Android Studio网络请求

XML一个按钮,用来吐司网络获取的json数据;
一个网络请求类,用来封装两个方法一个是判断网络,一个是请求的类型(GET));

public static boolean isNetWork(Context context) {
        if (context != null) {
        //获取管理器
            ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo info = connectivityManager.getActiveNetworkInfo();
            if (info != null) {
				//返回 网络可用
                return info.isAvailable();
            }

        }
        //网络不可用
        return false;
    }

上面是判断网络,返回网络的状态;
这个是请求的类型还有,一些设置 拼接字符串;

public static String HttpGet(String strUrl){
        try {
        	//调用方法时,输入的接口
            URL url = new URL(strUrl);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
           //设置为get请求
            connection.setRequestMethod("GET");
            //设置连接主机超时时间
            connection.setConnectTimeout(5000);
            //设置从主机读取数据超时
            connection.setReadTimeout(5000);

            int code = connection.getResponseCode();
			//获取请求码 200 300 400 404等 200是网络成功
            if (code == 200) {
            //字符串拼接 可以用其他方法
                InputStream inputStream = connection.getInputStream();
                BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "utf-8"));
                StringBuffer buffer = new StringBuffer();
                String str = "";
                while ((str = reader.readLine()) != null) {
                    buffer.append(str);
                }
                //返回拼接的字符串
                return buffer.toString();
            }
            //释放connection占用的内存
            connection.disconnect();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

这里如果没有权限会报错;

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

这个方法类,我们已经写好了,下面是按钮点击要开启一个线程

new Thread(){
                @Override
                public void run() {
                    super.run();
                    //在这里写耗时操作(请求网络数据)
                    boolean networkConnected = Http.isNetworkConnected(MainActivity.this);
                    //判断有没有网
                    if (networkConnected){
                        //有网就请求数据
                        // 双引号是接口的地址 写好Bean类
                        String get = Http.requestHttpGet("");
                        //Gson解析 记得导包
                        Gson gson=new Gson();
                        JsonBean bean = gson.fromJson(get, JsonBean.class);
                        //把数据传递给主线程
                        Message message=new Message();
                        message.what=0;
                        message.obj=bean;
                        handler.sendMessage(message);
                    }else{
                       handler.sendEmptyMessageDelayed(1,0);
                    }

                }
                //注意 线程启动
            }.start();

Handler

Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
        switch (msg.what){
            case 0:
                JsonBean bean= (JsonBean) msg.obj;
                Toast.makeText(MainActivity.this,""+bean.toString(),Toast.LENGTH_LONG).show();

                break;
            case 1:
                //没网就提示用户 没网
                Toast.makeText(MainActivity.this,"没网",Toast.LENGTH_LONG).show();
                break;
        }
        }
    };