java实现HttpClient请求

1. pom.xml中添加Commons-httpclient包

<dependency>
    <groupId>commons-httpclientgroupId>
    <artifactId>commons-httpclientartifactId>
    <version>3.1version>
dependency>

<dependency>
    <groupId>com.alibabagroupId>
    <artifactId>fastjsonartifactId>
    <version>1.2.32version>
dependency>

2. Http请求工具类

import com.alibaba.fastjson.JSONObject;
import org.apache.commons.httpclient.*;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.StringRequestEntity;
import org.apache.commons.httpclient.params.HttpMethodParams;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/**
 * Http请求工具类
 * @author kxz
 * @date 2022/7/13
 */
public class HttpClientUtil {
    /**
     * httpClient的get请求方式
     * 使用GetMethod来访问一个URL对应的网页实现步骤：
     * 1.生成一个HttpClient对象并设置相应的参数；
     * 2.生成一个GetMethod对象并设置响应的参数；
     * 3.用HttpClient生成的对象来执行GetMethod生成的Get方法；
     * 4.处理响应状态码；
     * 5.若响应正常，处理HTTP响应内容；
     * 6.释放连接。
     * @param url
     * @param charset
     * @return
     */
    public static String doGet(String url, String charset) {
        //1.生成HttpClient对象并设置参数
        HttpClient httpClient = new HttpClient();
        //设置Http连接超时为5秒
        httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(5000);
        //2.生成GetMethod对象并设置参数
        GetMethod getMethod = new GetMethod(url);
        //设置get请求超时为5秒
        getMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 5000);
        //设置请求重试处理，用的是默认的重试处理：请求三次
        getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler());
        String response = "";
        //3.执行HTTP GET 请求
        try {
            int statusCode = httpClient.executeMethod(getMethod);
            //4.判断访问的状态码
            if (statusCode != HttpStatus.SC_OK) {
                System.err.println("请求出错：" + getMethod.getStatusLine());
            }

            //5.处理HTTP响应内容
            //HTTP响应头部信息，这里简单打印
            //  Header[] headers = getMethod.getResponseHeaders();
            //  for(Header h : headers) {
            //      System.out.println(h.getName() + "---------------" + h.getValue());
            //  }

            //读取HTTP响应内容，这里简单打印网页内容
            //读取为字节数组
            byte[] responseBody = getMethod.getResponseBody();
            response = new String(responseBody, charset);
//            System.out.println("-----------response:" + response);
            //读取为InputStream，在网页内容数据量大时候推荐使用
            //InputStream response = getMethod.getResponseBodyAsStream();
        } catch (HttpException e) {
            //发生致命的异常，可能是协议不对或者返回的内容有问题
            System.out.println("请检查输入的URL!");
            e.printStackTrace();
        } catch (IOException e) {
            //发生网络异常
            System.out.println("发生网络异常!");
        } finally {
            //6.释放连接
            getMethod.releaseConnection();
        }
        return response;
    }

    /**
     * post请求
     * @param url
     * @param jsonObject
     * @return
     */
    public static String doPost(String url, JSONObject jsonObject){
        HttpClient httpClient = new HttpClient();
        PostMethod postMethod = new PostMethod(url);

        postMethod.addRequestHeader("accept", "*/*");
        postMethod.addRequestHeader("connection", "Keep-Alive");
        //设置json格式传送
        postMethod.addRequestHeader("Content-Type", "application/json;charset=utf-8");
        //必须设置下面这个Header
        postMethod.addRequestHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36");
        //添加请求参数-方式一
        //此处是以json对象格式作为参数请求，同postman中Body=》raw=》JSON格式。
        //例如：{"webankAppId":"TIDAXT3h","orderNo":"orderNo371521199209186112_1", "name":"孔祥宗", "idNo":"371521199209186112", "userId":"userID371521199209186112_1", "version":"1.0.0", "sign":"98B985A1314D720AD16BFE53B1A5005C66E3D8E1"}
        postMethod.setRequestEntity(new StringRequestEntity(jsonObject.toString()));
        //添加请求参数-方式二、三略


        String res = "";
        try {
            int code = httpClient.executeMethod(postMethod);
            if (code == 200){
                res = postMethod.getResponseBodyAsString();
                System.out.println(res);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return res;
    }

    public static void main(String[] args) {
        Map<String, String> params = new HashMap<>();
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("webankAppId", FaceConfig.APP_ID);
        jsonObject.put("name", "name");
        jsonObject.put("orderNo", "orderNo");
        jsonObject.put("idNo", "idCard");
        jsonObject.put("userId", "userId");
        jsonObject.put("version", "name");
        jsonObject.put("sign", "sign");
        String h5faceidResult = HttpClientUtil.doPost("https://miniprogram-kyc.tencentcloudapi.com/api/server/h5/geth5faceid", jsonObject);
        System.out.println(h5faceidResult);
    }
}