android获取应用程序大小,缓存数据信息

package com.xj.appinfo.activity;

import java.lang.reflect.Method;

import android.app.Activity;
import android.content.pm.IPackageStatsObserver;
import android.content.pm.PackageManager;
import android.content.pm.PackageStats;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.TextView;

public class MainActivity extends Activity {
private TextView tv;
private static final String ATTR_PACKAGE_STATS="PackageStats";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
tv=new TextView(this);
setContentView(tv);
getpkginfo("com.xj.notebook");
}
private Handler mHandler = new Handler() {
public void handleMessage(Message msg) {
switch (msg.what) {
case 1:
String infoString="";
PackageStats newPs = msg.getData().getParcelable(ATTR_PACKAGE_STATS);
if (newPs!=null) {
infoString+="应用程序大小: "+formatFileSize(newPs.codeSize);
infoString+="\n数据大小: "+formatFileSize(newPs.dataSize);
infoString+="\n缓存大小: "+formatFileSize(newPs.cacheSize);
}
tv.setText(infoString);
break;
default:
break;
}
}
};
public void getpkginfo(String pkg){
PackageManager pm = getPackageManager();
try {
Method getPackageSizeInfo = pm.getClass().getMethod("getPackageSizeInfo", String.class,IPackageStatsObserver.class);
getPackageSizeInfo.invoke(pm, pkg,new PkgSizeObserver());
} catch (Exception e) {
}
}
class PkgSizeObserver extends IPackageStatsObserver.Stub {
public void onGetStatsCompleted(PackageStats pStats, boolean succeeded) {
Message msg = mHandler.obtainMessage(1);
Bundle data = new Bundle();
data.putParcelable(ATTR_PACKAGE_STATS, pStats);
msg.setData(data);
mHandler.sendMessage(msg);

}
}

/**
* 获取文件大小
*
* @param length
* @return
*/
public static String formatFileSize(long length) {
String result = null;
int sub_string = 0;
if (length >= 1073741824) {
sub_string = String.valueOf((float) length / 1073741824).indexOf(
".");
result = ((float) length / 1073741824 + "000").substring(0,
sub_string + 3)
+ "GB";
} else if (length >= 1048576) {
sub_string = String.valueOf((float) length / 1048576).indexOf(".");
result = ((float) length / 1048576 + "000").substring(0,
sub_string + 3)
+ "MB";
} else if (length >= 1024) {
sub_string = String.valueOf((float) length / 1024).indexOf(".");
result = ((float) length / 1024 + "000").substring(0,
sub_string + 3)
+ "KB";
} else if (length < 1024)
result = Long.toString(length) + "B";
return result;
}
}