OkHttp3网络请求工具类

//添加依赖

com.squareup.okhttp3:okhttp:3.9.0                                                                                  

public class OKHttpUtil {
    //3.提供该类对象的常量
    private static OKHttpUtil okHttpUtil;
    public static OkHttpClient okHttpClient;

    //1.私有化构造函数
    private OKHttpUtil() {
        okHttpClient = new OkHttpClient();
    }

    //2.提供公有静态方法返回一个该类的实例对象
    //懒汉式
    public static OkHttpClient getInstance() {
        if (null == okHttpUtil) {
            synchronized (OKHttpUtil.class) {
                if (null == okHttpUtil) {
                    okHttpUtil = new OKHttpUtil();
                }
            }
        }
        return okHttpClient;
    }

    public static void get(String urlString, Callback callback){
        //利用参数传递形式，传递请求地址
        Request request = new Request.Builder().get().url(urlString).build();
        //挂载到请求队列中
        okHttpClient.newCall(request).enqueue(callback);
    }

    public static void post(String urlString, RequestBody requestBody,Callback callback){
        Request request = new Request.Builder().url(urlString).method("POST", requestBody).build();
        //挂载到请求队列中
        okHttpClient.newCall(request).enqueue(callback);
    }
}