在Java中，使用HttpUtils实现发送HTTP请求

HTTP请求，在日常开发中，还是比较常见的，今天给大家分享HttpUtils如何使用。

阅读本文，你将收获：

简单总结HTTP请求常用配置；
JavaLib中HttpUtils如何使用；
如何封装HTTP请求工具类。

第一部分：简单总结HTTP请求常用配置

大家好，在 Java 开发中，经常遇到需要调用第三方提供的接口服务，常见的形式是 HTTP + JSON，下面，就对 http 请求常见的设置，做一个说明

http提供多种请求方式，以满足我们日常需要，先按请求方式来做说明：

GET
POST
PUT
PATCH
DELETE

在 RESTful API 开发中，我们可以根据这些请求方式设计我们的API接口。举例：

GET：获取资源
POST：提交资源
PUT：更新完整资源
PATCH：更新部分资源
DELETE：删除资源

参数格式

form表单
json

其他

超时时间设置

第二部分：使用JavaLib的HttpUtils

简单的get请求

System.out.println(HttpUtils.get("https://www.baidu.com"));

响应结果：

<!DOCTYPE html><!--STATUS OK--><html> <head><meta http-equiv=content-type content=text/html;charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=always name=referrer><link rel=stylesheet type=text/css href=https://ss1.bdstatic.com/5eN1bjq8AAUYm2zgoY3K/r/www/cache/bdorz/baidu.min.css><title>百度一下，你就知道</title></head> <body link=#0000cc> <div id=wrapper> <div id=head> <div class=head_wrapper> <div class=s_form> <div class=s_form_wrapper> <div id=lg> <img hidefocus=true src=//www.baidu.com/img/bd_logo1.png width=270 height=129> </div> <form id=form name=f action=//www.baidu.com/s class=fm> <input type=hidden name=bdorz_come value=1> <input type=hidden name=ie value=utf-8> <input type=hidden name=f value=8> <input type=hidden name=rsv_bp value=1> <input type=hidden name=rsv_idx value=1> <input type=hidden name=tn value=baidu><span class="bg s_ipt_wr"><input id=kw name=wd class=s_ipt value maxlength=255 autocomplete=off autofocus=autofocus></span><span class="bg s_btn_wr"><input type=submit id=su value=百度一下 class="bg s_btn" autofocus></span> </form> </div> </div> <div id=u1> <a href=http://news.baidu.com name=tj_trnews class=mnav>新闻</a> <a href=https://www.hao123.com name=tj_trhao123 class=mnav>hao123</a> <a href=http://map.baidu.com name=tj_trmap class=mnav>地图</a> <a href=http://v.baidu.com name=tj_trvideo class=mnav>视频</a> <a href=http://tieba.baidu.com name=tj_trtieba class=mnav>贴吧</a> <noscript> <a href=http://www.baidu.com/bdorz/login.gif?login&amp;tpl=mn&amp;u=http%3A%2F%2Fwww.baidu.com%2f%3fbdorz_come%3d1 name=tj_login class=lb>登录</a> </noscript> <script>document.write('<a href="http://www.baidu.com/bdorz/login.gif?login&tpl=mn&u='+ encodeURIComponent(window.location.href+ (window.location.search === "" ? "?" : "&")+ "bdorz_come=1")+ '" name="tj_login" class="lb">登录</a>');                </script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;">更多产品</a> </div> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com>关于百度</a> <a href=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>&copy;2017&nbsp;Baidu&nbsp;<a href=http://www.baidu.com/duty/>使用百度前必读</a>&nbsp; <a href=http://jianyi.baidu.com/ class=cp-feedback>意见反馈</a>&nbsp;京ICP证030173号&nbsp; <img src=//www.baidu.com/img/gs.gif> </p> </div> </div> </div> </body> </html>

通过简单尝试，证明两点：

一是，这个还是可以使用的；
二是，原来使用如此简单。

如果要你手写一个http请求，或许你脑海里一篇空白，会去搜索各种资料。

我们再试一个复杂的

接口：

接口地址：https://erwin-api.fengwenyi.com/erwin/blog/page
请求方法：GET
参数：currentPage，pageSize
参数格式：form
响应：application/json

String url = "https://erwin-api.fengwenyi.com/erwin/bookmark/page?currentPage=1&pageSize=10";Request request = new Request();
request.setUrl(url);
request.setMethod(Request.Method.GET);Map<String, String> headerMap = new HashMap<>();
headerMap.put("Accept", "application/json");Request.Option option = new Request.Option();
option.setHeaders(headerMap);try {System.out.println(HttpUtils.execute(request, option));
} catch (IOException e) {throw new RuntimeException(e);
}

响应结果：

{"code":"SUCCESS","message":"Success","success":true,"header":null,"body":{"currentPage":1,"pageSize":10,"totalRows":661,"totalPages":67,"content":[{"id":"1634772578877935617","timestamp":1678595130000,"enabledState":null,"name":"VScode 中文显示出现黄色方框的解决方法_vscode汉字被框住_YJer的博客-CSDN博客","url":"https://blog.csdn.net/qq_33249042/article/details/123252625","icon":null,"classifyName":"软件","classifyId":"1522587269600481281"},{"id":"1632640455110922241","timestamp":1678086792000,"enabledState":null,"name":"Spring中init-method和destroy-method的四种方式_星夜孤帆的博客-CSDN博客","url":"https://blog.csdn.net/qq_38826019/article/details/117387398","icon":null,"classifyName":"Spring","classifyId":"1522586360887742466"},{"id":"1631597310596190209","timestamp":1677838087000,"enabledState":null,"name":"vue3 + elemenplus实现导航栏 - 掘金","url":"https://juejin.cn/post/7084871748608327687","icon":null,"classifyName":"前端","classifyId":"1525554881275990018"},{"id":"1631593154401636354","timestamp":1677837096000,"enabledState":null,"name":"Spring bean 创建过程源码解析 - 腾讯云开发者社区-腾讯云","url":"https://cloud.tencent.com/developer/article/1631160","icon":null,"classifyName":"Spring","classifyId":"1522586360887742466"},{"id":"1631592987673858050","timestamp":1677837056000,"enabledState":null,"name":"SpringBoot之容器启动源码分析与Bean加载_springboot加载bean 源码_minemine0418的博客-CSDN博客","url":"https://blog.csdn.net/minemine0418/article/details/102308912","icon":null,"classifyName":"Spring Boot","classifyId":"1522586446766116865"},{"id":"1631586585454678018","timestamp":1677835530000,"enabledState":null,"name":"Spring-Bean生命周期 - 知乎","url":"https://zhuanlan.zhihu.com/p/158468104","icon":null,"classifyName":"Spring","classifyId":"1522586360887742466"},{"id":"1631579732104548354","timestamp":1677833896000,"enabledState":null,"name":"一文读懂 Spring Bean 的生命周期_spring bean的生命周期_老周聊架构的博客-CSDN博客","url":"https://blog.csdn.net/riemann_/article/details/118500805","icon":null,"classifyName":"Spring","classifyId":"1522586360887742466"},{"id":"1630768897186697218","timestamp":1677640578000,"enabledState":null,"name":"MySQL同时统计多个条件的记录条数_ztnhnr的博客-CSDN博客","url":"https://blog.csdn.net/ztnhnr/article/details/107165942","icon":null,"classifyName":"MySQL","classifyId":"1522586805693681666"},{"id":"1630768792098410497","timestamp":1677640553000,"enabledState":null,"name":"sql查询近七天，近两周，近一个月的数据_sql最近一周数据_心诚则灵＇的博客-CSDN博客","url":"https://blog.csdn.net/wenchangwenliu/article/details/119891790","icon":null,"classifyName":"MySQL","classifyId":"1522586805693681666"},{"id":"1630480535938764801","timestamp":1677571827000,"enabledState":null,"name":"开源流程引擎哪个好，如何选型？ - 知乎","url":"https://zhuanlan.zhihu.com/p/369761832","icon":null,"classifyName":"Java","classifyId":"1522586296119300097"}]}
}

响应结果，还是符合预期的。

当然，HTTP还有其他，比如超时等等，下面看看完整版的请求示例：

Map<String, Object> paramMap = new HashMap<>();
paramMap.put("currentPage", 1);
paramMap.put("pageSize", 10);Map<String, String> headerMap = new HashMap<>();
headerMap.put("Accept", "application/json");Request request = new Request();
request.setUrl("https://erwin-api.fengwenyi.com/erwin/bookmark/page");
request.setParam(paramMap);
request.setMethod(Request.Method.GET);
request.setUtil(Request.Util.OkHttp);Request.Option option = new Request.Option();
option.setHeaders(headerMap);
option.setConnectTimeoutSecond(3);
option.setReadTimeoutSecond(5);
option.setLogLevel(Request.LogLevel.DEBUG);try {String result = HttpUtils.execute(request, option);System.out.println(result);
} catch (IOException e) {throw new RuntimeException(e);
}

响应结果也是跟上面一样的。

第三部分：分享HttpUtils是如何封装的

首先是 Request 和 Response 对应HTTP的请求和响应，包路径如下：

com.fengwenyi.javalib.http.Request
com.fengwenyi.javalib.http.Response

另外，com.fengwenyi.javalib.http.Request.Option 来存放HTTP参数配置。

这一部分的思路来源是 Spring Cloud OpenFeign。

为了兼容多种HTTP工具实现请求，引入了 HttpClientFactory，其他工具类，只要实现 HttpClient 接口，就行。

com.fengwenyi.javalib.http.client.HttpClient
com.fengwenyi.javalib.http.client.HttpClientFactory

欧克，下面我们就以代码来看看：

HttpUtils#execute

public static String execute(Request request, Request.Option option) throws IOException {check(request);HttpClient httpClient = HttpClientFactory.get(request.getUtil());Response response = httpClient.execute(request, option);return handleResponse(response);
}

HttpClientFactory#get

public static HttpClient get(Request.Util httpUtil) {if (Request.Util.JDK == httpUtil) {return new JdkHttpClient();} else if (Request.Util.OkHttp == httpUtil) {return new OkHttpClient();} else {throw new RuntimeException("not find http util: " + httpUtil.name());}
}

所以，只需要实现 HttpClient#execute 接口就行。

Response execute(Request request, Request.Option option) throws IOException;