jdk8使用okhttp发送http2请求

本文主要用于工作记录，在项目中遇到了就记录一下

在早期，原生的JDK8是不支持HTTP/2协议的，所以，要想使用这个特性，需要有web服务器和应用环境的支持，
例如：在VM中增加-Xbootclasspath/p:/Users/a1234/Downloads/alpn-boot-8.1.11.v20170118.jar来配合使用

但是从8u252开始，ALPN层已经从Java 11向后移植到了Java 8。意味着，只要使用Java
8u252或更新版本，不再要求使用Conscrypt和Jetty就可以使用HTTP/2了。

重点来了：一定要先检查自己的jdk版本是否大于8u252，然后就可以在项目中集成okhttp

项目pom配置

<!-- SpringBoot 依赖配置 -->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-dependencies</artifactId><version>2.7.2</version><type>pom</type><scope>import</scope>
</dependency><!-- okhttp 依赖配置 -->
<dependency><groupId>com.squareup.okhttp3</groupId><artifactId>okhttp</artifactId><version>4.9.3</version>
</dependency>

简单封装获取http2client请求

 	/*** 获取httpClient请求** @param maxTotalConnections             最大连接数* @param connectionKeepAliveTimeInMillis 最长连接保持活动时间* @return*/private static OkHttpClient createHttpClient(int maxTotalConnections, long connectionKeepAliveTimeInMillis) {ConnectionPool connectionPool = new ConnectionPool(maxTotalConnections, connectionKeepAliveTimeInMillis, TimeUnit.MILLISECONDS);return new OkHttpClient.Builder().followRedirects(false)
//                .protocols(Collections.singletonList(Protocol.H2_PRIOR_KNOWLEDGE)).retryOnConnectionFailure(true).connectionPool(connectionPool).build();}

GET请求示例

	/*** GET请求示例** @return* @throws IOException*/private String getTokenResStr() throws IOException {Request request = new Request.Builder().addHeader("Nonce", “123”).addHeader("Authorization", configData.getAuthorizationCode()).url(“url地址”).build();//GET by defaultOkHttpClient httpClient = createHttpClient(100, 30000);Response response = httpClient.newCall(request).execute();if (!response.isSuccessful()) {throw new IOException("Unexpected code " + response);}return response.body().string();}

POST请求示例

	/*** POST请求示例** @param orderId* @param tokenResStr* @return* @throws IOException*/private String getOrderDetail(String orderId, String tokenResStr) throws IOException {JSONObject tokenRes = JSONObject.parseObject(tokenResStr);// tokenString accessToken = tokenRes.getString("access_token");// token类型String tokenType = tokenRes.getString("token_type");String authorizationStr = firstUpperCase(tokenType) + " " + accessToken;Request request = new Request.Builder().addHeader("Authorization", authorizationStr).addHeader("Content-Type", "application/json").url(configData.getDetailRpcUrl() + orderId).build();OkHttpClient httpClient = createHttpClient(100, 30000);Response response = httpClient.newCall(request).execute();if (!response.isSuccessful()) {throw new IOException("Unexpected code " + response);}return response.body().string();