添加依赖

<dependency>
    <groupId>com.squareup.okhttp3</groupId>
    <artifactId>okhttp</artifactId>
    <version>5.0.0-alpha.11</version>
</dependency>

发送get请求

public static <T> T getRequest(String url, Map<String,String> params,Class<T> tClass){
        //超时时间为30s
        OkHttpClient client = new OkHttpClient.Builder()
                .connectTimeout(30, TimeUnit.SECONDS).build();
        HttpUrl.Builder httpBuilder  = HttpUrl.parse(url).newBuilder();
        if (params!=null){
            params.forEach((k,v)->httpBuilder.addQueryParameter(k,v));
        }
        Request request = new Request.Builder()
                .url(httpBuilder.build())
                .get()
                .addHeader("Content-Type", "application/x-www-form-urlencoded")
                .build();
        try {
            Response response = client.newCall(request).execute();
            if (response.isSuccessful()){
                System.out.println("响应结果:"+response.body().string());
                return JSON.parseObject(response.body().string(),tClass);
            }else {
                throw new IOException("Unexpected code "+response);
            }
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

    }

发送post请求，参数为json格式

public static <T> T postRequest(String url, Map<String,String> params,Class<T> tClass){
       OkHttpClient client = new OkHttpClient.Builder()
                .connectTimeout(30, TimeUnit.SECONDS).build();
        MediaType type = MediaType.parse("application/json;charset=utf-8");
        JSONObject json = new JSONObject();
        if (params!=null){
            params.forEach((k,v)->json.put(k,v));
        }
        RequestBody requestBody = RequestBody.create(type, String.valueOf(json));
        Request request = new Request.Builder()
                .url(url)
                .post(requestBody)
                .addHeader("Content-Type", "application/json;charset=utf-8")
                .build();
        try {
            Response response = client.newCall(request).execute();
            if (response.isSuccessful()){
                System.out.println("响应结果:"+response.body().string());
                return JSON.parseObject(response.body().string(),tClass);
            }else {
                throw new IOException("Unexpected code "+response);
            }
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }