一、RestTemplate 简介
Spring RestTemplate是Spring提供的用于访问Rest服务的客户端，RestTemplate 提供了多种便捷访问远程Http服务的方法，能够大大提高客户端的编写效率.
RestTemplate包含以下几个部分：
- HttpMessageConverter 对象转换器:将请求对象转换为具体的数据格式输出，例
入:Jaxb2RootElementHttpMessageConverterket提供对xml格式的输入输出支持 - ClientHttpRequestFactory HTTP请求工厂，默认是JDK的HttpURLConnection，
可以通过使用ClientHttpRequestFactory指定不同的HTTP请求方式 - ResponseErrorHandler 异常错误处理
- ClientHttpRequestInterceptor 请求拦截器
RestTemplate通过HttpEntity添加消息headers
二、springboot 通过RestTemplate实现https访问
import java.io.InputStream; import java.security.KeyStore; import java.util.ArrayList; import java.util.Collections; import java.util.List; import javax.net.ssl.HostnameVerifier; import javax.net.ssl.HttpsURLConnection; import javax.net.ssl.KeyManagerFactory; import javax.net.ssl.SSLContext; import javax.net.ssl.SSLSession; import javax.net.ssl.TrustManager; import org.apache.commons.lang3.StringUtils; import org.apache.http.HttpHost; import org.apache.http.conn.ssl.SSLConnectionSocketFactory; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.impl.client.HttpClients; import org.apache.http.ssl.SSLContexts; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Conditional; import org.springframework.context.annotation.Configuration; import org.springframework.http.MediaType; import org.springframework.http.client.HttpComponentsClientHttpRequestFactory; import org.springframework.http.converter.json.GsonHttpMessageConverter; import org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter; import org.springframework.web.client.RestTemplate; /** * service相关配置 * * @date 2017年3月1日 * @since 1.0.0 */ @Configuration public class ServiceConfigConfiguration { @Autowired sslProperties sslProperties ; /** * 访问SSL的Template * * @throws Exception */ @Bean("sslRestTemplate") @Conditional(sslCondition.class) public RestTemplate tmsRestTemplate() throws Exception { //新建RestTemplate对象 RestTemplate restTemplate = new RestTemplate(); //判断证书文件地址是否存在 if (StringUtils.isNotEmpty(sslProperties.getKeyfile())) { //在握手期间，如果URL的主机名和服务器的标识主机名不匹配，则验证机制可以回调此接口的实现 程序来确定是否应该允许此连接 HostnameVerifier hv = new HostnameVerifier() { @Override public boolean verify(String urlHostName, SSLSession session) { return true; } }; HttpsURLConnection.setDefaultHostnameVerifier(hv); //构建SSL-Socket链接工厂 SSLConnectionSocketFactory ssLSocketFactory = buildSSLSocketFactory("PKCS12", sslProperties.getKeyfile(),sslProperties.getPassword(), Lists.newArrayList("TLSv1"), true); //Spring提供HttpComponentsClientHttpRequestFactory指定使用HttpClient作为底层实现创建 HTTP请求 HttpComponentsClientHttpRequestFactory httpRequestFactory = new HttpComponentsClientHttpRequestFactory( HttpClients.custom().setSSLSocketFactory(ssLSocketFactory).build() ); //设置传递数据超时时长 httpRequestFactory.setReadTimeout(sslProperties.getTimeout()); //设置建立连接超时时长 httpRequestFactory.setConnectTimeout(sslProperties.getTimeout()); //设置获取连接超时时长 httpRequestFactory.setConnectionRequestTimeout(tmsProperties.getTimeout()); restTemplate.setRequestFactory(httpRequestFactory); // 返回消息头也是text_html,消息格式是XML,添加新的message converter Jaxb2RootElementHttpMessageConverter messageConverter = new Jaxb2RootElementHttpMessageConverter(); //设置message Converter支持的媒体类型 List<MediaType> finalMediaTypes = new ArrayList<>(); finalMediaTypes.addAll(messageConverter.getSupportedMediaTypes()); finalMediaTypes.add(MediaType.TEXT_HTML); messageConverter.setSupportedMediaTypes(finalMediaTypes); restTemplate.setMessageConverters(Lists.newArrayList(messageConverter)); } return restTemplate; } /** * 构建SSLSocketFactory * * @param keyStoreType * @param keyFilePath * @param keyPassword * @param sslProtocols * @param auth 是否需要client默认相信不安全证书 * @return * @throws Exception */ private SSLConnectionSocketFactory buildSSLSocketFactory(String keyStoreType, String keyFilePath, String keyPassword, List<String> sslProtocols, boolean auth) throws Exception { //证书管理器，指定证书及证书类型 KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm()); //KeyStore用于存放证书，创建对象时 指定交换数字证书的加密标准 KeyStore keyStore = KeyStore.getInstance(keyStoreType); InputStream inputStream = resourcePatternResolver.getResource(keyFilePath).getInputStream(); try { //添加证书 keyStore.load(inputStream, keyPassword.toCharArray()); } finally { inputStream.close(); } keyManagerFactory.init(keyStore, keyPassword.toCharArray()); SSLContext sslContext = SSLContext.getInstance("SSL"); if (auth) { // 设置信任证书（绕过TrustStore验证） TrustManager[] trustAllCerts = new TrustManager[1]; TrustManager trustManager = new AuthX509TrustManager(); trustAllCerts[0] = trustManager; sslContext.init(keyManagerFactory.getKeyManagers(), trustAllCerts, null); HttpsURLConnection.setDefaultSSLSocketFactory(sslContext.getSocketFactory()); } else { //加载证书材料，构建sslContext sslContext = SSLContexts.custom().loadKeyMaterial(keyStore, keyPassword.toCharArray()).build(); } SSLConnectionSocketFactory sslConnectionSocketFactory = new SSLConnectionSocketFactory(sslContext, sslProtocols.toArray(new String[sslProtocols.size()]), null, new HostnameVerifier() { // 这里不校验hostname @Override public boolean verify(String urlHostName, SSLSession session) { return true; } }); return sslConnectionSocketFactory; } }AuthX509TrustManager 证书信任管理器类就是实现了接口X509TrustManager的类。可以自己实现该接口，信任我们指定的证书
public class AuthX509TrustManager implements javax.net.ssl.TrustManager, javax.net.ssl.X509TrustManager { public java.security.cert.X509Certificate[] getAcceptedIssuers() { return null; } public void checkServerTrusted(java.security.cert.X509Certificate[] certs, String authType) throws java.security.cert.CertificateException { return; } public void checkClientTrusted(java.security.cert.X509Certificate[] certs, String authType) throws java.security.cert.CertificateException { return; } }