温湿度项目--Android APP_android实现温湿度采集

添加网络权限
<uses-permission android:name="android.permission.INTERNET" />
导入 OkHttp3 依赖库
在 Module 下的 build.gradle 配置文件中的 dependencies 节点 , 进行如下配置 ;
implementation 'com.squareup.okhttp3:okhttp:3.12.0'
非https报错的的处理办法
CLEARTEXT communication to 121.4.99.98 not permitted by network security policy
在AndroidManifest.xml application  添加 android:usesCleartextTraffic="true"

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout  xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    tools:context=".MainActivity"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
 
    <Button
        android:text="获取数据"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:id="@+id/getData" />
 
    <TextView
        android:id="@+id/content"
        android:layout_width="match_parent"
        android:layout_height="500dp"
        android:background="#456789"/>
 
</LinearLayout>
 

package com.example.wsd;
 
import androidx.appcompat.app.AppCompatActivity;
 
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
 
import org.json.JSONArray;
import org.json.JSONObject;
 
import java.io.IOException;
 
import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
 
public class MainActivity extends AppCompatActivity {
    private Button btn;
    private TextView content;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn = findViewById(R.id.getData);
        content = findViewById(R.id.content);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //第一步获取okHttpClient对象
                OkHttpClient client = new OkHttpClient.Builder()
                        .build();
                //第二步构建Request对象
                Request request = new Request.Builder()
                        .url("http://121.4.99.98:5000?num=30")
                        .get()
                        .build();
                //第三步构建Call对象
                Call call = client.newCall(request);
                //第四步:异步get请求
                call.enqueue(new Callback() {
                    @Override
                    public void onFailure(Call call, IOException e) {
                        Log.i("onFailure", e.getMessage());
                    }
                    @Override
                    public void onResponse(Call call, Response response) throws IOException {
                        String result = response.body().string(); // [[7654,"21.80","94.00","2022-11-19 19:21:54"],[7653,"21.70","94.00","2022-11-19 19:21:44"]]
                        content.setText(result);
                    }
                });
            }
        });
    }
}