android 下载安装并打开apk

package com.orangewealth.orangeclient.manager;
import android.app.ProgressDialog;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.graphics.Paint;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.widget.Toast;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

/**
* Created by yangyang on 4/11/16.
*/
public class DownPackageManager {
private static final String TAG=DownPackageManager.class.getSimpleName();
private static DownPackageManager instance;

private DownPackageManager(){

}

private static DownPackageManager getInstance(){
if(instance==null){
instance=new DownPackageManager();
}
return instance;
}

//下载文件
public static File  getFileFromSercer(String path,ProgressDialog pd) throws Exception{
if(Environment.getExternalStorageState().equals((Environment.MEDIA_MOUNTED))){
String apkFile = Uri.parse(path).getLastPathSegment()+".apk";
URL url=new URL(path);
HttpURLConnection conn=(HttpURLConnection)url.openConnection();
conn.setConnectTimeout(5000);
pd.setMax(conn.getContentLength());
InputStream is=conn.getInputStream();
File file=new File(Environment.getExternalStorageDirectory(),apkFile);
FileOutputStream fos=new FileOutputStream(file);
BufferedInputStream bis=new BufferedInputStream(is);
byte[] buffer =new byte[1024];
int len;
int total=0;
while ((len=bis.read(buffer))!=-1){
fos.write(buffer,0,len);
total+=len;
//
pd.setProgress(total);
}
fos.close();
bis.close();
is.close();
return file;

}else {
return null;
}
}
//安装指定文件的包
public static void installApk(Context context, File file){
Intent intent=new Intent();

intent.setAction(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(file), "application/vnd.android.package-archive");
context.startActivity(intent);

}
//根据包名判断安装包是否安装
public  static boolean isAppInstalled(Context c,String packgename){
PackageInfo packageinfo;
try{
packageinfo=c.getPackageManager().getPackageInfo(packgename,0);
}catch (Exception e){
packageinfo=null;
e.getStackTrace();
}
if (packageinfo == null) {
//System.out.println("没有安装");
return false;
} else {
//System.out.println("已经安装");
return true;
}
}
//下载APK
public static void downLodeApk(final   Context context,final   String url){
final ProgressDialog pd;
pd=new ProgressDialog(context);
pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
pd.setMessage("正在下载应用");
pd.show();
pd.setCanceledOnTouchOutside(false);
// 因为新启的线程,所以要是final
new Thread(){
@Override
public void run(){
try{
File file=getFileFromSercer(url, pd);
installApk(context,file);
pd.dismiss();
}catch (Exception e){
Toast.makeText(context.getApplicationContext(), "下载新版本失败", Toast.LENGTH_SHORT).show();

}
}

}.start();

}
// 根据下载地址打开APK
public static void openApk( Context c,String packagenaem,Bundle bundle,String activity,String url){
if(isAppInstalled(c,packagenaem)){
Intent i=new Intent();
ComponentName cn=new ComponentName(packagenaem,activity);
i.setComponent(cn);
i.putExtras(bundle);
c.startActivity(i);
}else {//未安装
downLodeApk(c,url);
}
}

}