Handler子线程，Gson解析，get请求

    ## 代码要求和功能： Handler子线程，Gson解析，get请求。最终吐司。


 **1：首先创建Htttp包：**
public static boolean isNotABoolean(Context context) {

        //判断参数是否为空
        if (context != null) {

            //获取连接管理器
            ConnectivityManager systemService = (ConnectivityManager)
                    context.getSystemService(Context.CONNECTIVITY_SERVICE);

            //获取网络状态
            NetworkInfo info = systemService.getActiveNetworkInfo();

            if (info != null) {
                //判断网络是否可用
                return info.isAvailable();
            }
        }
        return false;
    }

   **:2：请求数据，get请求**
   
   public static String requesHttpGet(String s) {

        try {
            //设置url
            URL url = new URL(s);

            //打开链接
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();

            //设置get请求
            connection.setRequestMethod("GET");

            //设置链接主机时间
            connection.setConnectTimeout(5000);

            //设置从主机读取时间的超时时间
            connection.setReadTimeout(5000);

            //获取请求码（判断网络请求是否正确）
            int code = connection.getResponseCode();

            if (code == HttpURLConnection.HTTP_OK) {

                //如果数据请求成功
                //那就获取数据
                InputStream stream = connection.getInputStream();
                BufferedReader reader = new BufferedReader(new InputStreamReader(stream, "utf-8"));

                //拼接字符串
                StringBuilder builder = new StringBuilder();

                //读取数据转换成字符串
                String str = "";

                while ((str = reader.readLine()) != null) {
                    //拼接成一行数据
                    builder.append(str);
                }
                //返回后拼接数据
                return builder.toString();
            }

            //关闭连接
            connection.disconnect();

        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

**MainActivity页面：开启子线程，写Handler，解析Gson,把数据传递给住线程**

 **3：//点击事件**
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                //开启子线程
                new Thread(){
                    @Override
                    public void run() {
                        super.run();
                        //写耗时操作（请求网络）

                        //判断网络状态
                        boolean notABoolean = Http.isNotABoolean(MainActivity.this);

                        //判断有没网络
                        if (notABoolean){
                            //有网络请求数据
                            String get = Http.requesHttpGet("http://api.expoon.com/AppNews/getNewsList/type/1/p/1");

                            //Gson
                            Gson gson = new Gson();

                            Bean bean = gson.fromJson(get, Bean.class);

                            //把数据传递给住线程
                            Message message = new Message();
                            message.what=0;
                            message.obj=bean;
                            handler.sendMessage(message);
                        }
                        else{
                           handler.sendEmptyMessageDelayed(1,0);
                        }


                    }
                }.start();

            }
        });

**4：写Handler**
Handler handler = new Handler()
    {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what){
                case 0:
                    Bean bean = (Bean) msg.obj;
                    Toast.makeText(MainActivity.this,""+bean.toString(),Toast.LENGTH_LONG).show();
                    break;
                case 1:
                      Toast.makeText(MainActivity.this,"网络中断",Toast.LENGTH_LONG).show();
                    break;
            }
        }
    };

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