清除缓存

[blackberry]代码库

//帮助类
public class DataClearManager {
    /**
     * * 清除本应用内部缓存(/data/data/com.xxx.xxx/cache) * *
     *
     * @param context
     */
    public static void cleanInternalCache(Context context) {
        deleteFilesByDirectory(context.getCacheDir());
    }

    /**
     * * 清除本应用所有数据库(/data/data/com.xxx.xxx/databases) * *
     *
     * @param context
     */
    public static void cleanDatabases(Context context) {
        deleteFilesByDirectory(new File("/data/data/"
                + context.getPackageName() + "/databases"));
    }

    /**
     * * 清除本应用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"));
    }

    /**
     * * 按名字清除本应用数据库 * *
     *
     * @param context
     * @param dbName
     */
    public static void cleanDatabaseByName(Context context, String dbName) {
        context.deleteDatabase(dbName);
    }

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

    /**
     * * 清除外部cache下的内容(/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());
        }
    }

    /**
     * * 清除自定义路径下的文件，使用需小心，请不要误删。而且只支持目录下的文件删除 * *
     *
     * @param filePath
     */
    public static void cleanCustomCache(String filePath) {
        deleteFilesByDirectory(new File(filePath));
    }

    /**
     * * 清除本应用所有的数据 * *
     *
     * @param context
     * @param filepath
     */
    public static void cleanApplicationData(Context context, String... filepath) {
        cleanInternalCache(context);
        cleanExternalCache(context);
        cleanDatabases(context);
        cleanSharedPreference(context);
        cleanFiles(context);
        if (filepath == null) {
            return;
        }
        for (String filePath : filepath) {
            cleanCustomCache(filePath);
        }
    }

    /**
     * * 删除方法 这里只会删除某个文件夹下的文件，如果传入的directory是个文件，将不做处理 * *
     *
     * @param directory
     */
    private static void deleteFilesByDirectory(File directory) {
        if (directory != null && directory.exists() && directory.isDirectory()) {
            for (File item : directory.listFiles()) {
                item.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;
    }

    /**
     * 删除指定目录下文件及目录
     *
     * @param deleteThisPath

     * @return
     */
    public static void deleteFolderFile(String filePath, boolean deleteThisPath) {
        if (!TextUtils.isEmpty(filePath)) {
            try {
                File file = new File(filePath);
                if (file.isDirectory()) {// 如果下面还有文件
                    File files[] = file.listFiles();
                    for (int i = 0; i < files.length; i++) {
                        deleteFolderFile(files[i].getAbsolutePath(), true);
                    }
                }
                if (deleteThisPath) {
                    if (!file.isDirectory()) {// 如果是文件，删除
                        file.delete();
                    } else {// 目录
                        if (file.listFiles().length == 0) {// 目录下没有文件或者目录，删除
                            file.delete();
                        }
                    }
                }
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    /**
     * 格式化单位
     *
     * @param size
     * @return
     */
    public static String getFormatSize(double size) {
        double kiloByte = size / 1024;
        if (kiloByte < 1) {
            return size + "Byte";
        }

        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";
    }

    	
    public static String getCacheSize(File file) throws Exception {
        return getFormatSize(getFolderSize(file));
    }

}


//main方法
private TextView tv_cache_size;
    private long totalSize;
    private File cacheDir;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv_cache_size = (TextView) findViewById(R.id.tv_cache_size);


        //人为的写入缓存信息
        cacheDir = getCacheDir();


        writeCache(cacheDir);
        //显示当前缓存的大小
        try {
            String size = DataClearManager.getCacheSize(cacheDir);
            tv_cache_size.setText(size);
        } catch (Exception e) {
            e.printStackTrace();
        }
//         String size=  getCacheSize(cacheDir);


        //缓存的大小-Cache Files
        //SD 当前放置缓存信息的目录
        //所有的 都删除
        //除了sharedPreference不删除

        //获取当前文件夹下边所有文件的总大小

    }

    /**
     * 获取缓存目录下的文件大小
     *
     * @param cacheDir
     * @return
     */
    private String getCacheSize(File cacheDir) {
        //先置位
        totalSize = 0;

        getCacheSizeMethod(cacheDir);
        //字节大小转成字符串  222222     12KB
        return formartSize(totalSize);
    }

    private String formartSize(long totalSize) {
        //小于1K
        if (totalSize < 1024) {
            return totalSize + "字节";
        } else {
            if ((totalSize / 1024) < 1024) {
                //kb范围以内
                return totalSize / 1024 + "kb";
            }
        }
        return null;
    }

    /**
     * 递归判断
     *
     * @param cacheDir
     */
    private void getCacheSizeMethod(File cacheDir) {
        //获取当前所有的大小
        File[] files = cacheDir.listFiles();
        if (files != null) {
            for (File file : files) {
                //是文件夹
                if (file.isDirectory()) {
                    //继续获取
                    getCacheSizeMethod(file);
                } else {
                    //是文件---获取当前文件的大小
                    long length = file.length();
                    totalSize = totalSize + length;
                }
            }

        }
    }

    /**
     * 模拟存储缓存内容
     *
     * @param cacheDir
     */
    private void writeCache(File cacheDir) {
        try {
            FileOutputStream fileOutputStream = new FileOutputStream(new File(cacheDir, "aaaa.txt"));
            fileOutputStream.write("dhoadhlfajdlsjddddddddddddddddddakfsavoannvkawodqqqqqfnawdnfawnvvnkanvaovnjaonvalvnakdjfnajdvjjdjjdjdjdjdjdjdjdjdjdjdjakdnfaeo;aeo".getBytes());
            fileOutputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

        File file = new File(cacheDir, "uuuu");
        if (!file.exists()) {
            file.mkdirs();
        }
        try {
            FileOutputStream fileOutputStream = new FileOutputStream(new File(file, "bbbb.txt"));
            fileOutputStream.write("dhoadhlfajdlsjddddddddddddddddddakfsavoannvkawodfnawdnfawnvvnkanvaovnjaonvalvnakdjfnajdvjjdjjdjdjdjdjdjdjdjdjdjdjakdnfaeo;aeo".getBytes());
            fileOutputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
    /**
     * 清除缓存
     * @param view
     */
    public void clearCache(View view) {
//        clearAllCache(cacheDir);
        //判断是否删光
//        String cacheSize = getCacheSize(cacheDir);
        //删除某个指定文件夹下的所有信息
        DataClearManager.deleteFolderFile(cacheDir.getAbsolutePath(), true);
        String size = null;
        try {
            size = DataClearManager.getCacheSize(cacheDir);
        } catch (Exception e) {
            e.printStackTrace();
        }
        tv_cache_size.setText(size);
    }
    private void clearAllCache(File cacheDir) {
        File[] files = cacheDir.listFiles();
        //uuuu列出所有  bbb.txt
        for (File file : files) {
            if (file.isDirectory()) {
                //如果是文件夹，还是得判断
                if (file.listFiles().length == 0) {
                    //空文件夹
                    file.delete();
                } else {
                    //继续递归删除文件
                    clearAllCache(file);
                }
            } else {
                file.delete();
            }
        }
        //删除uuu
        cacheDir.delete();
    }

//main布局
<TextView
        android:id="@+id/tv_cache_size"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="当前缓存大小是:" />

    <Button
        android:text="清除缓存"
        android:onClick="clearCache"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />