【手机安全卫士02】连接服务器获取更新信息

在上一篇文章中我们已经开发好了对应的启动页面，今天我们将继续开发进去启动页面时自动的连接服务器，获取服务器上的最新信息，如果服务器上的版本大于当前版本的话，则弹出对话框提示下载更新，否则直接进入主界面！下面是效果图：

 下面是SplashActivity的全部代码：

package lq.wangzhen.mobilesafe;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import lq.wangzhen.mobilesafe.domain.UpdateInfo;
import lq.wangzhen.mobilesafe.engine.UpdateInfoParser;

import org.xmlpull.v1.XmlPullParserException;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.widget.TextView;
import android.widget.Toast;

public class SplashActivity extends Activity {
    private TextView tv_splash_version;
    private UpdateInfo info;
    
    private static final int GET_INFO_SUCCESS = 10;
    private static final int SERVER_ERROR = 11;
    private static final int SERVER_URL_ERROR = 12;
    private static final int IO_ERROR = 13;
    private static final int XML_PARSER_ERROR = 14;
    protected static final String TAG = "SplashActivity";
    
    private Handler handler = new Handler(){

        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case XML_PARSER_ERROR:
                Toast.makeText(getApplicationContext(), "XML解析异常", Toast.LENGTH_LONG).show();
                loadMainUI();   //加载主界面
                break;
            case IO_ERROR:
                Toast.makeText(getApplicationContext(), "IO异常", Toast.LENGTH_LONG).show();
                loadMainUI(); //加载主界面
                break;
            case SERVER_URL_ERROR:
                Toast.makeText(getApplicationContext(), "服务器URL出错", Toast.LENGTH_LONG).show();
                loadMainUI(); //加载主界面
                break;
            case SERVER_ERROR:
                Toast.makeText(getApplicationContext(), "服务器异常", Toast.LENGTH_LONG).show();
                loadMainUI();//加载主界面
                break;
            case GET_INFO_SUCCESS:
                String serverVersion = info.getVersion();   //取得服务器上的版本号
                String currentVersion = getVersion();       //取得当前应用的版本号
                if(currentVersion.equals(serverVersion)){   //判断两个版本号是否相同
                    Log.i(TAG, "版本号相同，进入主界面！");
                    loadMainUI();                //如果版本号相同，则进入主界面
                }else{
                    Log.i(TAG, "版本号不相同，对话框！");
                    showUpdateDialog();                     //如果版本号不相同，则加载更新对话框
                }
                break;

            default:
                break;
            }
        }
        
    };
    //加载主界面
    public void loadMainUI(){   
        Intent intent = new Intent(this,MainActivity.class);
        startActivity(intent);
        finish();   //结束当前的Activity
    }
    //显示升级对话框
    protected void showUpdateDialog() {
        AlertDialog.Builder builder = new Builder(this);    //实例化对话框
        builder.setIcon(getResources().getDrawable(R.drawable.notification));   //添加图标
        builder.setTitle("升级提示");   //添加标题
        builder.setMessage(info.getDescription());   //添加内容
        builder.setPositiveButton("升级", new OnClickListener() {    //点击升级时的操作方法
            @Override
            public void onClick(DialogInterface dialog, int which) {
                Log.i(TAG, "升级，地址："+info.getApkurl());
            }
        });
        builder.setNegativeButton("取消", new OnClickListener() {    //点击取消时的操作方法
            @Override
            public void onClick(DialogInterface dialog, int which) {
                loadMainUI();
            }
        });
        builder.create().show();   //显示对话框
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash);
        this.tv_splash_version = (TextView) this.findViewById(R.id.tv_splash_version);
        this.tv_splash_version.setText("版本号："+getVersion());   //设置应用程序的版本号
        new Thread(new CheckVersionTask()){}.start();    //启动一个线程进行服务器连接判断版本号是否相同
    }
    
    private class CheckVersionTask implements Runnable{
        @Override
        public void run() {
            Message msg = Message.obtain();
            //1、取得服务器地址
            String serverUrl = getResources().getString(R.string.serverurl);   //取得服务器地址
            //2、连接服务器
            try {
                URL url = new URL(serverUrl);   
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setConnectTimeout(5000);
                conn.setRequestMethod("GET");
                int code = conn.getResponseCode();
                if(code == 200){
                    InputStream is = conn.getInputStream();    //取得服务器返回的内容
                    info = UpdateInfoParser.getUpdateInfo(is);   //调用自己编写的方法，将输入流转换为UpdateInfo对象
                    msg.what = GET_INFO_SUCCESS;
                    handler.sendMessage(msg);
                }else{
                    msg.what = SERVER_ERROR;
                    handler.sendMessage(msg);
                }
            } catch (MalformedURLException e) {
                msg.what = SERVER_URL_ERROR;
                handler.sendMessage(msg);
                handler.sendMessage(msg);
            } catch (IOException e) {
                msg.what = IO_ERROR;
                handler.sendMessage(msg);
                e.printStackTrace();
            } catch (XmlPullParserException e) {
                msg.what = XML_PARSER_ERROR;
                handler.sendMessage(msg);
                e.printStackTrace();
            }
        }
    }
    /**
     * 取得应用的版本号
     * @return
     */
    public String getVersion(){
        PackageManager pm = getPackageManager();   //取得包管理器的对象，这样就可以拿到应用程序的管理对象
        try {
            PackageInfo info = pm.getPackageInfo(getPackageName(), 0);   //得到应用程序的包信息对象
            return info.versionName;   //取得应用程序的版本号
        } catch (NameNotFoundException e) {
            e.printStackTrace();
            //此异常不会发生
            return "";
        }
    }
}

以上代码中用到的UpdateInfoParser.getUpdateInfo()方法，如下：

package lq.wangzhen.mobilesafe.engine;

import java.io.IOException;
import java.io.InputStream;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import android.util.Xml;

import lq.wangzhen.mobilesafe.domain.UpdateInfo;

public class UpdateInfoParser {

    public static UpdateInfo getUpdateInfo(InputStream is) throws XmlPullParserException, IOException{
        XmlPullParser parser = Xml.newPullParser();   //取得XmlPullParser解析器，准备对XML进行解析
        parser.setInput(is, "UTF-8");
        UpdateInfo info = new UpdateInfo();    //实例化UpdateInfo对象
        int type = parser.getEventType();
        while(type != XmlPullParser.END_DOCUMENT){
            if(type==XmlPullParser.START_TAG){
                if("version".equals(parser.getName())){
                    String version = parser.nextText();
                    info.setVersion(version);
                }else if("description".equals(parser.getName())){
                    String description = parser.nextText();
                    info.setDescription(description);
                }else if("apkurl".equals(parser.getName())){
                    String apkurl = parser.nextText();
                    info.setApkurl(apkurl);
                }
            }
            type = parser.next();
        }
        return info;
    }
}

以上代码中用到的UpdateInfo类，此类是根据服务器中提供的info.xml对象编写的：

package lq.wangzhen.mobilesafe.domain;

public class UpdateInfo {

    private String version;   //服务器上的版本号
    private String description;  //升级信息
    private String apkurl;    //apk下载地址
    public String getVersion() {
        return version;
    }
    public void setVersion(String version) {
        this.version = version;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public String getApkurl() {
        return apkurl;
    }
    public void setApkurl(String apkurl) {
        this.apkurl = apkurl;
    }
    
    
}

在layout文件夹中新建立main.xml布局文件，作为应用程序的主界面，如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    
    <TextView 
        android:id="@+id/test"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="mainUI"/>

</LinearLayout>

建立对应的MainActivity.java，加载main.xml：

package lq.wangzhen.mobilesafe;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

}

在mainfest.xml文件中配置MainActivity:

<activity android:name="lq.wangzhen.mobilesafe.MainActivity"></activity> 

因为要访问网络，别忘了加入访问网络的权限哦：

<uses-permission android:name="android.permission.INTERNET"/>

 对应的源码下载地址：http://pan.baidu.com/share/link?shareid=1241370091&uk=1646729842