网络请求三方库——OkHttp

/**
 * Created by SteveWang on 2016/7/28.
 */
public class OkHttpUtils
{
    private static final OkHttpClient okHttpClient = new OkHttpClient();
    public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");

    /**
     * GET方式同步请求网络，服务器端返回JSON格式的字符串
     * @param urlString
     * @return
     * @throws IOException
     */
    public static String getStringFromURL(String urlString) throws IOException
    {
        // 1. 获取Request对象
        Request request = new Request.Builder()
                .url(urlString)
                .build();
        // 2. 获取Response对象
        Response response = okHttpClient.newCall(request).execute();
        // 3. 获取ResponseBody对象
        ResponseBody responseBody = response.body();
        if(responseBody != null)
        {
            // 4. 从ResponseBody对象中获取服务器端返回数据
            return responseBody.string();
        }
        return null;
    }

    /**
     * POST方式同步请求网络，向服务器端提交JSON格式的请求，服务器端返回JSON格式的字符串
     * @param urlString
     * @param jsonRequest
     * @return
     * @throws IOException
     */
    public static  String postJsonToURL(String urlString, String jsonRequest) throws IOException
    {
        // 1. 首先构造RequestBody对象，指定了MediaType为JSON
        RequestBody requestBody = RequestBody.create(JSON, jsonRequest);
        // 2. 获取Request对象，将RequestBody放置到Request对象中
        Request request = new Request.Builder()
                .url(urlString)
//                .addHeader(name, value)   // 添加请求头
                .post(requestBody)
                .build();
        // 3. 获取Response对象
        Response response = okHttpClient.newCall(request).execute();
        // 4. 获取ResponseBody对象,从中获取服务器返回的JSON数据
        return response.body().string();
    }
}