/mnt/sdcard/android/data/com.xxx.xxx/cache) * * @param
	 * context
	 */
	public static void cleanExternalCache(Context context) {
		if (Environment.getExternalStorageState().equals(
				Environment.MEDIA_MOUNTED)) {
			deleteFilesByDirectory(context.getExternalCacheDir());
		}
	}

	/** * 清除自定義路徑下的文件，使用需小心，請不要誤刪。而且只支持目錄下的文件刪除 * * @param filePath */
	public static void cleanCustomCache(String filePath) {
		deleteFilesByDirectory(new File(filePath));
	}

	/** * 清除本應用所有的數據 * * @param context * @param filepath */
	public static void cleanApplicationData(Context context, String... filepath) {
		cleanInternalCache(context);
		cleanExternalCache(context);
		cleanDatabases(context);
		cleanSharedPreference(context);
		cleanFiles(context);
		for (String filePath : filepath) {
			cleanCustomCache(filePath);
		}
	}

	/** * 刪除方法 這裏只會刪除某個文件夾下的文件，如果傳入的directory是個文件，將不做處理 * * @param directory */
	private static void deleteFilesByDirectory(File directory) {
		if (directory != null && directory.exists() && directory.isDirectory()) {
			for (File item : directory.listFiles()) {
				item.delete();
			}
		}
	}
}