【达内课程】异常处理工具类、Log打印工具类、网络变化工具类

ExceptionUtil

public class ExceptionUtil {
    public static void handleException(Throwable throwable){

        if(MyApplication.isRelease){
            //把异常信息转成字符串
            StringWriter stringWriter = new StringWriter();
            PrintWriter printWriter = new PrintWriter(stringWriter);
            throwable.printStackTrace(printWriter);
            String str = stringWriter.toString();
            //联网发送

        }else {
            //开发阶段
            ExceptionUtil.handleException(throwable);
        }
    }
}

其中MyApplication.isRelease是定义在MyApplication中的变量，用来表示是否是发布版本，在真正发布时，置为true

    //release:发布版本
    public static boolean isRelease = false;

LogUtil

Log输出也不能随便用，耗时，可以通过两个栗子看一下

        long start = System.currentTimeMillis();
        int sum = 0;
        for(int i=0;i<10000;i++){
            sum++;
        }
        long end = System.currentTimeMillis() - start;
        Log.i("TIME",sum+" 用时："+end);

I/TIME: 10000 用时：1

        long start = System.currentTimeMillis();
        int sum = 0;
        for(int i=0;i<10000;i++){
            sum++;
            Log.i("TIME",sum+" 用时："+ (System.currentTimeMillis() - start));
        }

I/TIME: 9998 用时：201
I/TIME: 9999 用时：201
I/TIME: 10000 用时：201

因此我们写一个LogUtil

public class LogUtil {
    public static void i(String tag,Object msg){
        if(MyApplication.isRelease){
            //真机上不打印日志
            return;
        }else {
            Log.d(tag,String.valueOf(msg));
        }
    }
}

Toast

在工作中应该新建一个toast方法，以便统一修改toast样式

public static void showInfo(Context context, String msg){
	.....
}

其他toast教程：Android自定义Toast的时长、位置、及显示的View

NetworkUtil

添加权限

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

NetworkUtil

public class NetworkUtil {
    public static void checkNetworkState(final Activity activity){
        //判断有没有网
        ConnectivityManager manager = (ConnectivityManager)activity.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        //没有活动网络
        if(networkInfo == null){
            final AlertDialog.Builder builder = new AlertDialog.Builder(activity);
            builder.setMessage("没网");
            builder.setPositiveButton("打开网络", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    Intent intent = new Intent(Settings.ACTION_WIRELESS_SETTINGS);
                    activity.startActivity(intent);
                }
            });

            builder.setNegativeButton("取消", null);
            builder.show();
        }
    }
}

使用时在onCreate()中

   NetworkUtil.checkNetworkState(this);

NetworkStateChangeReceiver

NetworkStateChangeReceiver

public class NetworkStateChangeReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        NetworkUtil.checkNetworkType(context);
    }
}

AndroidManifest中注册

        <receiver android:name=".util.NetworkStateChangeReceiver">
            <intent-filter>
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
            </intent-filter>
        </receiver>

MyApplication

public class MyApplication extends Application {
    public static boolean networkIsClose = false;
    public static boolean networkIsMobile = false;
    public static boolean networkIsWifi = false;
    ......
    @Override
    public void onCreate() {
        super.onCreate();
        //得网络状态
		NetworkUtil.checkNetworkType(this);

        ......
    }
}

NetworkUtil中增加方法

 public static void checkNetworkType(Context context) {
        //判断用户是开网还是关网
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo info = manager.getActiveNetworkInfo();
        if (info == null) {
            //关网
            MyApplication.networkIsClose = true;
            MyApplication.networkIsWifi = false;
            MyApplication.networkIsMobile = false;
            LogUtil.i("网络", "用户关闭了网络");
        } else {
            //用户开网
            MyApplication.networkIsClose = false;
            //判断网络类型
            //移动网
            NetworkInfo networkMobile = manager.getNetworkInfo(manager.TYPE_MOBILE);
            if (networkMobile != null && networkMobile.isConnectedOrConnecting()) {
                MyApplication.networkIsMobile = true;
                LogUtil.i("网络", "用户打开了网络，网络类型是移动网");
            }
            //wifi
            NetworkInfo networkWifi = manager.getNetworkInfo(manager.TYPE_WIFI);
            if (networkWifi != null && networkWifi.isConnectedOrConnecting()) {
                MyApplication.networkIsWifi = true;
                LogUtil.i("网络", "用户打开了网络，网络类型是wifi");
            }
        }
    }

android.net.conn.CONNECTIVITY_CHANGE广播无法接收的问题