Android 缓存工具类

介绍

今天用到了缓存，需要清除缓存，所以就封装了一个缓存工具类，便于日后使用

功能

主要功能包括：获取缓存大小以及清除缓存
代码如下：

package com.wzl.reversalchallenge.utils

import android.content.Context
import android.os.Environment
import java.io.File

public class CacheUtil {

    companion object {

        // 获取外部缓存大小
        public fun getExternalCacheSize(context: Context?): String {

            return if (Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED) {
                formatSize(getFolderSize(context!!.externalCacheDir))
            } else {
                "0 B"
            }
        }

        // 获取全部缓存大小
        public fun getCacheSize(context: Context?): String {

            var totalSize: Long = getFolderSize(context!!.cacheDir)
            if (Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED) {
                totalSize += getFolderSize(context.externalCacheDir)
            }
            return formatSize(totalSize)
        }

        // 获取文件夹大小
        private fun getFolderSize(folder: File?): Long {

            var size: Long = 0
            val files: Array<File>? = folder!!.listFiles()
            for (file in files!!) {
                size += if (file.isDirectory) {
                    getFolderSize(file)
                } else {
                    file.length()
                }
            }
            return size
        }

        // 清除外部缓存
        public fun clearExternalCache(context: Context?) {
            if (Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED) {
                deleteFolder(context!!.externalCacheDir)
            }
        }

        // 清除全部缓存
        public fun clearAllCache(context: Context?) {
            deleteFolder(context!!.cacheDir)
            if (Environment.getExternalStorageState() == Environment.MEDIA_MOUNTED) {
                deleteFolder(context.externalCacheDir)
            }
        }

        // 删除文件夹
        private fun deleteFolder(folder: File?) : Boolean {

            if (folder != null && folder.isDirectory) {
                val files: Array<String>? = folder.list()
                for (file in files!!) {
                    if (!deleteFolder(File(folder, file))) {
                        return false
                    }
                }
                return folder.delete()
            }
            if (folder != null) {
                return folder.delete()
            } else {
                return false
            }
        }

        // 格式化缓存大小单位
        private fun formatSize(size: Long): String {

            val b = size
            val kb = b / 1024
            if (kb < 1) {
                return "$b B"
            }
            val mb = kb / 1024
            if (mb < 1) {
                return "$kb KB"
            }
            val gb = mb / 1024
            if (gb < 1) {
                return "$mb MB"
            }
            val tb = gb / 1024
            if (tb < 1) {
                return "$gb GB"
            } else {
                return "0"
            }
        }
    }
}

如有错误望指正