NetHelper.java

package cn.zadui.reader.helper;

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

import android.content.Context;
import android.content.pm.PackageManager.NameNotFoundException;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.util.Log;

public class NetHelper {

	public static final int CONNECT_TIMEOUT=20*1000;
	public static final int READ_TIMEOUT=20*1000;
//	public static final String HOST_NAME="172.29.0.72";
//	public static final String HOST_NAME="192.168.1.104";
	public static final String HOST_NAME="meili.51leiju.cn";
	public static final String PORT="80";
	
	public static String webPath(String protocol,String path){
		return protocol+"://"+HOST_NAME+":"+PORT+path;
	}
	
	/**
	 * Detects current network connection type
	 * @param ctx
	 * @return -1 means no network available.
	 */
	public static int currentNetwork(Context ctx){
		ConnectivityManager connectivityManager = (ConnectivityManager) ctx.getSystemService(Context.CONNECTIVITY_SERVICE);
		NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();	
		return activeNetworkInfo==null ? -1 : activeNetworkInfo.getType();
	}
	
	public static HttpURLConnection buildUrlConnection(String url) throws IOException{
		URL u=new URL(url);
		HttpURLConnection con=(HttpURLConnection)u.openConnection();
		con.setInstanceFollowRedirects(true);
		con.setConnectTimeout(NetHelper.CONNECT_TIMEOUT);
		con.setReadTimeout(NetHelper.READ_TIMEOUT);
		return con;
	}
	
	public static boolean needUpdate(Context ctx){
		try {
			int currentVersion=ctx.getPackageManager().getPackageInfo(ctx.getPackageName(), 0).versionCode;
			boolean hasNewVersion=Settings.getBooleanPreferenceValue(ctx, Settings.PRE_HAS_NEW_VERSION, false);
			if (currentVersion>=Settings.getLongPreferenceValue(ctx, Settings.PRE_LAST_BUILD, currentVersion)){
				if (hasNewVersion){
					Settings.updateBooleanPreferenceValue(ctx, Settings.PRE_HAS_NEW_VERSION, false);
					Settings.updateLongPreferenceValue(ctx, Settings.PRE_LAST_BUILD, currentVersion);	
				}
				return false;
			}else{
				return true;
			}
		} catch (NameNotFoundException e) {
			return false;
		}
	}
	
	/**
	 * Check new version only for third party market because Google Android Market provides update function. 
	 */
	public static void checkNewVersion(Context ctx){
		Log.d(TAG,"IN checkNewVersion method");
		if (Settings.installedFromGoogleMarket(ctx)) return;
		if (Settings.getBooleanPreferenceValue(ctx, Settings.PRE_HAS_NEW_VERSION, false)) return;
		String lastBuild=getStringFromNetIO(NetHelper.webPath("http", "/client/version"));
		Log.d(TAG,"Last version is => "+lastBuild);
		if (lastBuild==null) return;
		try {
			int currentVersion=ctx.getPackageManager().getPackageInfo(ctx.getPackageName(), 0).versionCode;
			Log.d(TAG,"installed version is => "+String.valueOf(currentVersion));
			if (Integer.parseInt(lastBuild)>currentVersion){
				Log.d(TAG,"Set new version available flag");
				Settings.updateBooleanPreferenceValue(ctx, Settings.PRE_HAS_NEW_VERSION, true);
				Settings.updateLongPreferenceValue(ctx, Settings.PRE_LAST_BUILD, Integer.parseInt(lastBuild));
			}
		} catch (NameNotFoundException e) {
			e.printStackTrace();
		} catch (Exception ce){
			ce.printStackTrace();
		}
	}
	
	
	public static String getStringFromNetIO(String url){
		HttpURLConnection con=null;
		try {
			con=buildUrlConnection(url);
			InputStream in=con.getInputStream();
			ByteArrayOutputStream out=new ByteArrayOutputStream();
			byte[] buf=new byte[1024*8];
			int readCount=0;
			while((readCount=in.read(buf))!=-1){
				out.write(buf, 0, readCount);
			}
			String result=out.toString("UTF-8");
			return result;
		} catch (IOException e) {
			e.printStackTrace();
			return null;
		} finally{
			con.disconnect();
		}
	}
	
	static final String TAG="NetHelper";
}