计算缓存大小和清空缓存

项目中碰到了计算缓存大小和清空缓存的功能，这个很常见的功能，几乎每个APP都有，以为实现很简单，网上搜了一大堆，发现都不是符合我需要的，而且经常删除的没有效果，于是又另外找了一些资料，折腾了蛮久，终于完成了

以下的这个类的功能很简单，计算你的缓存总大小，不管内部缓存还是外部缓存，和清空缓存，包括内部和外部的缓存一起清空，请本人亲测，效果杠杠的。

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);
        }
   
   
    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 && 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();
    }
       
    // 获取文件  
    //Context.getExternalFilesDir() --> SDCard/Android/data/你的应用的包名/files/ 目录，一般放一些长时间保存的数据  
    //Context.getExternalCacheDir() --> SDCard/Android/data/你的应用包名/cache/目录，一般存放临时缓存数据  
    public static long getFolderSize(File file) throws Exception {  
        long size = 0;  
        try {  
            File[] fileList = file.listFiles();  
            for (int i = 0; i < fileList.length; i++) {  
                // 如果下面还有文件  
                if (fileList[i].isDirectory()) {  
                    size = size + getFolderSize(fileList[i]);  
                } else {  
                    size = size + fileList[i].length();  
                }  
            }  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
        return size;  
    }  
       
    /** 
     * 格式化单位 
     *  
     * @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";  
    }  
       
       
    
}

当你在项目中需要查下缓存大小，就使用getTotalCacheSize(Context)方法，清空缓存，就使用clearAllCache(Context)方法

之前在网上查了很多别人写的方法，查询可以用，当清空往往是无效的，这个无效的方法如下：

private static void deleteFilesByDirectory(File directory) {  
        if (directory != null && directory.exists() && directory.isDirectory()) {  
            for (File item : directory.listFiles()) {  
                item.delete();  
            }  
        }  
    }