一、毫无疑问，添加依赖

我用的是这个版本

implementation 'com.squareup.okhttp3:okhttp:4.0.0'

二、来一个客户端（okhttpclient）

OkHttpClient client = new OkHttpClient.Builder().build();

三、来一个请求（request）

Request request = new Request.Builder()
                .get()
                .url("http://dasai.sdvcst.edu.cn:8080/press/press/list?pageNum=1&pageSize=10")
                .build();

四、关联客户端与请求

client.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(@NotNull Call call, @NotNull IOException e) {
                e.printStackTrace();
            }
            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                String string = response.body().string();
                Message msg = Message.obtain();
                msg.what=1;
                msg.obj=string;
                handler.sendMessage(msg);
            }
        });

五、通过handlersend将信息发到主线程，所以要一个handler

六、在handler里面处理信息

    Handler handler = new Handler(){
        @Override
        public void handleMessage(@NonNull Message msg) {
            super.handleMessage(msg);
            switch (msg.what){
                case 1:
                    String result = (String) msg.obj;
                    Gson gson = new Gson();
                    NewsBean bean = gson.fromJson(result, NewsBean.class);
                    adapter = new MyListAdapter(ListView.this, bean.getRows());
                    my_listview.setAdapter(adapter);
                    Log.e("wwwwwwwwwwwwwwwww", "handleMessage: \n"+result );
                    break;
            }
        }
    };

七、post请求则需要一个requestbody，requestbody里面需要两个参数，一个json数据，一个mediatype

image.png

OkHttpClient client = new OkHttpClient.Builder().build();
        loginBean bean = new loginBean();
        bean.setUsername("111");
        bean.setPassword("111");
        Gson gson = new Gson();
        String toJson = gson.toJson(bean);
        MediaType mediaType = MediaType.parse("application/json");
        RequestBody body = RequestBody.create(mediaType, toJson);
        Request request = new Request.Builder()
                .post(body)
                .url("http://dasai.sdvcst.edu.cn:8080/login")
                .build();

PS：解析数据用的gson