在SpringBoot中如何使用HttpClient實(shí)現(xiàn)HTTP請(qǐng)求

更新時(shí)間：2025年02月07日 09:57:00 作者：sco5282

本文介紹了如何使用Apache?HttpClient來訪問HTTP協(xié)議的資源,并提供了詳細(xì)的使用示例,包括GET和POST請(qǐng)求的無參和有參調(diào)用

SpringBoot使用HttpClient實(shí)現(xiàn)HTTP請(qǐng)求

越來越多的 Java 應(yīng)用程序需要直接通過 HTTP 協(xié)議來訪問網(wǎng)絡(luò)資源。雖然在 JDK 的 java.net 包中已經(jīng)提供了訪問 HTTP 協(xié)議的基本功能，但是對(duì)于大部分應(yīng)用程序來說，JDK 庫(kù)本身提供的功能還不夠豐富和靈活。

HttpClient 是 Apache Jakarta Common 下的子項(xiàng)目，用來提供高效的、最新的、功能豐富的支持 HTTP 協(xié)議的客戶端編程工具包，并且它支持 HTTP 協(xié)議最新的版本和建議。

HttpClient 官網(wǎng)

新建一個(gè) SpringBoot 工程，引入 httpclient 的 POM 依賴：

<dependency>
	<groupId>org.apache.httpcomponents</groupId>
	<artifactId>httpclient</artifactId>
	<version>4.5.6</version>
</dependency>

總結(jié)：

public class HttpClientUtil {

    // GET請(qǐng)求
    public static String get(String url, JSONObject params) {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        String sendUrl = url;
        // 拼接參數(shù)
        if (Objects.nonNull(params) && params.size() > 0) {
            sendUrl = connectParams(url, params);
        }
        HttpGet httpGet = new HttpGet(sendUrl);
        CloseableHttpResponse response = null;
        try {
            response = httpClient.execute(httpGet);
            HttpEntity httpEntity = response.getEntity();
            if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode() && null != httpEntity) {
                return EntityUtils.toString(httpEntity);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                close(httpClient, response);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        throw new JeecgBootException("調(diào)用GET請(qǐng)求失??！");
    }

    /**
     * @Description: POST 請(qǐng)求
     * @Author: zzc
     * @Date: 2022-12-16 16:48
     * @param url: 
     * @param params: 
     * @param requestBody: json 串
     * @return: java.lang.String
     **/
    public static String post(String url, JSONObject params, String requestBody) {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        String sendUrl = url;
        // 1.拼接參數(shù)
        if (Objects.nonNull(params) && params.size() > 0) {
            sendUrl = connectParams(url, params);
        }
        HttpPost httpPost = new HttpPost(sendUrl);
        httpPost.setHeader("Content-Type", "application/json;charset=utf8");
        CloseableHttpResponse response = null;
        try {
            // 2.設(shè)置request-body
            if (StringUtils.isNotBlank(requestBody)) {
                ByteArrayEntity entity = new ByteArrayEntity(requestBody.getBytes(StandardCharsets.UTF_8));
                entity.setContentType("application/json");
                httpPost.setEntity(entity);
            }
            response = httpClient.execute(httpPost);
            HttpEntity httpEntity = response.getEntity();
            if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode() && null != httpEntity) {
                return EntityUtils.toString(httpEntity);
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                close(httpClient, response);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        throw new JeecgBootException("調(diào)用POST請(qǐng)求失?。?);
    }

    private static String connectParams(String url, JSONObject params) {
        StringBuffer buffer = new StringBuffer();
        buffer.append(url).append("?");
        params.forEach((x, y) -> buffer.append(x).append("=").append(y).append("&"));
        buffer.deleteCharAt(buffer.length() - 1);
        return buffer.toString();
    }

    public static void close(CloseableHttpClient httpClient, CloseableHttpResponse httpResponse) throws IOException{
        if (null != httpClient) {
            httpClient.close();
        }
        if (null != httpResponse) {
            httpResponse.close();
        }
    }

}

詳細(xì)使用示例

GET 無參

調(diào)用接口：

http://localhost:8080/http/listUsers

沒有入?yún)ⅰ?/p>

HttpClientController#doGetNoParams()：GET請(qǐng)求接口不帶參數(shù)

@RestController
@RequestMapping("/httpClient")
public class HttpClientController {

    @Autowired
    private HttpClientService httpClientService;

    // GET請(qǐng)求接口不帶參數(shù)
    @GetMapping("/doGetNoParams")
    public String doGetNoParams() {
        return httpClientService.doGetNoParams();
    }

}

HttpClientServiceImpl#doGetNoParams()：GET 請(qǐng)求接口不帶參數(shù)

@Slf4j
@Service
public class HttpClientServiceImpl implements HttpClientService {

    // GET請(qǐng)求接口不帶參數(shù)
    @Override
    public String doGetNoParams() {
        String result = HttpClientUtil.doGetNoParams();
        log.info("【發(fā)送GET請(qǐng)求】返回結(jié)果為：{}", result);
        if (!StringUtil.isBlank(result)) {
            TaskCenterUtil taskCenterUtil = TaskCenterUtil.getTaskCenterUtil();
            taskCenterUtil.submitTask(() -> {
                log.info("【子線程】開啟了一個(gè)新線程，當(dāng)前線程名為：{}", Thread.currentThread().getName());
                return null;
            });
        }
        log.info("【主線程】當(dāng)前線程名為：{}", Thread.currentThread().getName());
        return result;
    }

}

說明：

當(dāng) HTTP 調(diào)用成功后，通過線程池開一個(gè)子線程，去異步執(zhí)行任務(wù)；主線程繼續(xù)向下執(zhí)行

HttpClientUtil#doGetNoParams()：GET請(qǐng)求接口不帶參數(shù)

@Slf4j
public class HttpClientUtil {

    // 服務(wù)器ip
    public static final String IP = "http://localhost";

    // 端口
    public static final String PORT = ":8080";

    // GET請(qǐng)求接口不帶參數(shù)
    public static final String GET_URL_NO_PARAMS = IP + PORT + "/http/listUsers";

    // GET請(qǐng)求接口不帶參數(shù)
    public static String doGetNoParams() {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        // 創(chuàng)建 GET 請(qǐng)求
        HttpGet httpGet = new HttpGet(GET_URL_NO_PARAMS);
        httpGet.setHeader("Accept-Encoding", "identity");
        log.info("【發(fā)送GET請(qǐng)求】請(qǐng)求地址為：{}", GET_URL_NO_PARAMS);
        CloseableHttpResponse httpResponse = null;
        try {
            httpResponse = httpClient.execute(httpGet);
            HttpEntity httpEntity = httpResponse.getEntity();
            log.info("【發(fā)送GET請(qǐng)求】成功，相應(yīng)狀態(tài)為：{}", httpResponse.getStatusLine());
            if (HttpStatus.SC_OK == httpResponse.getStatusLine().getStatusCode() && null != httpEntity) {
                String result = EntityUtils.toString(httpEntity);
                log.info("【發(fā)送GET請(qǐng)求】成功，響應(yīng)內(nèi)容為：{}", result);
                return result;
            }
        } catch (IOException e) {
            log.error("【發(fā)送GET請(qǐng)求】失敗，執(zhí)行發(fā)送請(qǐng)求時(shí)，出現(xiàn)IO異常，異常信息為：{}", e);
            return null;
        } finally {
            try {
                close(httpClient, httpResponse);
            } catch (IOException e) {
                log.error("【發(fā)送GET請(qǐng)求】失敗，關(guān)閉流時(shí)，出現(xiàn)IO異常，異常信息為：{}", e);
            }
        }
        return null;
    }

}

說明：

通過類 HttpGet 發(fā)起 GET 請(qǐng)求。

HttpGet：有 3 個(gè)構(gòu)造方法

public class HttpGet extends HttpRequestBase {

    public HttpGet() {
    }

    public HttpGet(URI uri) {
        this.setURI(uri);
    }

    public HttpGet(String uri) {
        this.setURI(URI.create(uri));
    }

    ...
}

這里使用了 public HttpGet(String uri); 方式來構(gòu)造 HttpGet 實(shí)例。

HttpClientUtil#close()：關(guān)閉流

// 關(guān)閉流
public static void close(CloseableHttpClient httpClient, CloseableHttpResponse httpResponse) throws IOException{
    if (null != httpClient) {
        httpClient.close();
    }
    if (null != httpResponse) {
        httpResponse.close();
    }
}

TaskCenterUtil：線程池工具類

public class TaskCenterUtil {

    public static Integer CORE_POOL_SIZE = 10;
    public static Integer MAX_NUM_POOL_SIZE = 10;
    public static Integer MAX_MESSAGE_SIZE = 100;
    public static Long KEEP_ALIVE_TIME = 60L;

    private ThreadPoolExecutor poolExecutor = new ThreadPoolExecutor(CORE_POOL_SIZE, MAX_NUM_POOL_SIZE, KEEP_ALIVE_TIME,
            TimeUnit.SECONDS, new LinkedBlockingQueue<>(MAX_MESSAGE_SIZE), new ThreadPoolExecutor.CallerRunsPolicy());


    private TaskCenterUtil() {}

    private static TaskCenterUtil taskCenterUtil = new TaskCenterUtil();

    public static TaskCenterUtil getTaskCenterUtil() {
        return taskCenterUtil;
    }

    // 提交任務(wù)
    public void submitTask(Callable task) {
        poolExecutor.submit(task);
    }

}

POSTMAN 調(diào)用：

控制臺(tái)打印日志：

GET 有參

方式一：使用 public HttpGet(String uri); 方式來構(gòu)造 HttpGet 實(shí)例。即：使用 url 字符串來拼接參數(shù)。
方式二：使用 public HttpGet(URI uri); 方式來構(gòu)造 HttpGet 實(shí)例。

調(diào)用接口：

http://localhost:8080/http/getUserById?id=1

入?yún)ⅲ?/p>

id=1

HttpClientController#doGetParams()：GET請(qǐng)求接口帶參數(shù)

@GetMapping("/doGetParams")
public String doGetParams(String id) {
    return httpClientService.doGetParams(id);
}

HttpClientServiceImpl：

@Override
public String doGetParams(String id) {
    String result = HttpClientUtil.doGetParams(id);
    log.info("【發(fā)送GET請(qǐng)求】返回結(jié)果為：{}", result);
    return result;
}

HttpClientUtil#doGetParams()：GET請(qǐng)求接口帶參數(shù)

@Slf4j
public class HttpClientUtil {

    // GET請(qǐng)求接口帶參數(shù)
    public static final String GET_URL_PARAMS = IP + PORT + "/http/getUserById";

    // 入?yún)⒚Q
    public static final String URL_PARAMS_ID = "id";
	
	// http 協(xié)議
    public static final String SCHEME_HTTP = "http";

    // 主機(jī)
    public static final String LOCAL_HOST = "localhost";

    // 請(qǐng)求接口路徑
    public static final String GET_URL_PARAMS_PATH = "/http/getUserById";

    // 端口
    public static final Integer LOCAL_PORT = 8080;

    // GET請(qǐng)求接口帶參數(shù)
    public static String doGetParams(String id) {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        // 不同方式獲取 HttpGet
        // 方式一：
        HttpGet httpGet = getStrHttpGet(GET_URL_PARAMS, id);
        // 方式二：
        //HttpGet httpGet = getUrlHttpGet(id);
        // 獲取請(qǐng)求頭配置信息
        RequestConfig requestConfig = HttpClientConfig.getRequestConfig();
        httpGet.setConfig(requestConfig);
        CloseableHttpResponse response = null;
        try {
            response = httpClient.execute(httpGet);
            HttpEntity httpEntity = response.getEntity();
            log.info("【發(fā)送GET請(qǐng)求】成功，相應(yīng)狀態(tài)為：{}", response.getStatusLine());
            if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode() && null != httpEntity) {
                String result = EntityUtils.toString(httpEntity);
                log.info("【發(fā)送GET請(qǐng)求】成功，響應(yīng)內(nèi)容為：{}", result);
                return result;
            }
        } catch (IOException e) {
            log.error("【發(fā)送GET請(qǐng)求】失敗，執(zhí)行發(fā)送請(qǐng)求時(shí)，出現(xiàn)IO異常，異常信息為：{}", e);
            return null;
        } finally {
            try {
                close(httpClient, response);
            } catch (IOException e) {
                log.error("【發(fā)送GET請(qǐng)求】失敗，關(guān)閉流時(shí)，出現(xiàn)IO異常，異常信息為：{}", e);
            }
        }
        return null;
    }
}

getStrHttpGet()：方式一：url拼接參數(shù)

public static HttpGet getStrHttpGet(String url, String id) {
    StringBuilder builder = new StringBuilder();
    // url 拼接參數(shù)  /http/getUserById?id=1
    String strUrl = builder.append(url).append("?").append(URL_PARAMS_ID).append("=").append(id).toString();
    log.info("【發(fā)送GET請(qǐng)求】請(qǐng)求地址為：{}", strUrl);
    HttpGet httpGet = new HttpGet(strUrl);
    return httpGet;
}

getUrlHttpGet()：方式二：URI對(duì)象

public static HttpGet getUrlHttpGet(String id) {
    // 將參數(shù)鍵值對(duì)放入集合中
    List<NameValuePair> params = new ArrayList<>();
    params.add(new BasicNameValuePair(URL_PARAMS_ID, id));
    try {
        URI uri = new URIBuilder()
                .setScheme(SCHEME_HTTP)
                .setHost(LOCAL_HOST)
                .setPort(LOCAL_PORT)
                .setPath(GET_URL_PARAMS_PATH)
                .setParameters(params).build();
        return new HttpGet(uri);
    } catch (URISyntaxException e) {
        log.error("【發(fā)送GET請(qǐng)求】構(gòu)建URI失敗，失敗信息為：{}", e);
    }
    return null;
}

說明：

方式一是使用 public HttpGet(String uri); 方式來構(gòu)造 HttpGet 實(shí)例
方式二是使用 public HttpGet(URL uri); 方式來構(gòu)造 HttpGet 實(shí)例。即：使用 url 字符串來拼接參數(shù)。

POSTMAN 調(diào)用：

POST 無參

調(diào)用接口：

http://localhost:8080/http/listUserList

入?yún)ⅲ簾o

HttpClientController#doPostNoParams()：POST請(qǐng)求接口不帶參數(shù)

@PostMapping("/doPostNoParams")
public String doPostNoParams() {
    return httpClientService.doPostNoParams();
}

HttpClientServiceImpl#doPostNoParams()：

@Override
public String doPostNoParams() {
    String result = HttpClientUtil.doPostNoParams();
    log.info("【發(fā)送POST請(qǐng)求】返回結(jié)果為：{}", result);
    return result;
}

HttpClientUtil：

public class HttpClientUtil {

    // POST請(qǐng)求接口不帶參數(shù)
    public static final String POST_URL_NO_PARAMS = IP + PORT + "/http/listUserList";
	
	// POST請(qǐng)求接口帶參數(shù)
    public static final String POST_URL_PARAMS = IP + PORT + "/http/getUserVoById";

    // POST請(qǐng)求接口帶參數(shù) -- 對(duì)象參數(shù)
    public static final String POST_URL_PARAMS_OBJECT = IP + PORT + "/http/listUsers";

    // POST請(qǐng)求接口不帶參數(shù)
    public static String doPostNoParams() {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        HttpPost httpPost = new HttpPost(POST_URL_NO_PARAMS);
        log.info("【發(fā)送POST請(qǐng)求】請(qǐng)求地址為：{}", POST_URL_NO_PARAMS);
        CloseableHttpResponse response = null;
        try {
            response = httpClient.execute(httpPost);
            HttpEntity httpEntity = response.getEntity();
            log.info("【發(fā)送POST請(qǐng)求】成功，相應(yīng)狀態(tài)為：{}", response.getStatusLine());
            if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode() && null != httpEntity) {
                String result = EntityUtils.toString(httpEntity);
                log.info("【發(fā)送POST請(qǐng)求】成功，響應(yīng)內(nèi)容為：{}", result);
                return result;
            }
        } catch (IOException e) {
            log.error("【發(fā)送POST請(qǐng)求】失敗，執(zhí)行發(fā)送請(qǐng)求時(shí)，出現(xiàn)IO異常，異常信息為：{}", e);
            return null;
        } finally {
            try {
                close(httpClient, response);
            } catch (IOException e) {
                log.error("【發(fā)送POST請(qǐng)求】失敗，關(guān)閉流時(shí)，出現(xiàn)IO異常，異常信息為：{}", e);
            }
        }
        return null;
    }

}

POST 有參

參數(shù)是：普通參數(shù)。方式與GET一樣即可，直接在 url 后綴上拼接參數(shù)
參數(shù)是：對(duì)象。將參數(shù)以請(qǐng)求體 request-body 的方式進(jìn)行請(qǐng)求
參數(shù)是：普通參數(shù)+對(duì)象。普通參數(shù) 直接在 url 后綴上拼接參數(shù)；對(duì)象以請(qǐng)求體 request-body 的方式進(jìn)行請(qǐng)求

普通參數(shù)

請(qǐng)求接口：

http://localhost:8080/http/getUserVoById?id=1

對(duì)象參數(shù)

請(qǐng)求接口：

http://localhost:8080/http/listUsers

入?yún)?UserVo：

{
	"id": 1
}

即：這個(gè)接口可以隨便寫

@PostMapping("/listUsers")
public List<UserVo> listUsers(@RequestBody UserVo userVo) {
    return httpService.listUsers();
}

HttpClientController#doPostParams()：POST請(qǐng)求接口帶參數(shù)

@PostMapping("/doPostParams")
public String doPostParams(String id) {
    return httpClientService.doPostParams(id);
}

HttpClientServiceImpl#doPostParams()：

@Override
public String doPostParams(String id) {
    String result = HttpClientUtil.doPostParams(id);
    log.info("【發(fā)送POST請(qǐng)求】返回結(jié)果為：{}", result);
    return result;
}

HttpClientUtil#doPostParams()：

public static String doPostParams(String id) {
    CloseableHttpClient httpClient = HttpClientBuilder.create().build();
    // 參數(shù)是普通參數(shù)
    HttpPost httpPost = getStrHttpPost(POST_URL_PARAMS, id);
    // 參數(shù)是對(duì)象
    //HttpPost httpPost = getObjectHttpPost(id);
    // 設(shè)置ContentType(注:如果只是傳普通參數(shù)的話,ContentType不一定非要用application/json)
    httpPost.setHeader("Content-Type", "application/json;charset=utf8");
    CloseableHttpResponse response = null;
    try {
        response = httpClient.execute(httpPost);
        HttpEntity httpEntity = response.getEntity();
        log.info("【發(fā)送POST請(qǐng)求】成功，相應(yīng)狀態(tài)為：{}", response.getStatusLine());
        if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode() && null != httpEntity) {
            String result = EntityUtils.toString(httpEntity);
            log.info("【發(fā)送POST請(qǐng)求】成功，響應(yīng)內(nèi)容為：{}", result);
            return result;
        }
    } catch (IOException e) {
        log.error("【發(fā)送POST請(qǐng)求】失敗，執(zhí)行發(fā)送請(qǐng)求時(shí)，出現(xiàn)IO異常，異常信息為：{}", e);
        return null;
    } finally {
        try {
            close(httpClient, response);
        } catch (IOException e) {
            log.error("【發(fā)送POST請(qǐng)求】失敗，關(guān)閉流時(shí)，出現(xiàn)IO異常，異常信息為：{}", e);
        }
    }
    return null;
}

getStrHttpPost()：POST請(qǐng)求有參：普通參數(shù)

public static HttpPost getStrHttpPost(String url, String id) {
    StringBuilder builder = new StringBuilder();
    // url 拼接參數(shù)  /http/getUserVoById?id=1
    String strUrl = builder.append(url).append("?").append(URL_PARAMS_ID).append("=").append(id).toString();
    log.info("【發(fā)送POST請(qǐng)求】請(qǐng)求地址為：{}", strUrl);
    HttpPost httpPost = new HttpPost(strUrl);
    return httpPost;
}

getObjectHttpPost()：POST請(qǐng)求有參：對(duì)象參數(shù)

public static HttpPost getObjectHttpPost(String id) {
    HttpPost httpPost = new HttpPost(POST_URL_PARAMS_OBJECT);
    log.info("【發(fā)送POST請(qǐng)求】請(qǐng)求地址為：{}", POST_URL_PARAMS_OBJECT);
    UserVo userVo = new UserVo();
    userVo.setId(id);
    // 將JAVA對(duì)象轉(zhuǎn)換為Json字符串
    String jsonString = JSON.toJSONString(userVo);
    StringEntity stringEntity = new StringEntity(jsonString, "UTF-8");
    // post請(qǐng)求是將參數(shù)放在請(qǐng)求體里面?zhèn)鬟^去的
    httpPost.setEntity(stringEntity);
    return httpPost;
}

普通參數(shù) + 對(duì)象

// params：name=zzc&age=17  marshal:json 串
public static String post(String url, String params, String marshal) {
    CloseableHttpClient httpClient = HttpClientBuilder.create().build();
    String strUrl = url + "?" + params;
    HttpPost httpPost = new HttpPost(strUrl);
    httpPost.setHeader("Content-Type", "application/json;charset=utf8");

    CloseableHttpResponse response = null;
    try {
        // 設(shè)置 requst-body 參數(shù)
        ByteArrayEntity entity = new ByteArrayEntity(marshal.getBytes("UTF-8"));
        entity.setContentType("application/json");
        httpPost.setEntity(entity);

        response = httpClient.execute(httpPost);
        HttpEntity httpEntity = response.getEntity();
        if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode() && null != httpEntity) {
            String result = EntityUtils.toString(httpEntity);
            return result;
        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            close(httpClient, response);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return null;
}

表單提交

public static String post(String url, Map<String, String> params) {
    CloseableHttpClient httpClient = HttpClientBuilder.create().build();
    HttpPost httpPost = new HttpPost(url);
    httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded");
    // 參數(shù)
    List<NameValuePair> nameValuePairs = new ArrayList<>();
    if (MapUtils.isNotEmpty(params)) {
        params.forEach((x, y) -> {
            nameValuePairs.add(new BasicNameValuePair(x, y));
        });
    }
    CloseableHttpResponse response = null;
    try {
        httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
        response = httpClient.execute(httpPost);
        HttpEntity httpEntity = response.getEntity();
        if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode() && null != httpEntity) {
            return EntityUtils.toString(httpEntity);
        }
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            close(httpClient, response);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    throw new JeecgBootException("調(diào)用accessToken API失敗");
}