Spring Boot与HttpClient：轻松实现GET和POST请求(2)

Spring

1.3 HttpClient的maven坐标

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.13</version>
</dependency>

1.4. HttpClient的核心API

• HttpClient：Http客户端对象类型，使用该类型对象可发起Http请求。
• HttpClients：可认为是构建器，可创建HttpClient对象。
• CloseableHttpClient：实现类，实现了HttpClient接口。
• HttpGet：Get请求类型。
• HttpPost：Post请求类型。

1.5. HttpClient发送请求步骤

• 创建HttpClient对象
• 创建Http请求对象
• 调用HttpClient的execute方法发送请求

2. SpringBoot快速入门HttpClient

对HttpClient编程工具包有了一定了解后，那么，我们使用HttpClient在Java程序当中来构造Http的请求，并且把请求发送出去，接下来，就通过入门案例分别发送GET请求和POST请求，具体来学习一下它的使用方法。

项目结构

创建HttpClient-demo,并导入对应依赖到pom.xml

• 完整项目结果

• pom.xml 依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <artifactId>spring-boot-starter-parent</artifactId>
        <groupId>org.springframework.boot</groupId>
        <version>2.7.15</version>
    </parent>
    <groupId>com.zbbmeta</groupId>
    <artifactId>HttpClient-demo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
        <dependency>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>knife4j-spring-boot-starter</artifactId>
            <version>3.0.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.13</version>
        </dependency>
    </dependencies>
</project>

2.1.GET方式请求

实现步骤：

1. 创建HttpClient对象
2. 创建请求对象
3. 发送请求，接受响应结果
4. 解析结果
5. 关闭资源

在com.zbbmeta.controller包下创建HttpClientController接口类，并创建testGET()方法

package com.zbbmeta.controller;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicHeader;
import org.apache.http.util.EntityUtils;
import org.junit.jupiter.api.Test;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.Arrays;
/**
 * @author springboot葵花宝典
 * @description: TODO
 */
@RestController
@RequestMapping(value = "/httpclient")
@Slf4j
@Api(tags = "HttpClient测试接口")
public class HttpClientController {
   
    @GetMapping("/httpget")
    @ApiOperation(value = "http员工状态")
    public String testGET() throws Exception{
        //创建httpclient对象
       CloseableHttpClient httpClient = HttpClients.createDefault();
       
        //创建请求对象
        HttpGet httpGet = new HttpGet("http://localhost:8899/admin/employee/status");
        
        //发送请求，接受响应结果
        CloseableHttpResponse response = httpClient.execute(httpGet);
        //获取服务端返回的状态码
        int statusCode = response.getStatusLine().getStatusCode();
        System.out.println("服务端返回的状态码为：" + statusCode);
        HttpEntity entity = response.getEntity();
        String body = EntityUtils.toString(entity);
        System.out.println("服务端返回的数据为：" + body);
        //关闭资源
        response.close();
        httpClient.close();
        return "服务端返回的数据为：" + body;
    }n "服务端返回的数据为：" + body;
    }
}

启动项目，PostMan访问http://localhost:8899/httpclient/httpget请求

测试结果

2.2. POST方式请求

在HttpClientTest中添加POST方式请求方法，相比GET请求来说，POST请求若携带参数需要封装请求体对象，并将该对象设置在请求对象中。

实现步骤：

1. 创建HttpClient对象
2. 创建请求对象
3. 发送请求，接收响应结果
4. 解析响应结果
5. 关闭资源

在com.zbbmeta.controller包下创建HttpClientController接口类，并创建testPost()方法

 @PostMapping("/httppost")
    @ApiOperation(value = "http员工登录")
    public String testPost() throws Exception{
        //创建httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //创建请求对象
        HttpPost httpPost = new HttpPost("http://localhost:8899/admin/employee/login");
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("username","admin");
        jsonObject.put("password","123456");
        StringEntity entity = new StringEntity(jsonObject.toString());
        //指定请求编码方式
        entity.setContentEncoding("utf-8");
        //数据格式
        entity.setContentType("application/json");
        httpPost.setEntity(entity);
        //发送请求
        CloseableHttpResponse response = httpClient.execute(httpPost);
        //解析返回结果
        int statusCode = response.getStatusLine().getStatusCode();
        System.out.println("响应码为：" + statusCode);
        HttpEntity entity1 = response.getEntity();
        String body = EntityUtils.toString(entity1);
        System.out.println("响应数据为：" + body);
        //关闭资源
        response.close();
        httpClient.close();
        return  body;
    }

测试结果

以上就是Spring、Boot与HttpClient 及其 轻松实现GET和POST请求的全面介绍了，希望给IT袋网网的网友们带来一些相关知识。