android显示缓存大小和清除缓存功能

项目中经常需要一个功能，就是显示缓存的大小和点击清除缓存功能。下面来写怎么实现该功能

andorid 缓存的话，一般分
1.cache缓存，cache缓存又分为外部sd卡cache和内部sd卡cache。
内部sd卡cache路径在
data/data//cache 下的文件
外部sd卡cache路径在
SDCard/Android/data//cache下的文件
2.File存储
路径在内部sd卡中，
data/data//files下的内容
3.database存储
路径在内部sd卡中，
data/data//databases下的内容
4.sharedPrefence存储。
路径在内部sd卡中，
data/data//shared_prefs下的内容
而我们要将上面几个的内容全部计算出来，然后清除。

下面是清除缓存的工具类

public class DataCleanManager {    /**     * 总的缓存数大小     *     * @param context     * @return     */    public static String getTotalCacheSize(Context context) throws Exception {        long cacheSize = getFloderSize(context.getCacheDir());//获取data/data/cn.xxx.xxx（当前包）/cache 下的文件大小   内部sd卡cache文件大小        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))//是否有sd卡，如果有sd卡        {            cacheSize += getFloderSize(context.getExternalCacheDir());//获取SDCard/Android/data/你的应用包名/cache/目录 外部sd卡cache文件大小        }        cacheSize += getFloderSize(new File("/data/data/"                + context.getPackageName() + "/databases"));  // 本应用所有数据库文件大小 data/data/<package name>/databases        cacheSize += getFloderSize(new File("/data/data/"                + context.getPackageName() + "/shared_prefs"));//清除本应用SharedPreference(/data/data/<package name>/shared_prefs)        cacheSize += getFloderSize(context.getFilesDir());//清除/data/data/<package name>/files下的内容        return getformatSize(cacheSize);    }    /**     * 清除缓存     *     * @param dir     * @return     */    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();    }  /**     * 清除所有缓存     *     * @param dir     * @return     */    public static void clearAllCache(Context context) {        deleteDir(context.getCacheDir());        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {            deleteDir(context.getExternalCacheDir());        }        deleteDir(new File("/data/data/"                + context.getPackageName() + "/databases"));// 本应用所有数据库文件大小 data/data/<package name>/databases        deleteDir(new File("/data/data/"                + context.getPackageName() + "/shared_prefs"));//清除本应用SharedPreference(/data/data/<package name>/shared_prefs)        deleteDir(context.getFilesDir());//清除/data/data/<package name>/files下的内容    }    /**     * 获取文件的大小     *     * @param file     * @return     */    public static long getFloderSize(File file) throws Exception {        long size = 0;        try {            File[] flieList = file.listFiles();//获取该目录下所有file和目录            for (int i = 0; i < flieList.length; i++) {                //如果下面还有文件                if (flieList[i].isDirectory()) {                    size = size + getFloderSize(flieList[i]);                } else {                    size = size + flieList[i].length();//获取文件大小                }            }        } catch (Exception e) {            e.printStackTrace();        }        return size;    }    /**     * 格式化单位     *     * @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";    }}

然后我们写个测试

activity_show_acache_and_clear_achache.xml文件

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical">    <TextView        android:id="@+id/tv_save_size"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:padding="10dp"        android:text="" />    <TextView        android:id="@+id/tv_clear"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:padding="10dp"        android:text="清除缓存" /></LinearLayout>

activity文件

package test.my.com.hellochina.view;import android.app.Activity;import android.content.Context;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.View;import android.widget.TextView;import android.widget.Toast;import java.lang.ref.WeakReference;import butterknife.BindView;import butterknife.ButterKnife;import butterknife.OnClick;import test.my.com.hellochina.R;import test.my.com.hellochina.app.MyApplication;import test.my.com.hellochina.util.DataCleanManager;/** * 显示缓存和删除缓存 */public class ShowACacheAndClearAchacheActivity extends Activity {    @BindView(R.id.tv_save_size)    TextView tvSaveSize;    @BindView(R.id.tv_clear)    TextView tvClear;    MyHandler mHandler = new MyHandler(this);    private Thread mThread;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_show_acache_and_clear_achache);        ButterKnife.bind(this);        try {            tvSaveSize.setText(getString(R.string.cache_size,DataCleanManager.getTotalCacheSize(this)));        } catch (Exception e) {            e.printStackTrace();        }    }    @OnClick(R.id.tv_clear)    public void onViewClicked(View view) {        switch (view.getId()) {            case R.id.tv_clear://清除缓存                clearAllCache();                break;        }    }    public static class MyHandler extends Handler {        private WeakReference<Context> refrence;        @Override        public void handleMessage(Message msg) {            switch (msg.what) {                case 0:                    Toast.makeText(MyApplication.getContext(), "清理完成", Toast.LENGTH_SHORT).show();                    ShowACacheAndClearAchacheActivity showACacheAndClearAchacheActivity = (ShowACacheAndClearAchacheActivity) refrence.get();                    if (showACacheAndClearAchacheActivity != null) {                        try {                            showACacheAndClearAchacheActivity.tvSaveSize.setText(MyApplication.getContext().getString(R.string.cache_size,DataCleanManager.getTotalCacheSize(MyApplication.getContext())));                        } catch (Exception e) {                            e.printStackTrace();                        }                    }                    break;            }        }        public MyHandler(Context context) {            refrence = new WeakReference<>(context);        }    }    /**     * 清除缓存     */    private void clearAllCache() {        mThread = new Thread(new clearCache(this));//创建一个thread，用于清理内存，        mThread.start();    }    /**     * Runable 对象     */    private static class clearCache implements Runnable {        private WeakReference<Context> refrence;        public clearCache(Context context) {            refrence = new WeakReference<>(context);        }        @Override        public void run() {            clear();        }        private void clear() {            try {                DataCleanManager.clearAllCache(MyApplication.getContext());                Thread.sleep(3000);                if (DataCleanManager.getTotalCacheSize(MyApplication.getContext()).startsWith("0"))//如果完成                {                    ShowACacheAndClearAchacheActivity showACacheAndClearAchacheActivity = (ShowACacheAndClearAchacheActivity) refrence.get();                    if (showACacheAndClearAchacheActivity != null) {                        try {                            showACacheAndClearAchacheActivity.mHandler.sendEmptyMessage(0);                        } catch (Exception e) {                            e.printStackTrace();                        }                    }                }            } catch (InterruptedException e) {                e.printStackTrace();            } catch (Exception e) {                e.printStackTrace();            }        }    }    @Override    protected void onDestroy() {        super.onDestroy();        mHandler.removeCallbacksAndMessages(null);        mThread.stop();    }}

将获取context的方法放在application中，用来共用。先自定义一个application.

public class MyApplication extends Application {   private static Context context;  @Override    public void onCreate() {        super.onCreate();        context = getApplicationContext();    }  public static Context getContext() {        return context;    }}

AndroidManifest中定义<application        android:name=".app.MyApplication"        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme">  </application>

绑定控件用到了ButterKnife插件,具体使用可以看

ButterKnife插件

这样就能实现显示缓存大小和清除缓存功能。

参考资料：

Android 清除缓存详细实现（显示缓存大小）

Android开发：计算缓存大小并且清空缓存