Android開發：計算快取大小並且清空快取

TTMMJJ99發表於2017-12-11
Android快取

專案中碰到了計算快取大小和清空快取的功能，這個很常見的功能，幾乎每個APP都有，以為實現很簡單，網上搜了一大堆，發現都不是符合我需要的，而且經常刪除的沒有效果，於是又另外找了一些資料，折騰了蠻久，終於完成了

以下的這個類的功能很簡單，計算你的快取總大小，不管內部快取還是外部快取，和清空快取，包括內部和外部的快取一起清空，請本人親測，效果槓槓的。

 

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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();
    }
       
    // 獲取檔案 
    //Context.getExternalFilesDir() --> SDCard/Android/data/你的應用的包名/files/ 目錄，一般放一些長時間儲存的資料 
    //Context.getExternalCacheDir() --> SDCard/Android/data/你的應用包名/cache/目錄，一般存放臨時快取資料 
    public static long getFolderSize(File file) throws Exception { 
        long size = 0; 
        try { 
            File[] fileList = file.listFiles(); 
            for (int i = 0; i < fileList.length; i++) { 
                // 如果下面還有檔案 
                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"; 
    } 
       
       
    
}

 

 

當你在專案中需要查下快取大小，就使用getTotalCacheSize(Context)方法，清空快取，就使用clearAllCache(Context)方法

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