Android实现清除应用缓存功能

import android.content.Context;
import android.os.Environment;
import java.io.File;
import java.math.BigDecimal;
 
/**
 * 获取缓存大小并清理缓存
 */
 
public class DataCleanManagerUtils {
 
 /**
  * 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
  */
 
 /**
  * 获取缓存值
  */
 public static String getTotalCacheSize(Context context) {
 
  long cacheSize = getFolderSize(context.getCacheDir());
  if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
   cacheSize += getFolderSize(context.getExternalCacheDir());
  }
  return getFormatSize(cacheSize);
 }
 
 /**
  * 清除所有缓存
  */
 public static void clearAllCache(Context context) {
  deleteDir(context.getCacheDir());
  if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
   deleteDir(context.getExternalCacheDir());
   //TODO 有网页清理时注意排错，是否存在/data/data/应用package目录下找不到database文件夹的问题
   context.deleteDatabase("webview.db");
   context.deleteDatabase("webviewCache.db");
  }
 }
 
 /**
  * 删除某个文件
  */
 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();
  }
  if (dir != null) {
   return dir.delete();
  } else {
   return false;
  }
 }
 
 /**
  * 获取文件
  */
 public static long getFolderSize(File file) {
  long size = 0;
  if (file != null) {
   File[] fileList = file.listFiles();
   if (fileList != null && fileList.length > 0) {
    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();
     }
    }
   }
  }
  return size;
 }
 
 /**
  * 格式化单位
  */
 public static String getFormatSize(double size) {
  double kiloByte = size / 1024;
  double megaByte = kiloByte / 1024;
  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 = BigDecimal.valueOf(teraBytes);
  return result4.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString()
   + "TB";
 }
}