（1）maven 依赖：
<!-- HttpClinet 核心包 --><dependency><groupId>org.apache.httpcomponents</groupId><artifactId>httpclient</artifactId><version>4.5.13</version></dependency><!-- HttpClinet 请求时，涉及文件上传需要的包 --><dependency><groupId>org.apache.httpcomponents</groupId><artifactId>httpmime</artifactId><version>4.5.13</version></dependency>
（ 2 ）工具类代码
package com.unisoc.releaseCenter.utils;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.UnsupportedEncodingException;import java.util.ArrayList;import java.util.List;import java.util.Map;import java.util.Map.Entry;import java.util.Objects;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPost;import org.apache.http.client.methods.HttpUriRequest;import org.apache.http.entity.ContentType;import org.apache.http.entity.StringEntity;import org.apache.http.entity.mime.MultipartEntityBuilder;import org.apache.http.entity.mime.content.FileBody;import org.apache.http.entity.mime.content.StringBody;import org.apache.http.impl.client.HttpClients;import org.apache.http.message.BasicNameValuePair;/*** HttpClient工具类** @author ZhangYuanqiang* @since -06-10*/public class HttpUtils {/*** 字符编码*/private final static String UTF8 = "utf-8";/*** 字节流数组大小（1MB）*/private final static int BYTE_ARRAY_LENGTH = 1024 * 1024;/*** 执行get请求获取响应** @param url 请求地址* @return 响应内容*/public static String get(String url) {return get(url, null);}/*** 执行get请求获取响应** @param url请求地址* @param headers 请求头参数* @return 响应内容*/public static String get(String url, Map<String, String> headers) {HttpGet get = new HttpGet(url);return getRespString(get, headers);}/*** 执行post请求获取响应** @param url 请求地址* @return 响应内容*/public static String post(String url) {return post(url, null, null);}/*** 执行post请求获取响应** @param url 请求地址* @param params 请求参数* @return 响应内容*/public static String post(String url, Map<String, String> params) {return post(url, null, params);}/*** 执行post请求获取响应** @param url请求地址* @param headers 请求头参数* @param params 请求参数* @return 响应内容*/public static String post(String url, Map<String, String> headers, Map<String, String> params) {HttpPost post = new HttpPost(url);post.setEntity(getHttpEntity(params));return getRespString(post, headers);}/*** 执行post请求获取响应（请求体为JOSN数据）** @param url 请求地址* @param json 请求的JSON数据* @return 响应内容*/public static String postJson(String url, String json) {return postJson(url, null, json);}/*** 执行post请求获取响应（请求体为JOSN数据）** @param url请求地址* @param headers 请求头参数* @param json 请求的JSON数据* @return 响应内容*/public static String postJson(String url, Map<String, String> headers, String json) {HttpPost post = new HttpPost(url);post.setHeader("Content-type", "application/json");post.setEntity(new StringEntity(json, UTF8));return getRespString(post, headers);}/*** 执行post请求获取响应（请求体包含文件）** @param url 请求地址* @param params 请求参数（文件对应的value传File对象）* @return 响应内容*/public static String postFile(String url, Map<String, Object> params) {return postFile(url, null, params);}/*** 执行post请求获取响应（请求体包含文件）** @param url请求地址* @param headers 请求头参数* @param params 请求参数（文件对应的value传File对象）* @return 响应内容*/public static String postFile(String url, Map<String, String> headers, Map<String, Object> params) {HttpPost post = new HttpPost(url);MultipartEntityBuilder builder = MultipartEntityBuilder.create();if (Objects.nonNull(params) && !params.isEmpty()) {for (Entry<String, Object> entry : params.entrySet()) {String key = entry.getKey();Object value = entry.getValue();if (Objects.isNull(value)) {builder.addPart(key, new StringBody("", ContentType.TEXT_PLAIN));} else {if (value instanceof File) {builder.addPart(key, new FileBody((File) value));} else {builder.addPart(key, new StringBody(value.toString(), ContentType.TEXT_PLAIN));}}}}HttpEntity entity = builder.build();post.setEntity(entity);return getRespString(post, headers);}/*** 下载文件** @param url下载地址* @param path保存路径（如：D:/images，不传默认当前工程根目录）* @param fileName 文件名称（如：hello.jpg）*/public static void download(String url, String path, String fileName) {HttpGet get = new HttpGet(url);File dir = new File(path);if (!dir.exists()) {dir.mkdirs();}String filePath = null;if (Objects.isNull(path) || path.isEmpty()) {filePath = fileName;} else {if (path.endsWith("/")) {filePath = path + fileName;} else {filePath += path + "/" + fileName;}}File file = new File(filePath);if (!file.exists()) {try {file.createNewFile();} catch (IOException e) {e.printStackTrace();}}try (FileOutputStream fos = new FileOutputStream(file); InputStream in = getRespInputStream(get, null)) {if (Objects.isNull(in)) {return;}byte[] bytes = new byte[BYTE_ARRAY_LENGTH];int len = 0;while ((len = in.read(bytes)) != -1) {fos.write(bytes, 0, len);}} catch (Exception e) {e.printStackTrace();}}/*** 获取请求体HttpEntity** @param params 请求参数* @return HttpEntity*/private static HttpEntity getHttpEntity(Map<String, String> params) {List<BasicNameValuePair> pairs = new ArrayList<BasicNameValuePair>();for (Entry<String, String> entry : params.entrySet()) {pairs.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));}HttpEntity entity = null;try {entity = new UrlEncodedFormEntity(pairs, UTF8);} catch (UnsupportedEncodingException e) {e.printStackTrace();}return entity;}/*** 设置请求头** @param request 请求对象* @param headers 请求头参数*/private static void setHeaders(HttpUriRequest request, Map<String, String> headers) {if (Objects.nonNull(headers) && !headers.isEmpty()) {// 请求头不为空，则设置对应请求头for (Entry<String, String> entry : headers.entrySet()) {request.setHeader(entry.getKey(), entry.getValue());}} else {// 请求为空时，设置默认请求头request.setHeader("Connection", "keep-alive");request.setHeader("Accept-Encoding", "gzip, deflate, br");request.setHeader("Accept", "*/*");request.setHeader("User-Agent","Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.135 Safari/537.36");}}/*** 执行请求，获取响应流** @param request 请求对象* @return 响应内容*/private static InputStream getRespInputStream(HttpUriRequest request, Map<String, String> headers) {// 设置请求头setHeaders(request, headers);// 获取响应对象HttpResponse response = null;try {response = HttpClients.createDefault().execute(request);} catch (Exception e) {e.printStackTrace();return null;}// 获取Entity对象HttpEntity entity = response.getEntity();// 获取响应信息流InputStream in = null;if (Objects.nonNull(entity)) {try {in = entity.getContent();} catch (Exception e) {e.printStackTrace();}}return in;}/*** 执行请求，获取响应内容** @param request 请求对象* @return 响应内容*/private static String getRespString(HttpUriRequest request, Map<String, String> headers) {byte[] bytes = new byte[BYTE_ARRAY_LENGTH];int len = 0;try (InputStream in = getRespInputStream(request, headers);ByteArrayOutputStream bos = new ByteArrayOutputStream()) {if (Objects.isNull(in)) {return "";}while ((len = in.read(bytes)) != -1) {bos.write(bytes, 0, len);}return bos.toString(UTF8);} catch (Exception e) {e.printStackTrace();}return "";}}
