最近在做一个转发功能，zuul + ribbon + resttemplate 进行路由、负载、转发的功能
基本准备就绪，在微信自动登陆那遇到了一个坑，ribbon 系统用resttemplate 转发A系统的资源，在微信自动登陆的地方，A系统重定向到微信的地址，类似下面的代码
redirect:
https://open.weixin.qq.com/connect/oauth2/authorize?appid=wx3290f3d5****&redirect_uri=http://***.com/weixin/wxAuthRedirect?redirectUrl=http%3A%2F%2F192.168.10.116%3A8081%2Finternal%2Fpage%2Fuser%2Flogin_wx&response_type=code&scope=snsapi_userinfo&state=state#wechat_redirect
结果resttemplate 自动重定向到本地的地址，如下所示：
http://192.168.10.116:**/connect/oauth2/authorize**
仔细思考了下，大概就是resttemplate 的重定向问题，查了查资料，找到一个类HttpComponentsClientHttpRequestFactory，RestTemplate初始化提供了这个类的参数
/**
* Create a new instance of the {@link RestTemplate} based on the given {@link ClientHttpRequestFactory}.
* @param requestFactory HTTP request factory to use
* @see org.springframework.http.client.SimpleClientHttpRequestFactory
* @see org.springframework.http.client.HttpComponentsClientHttpRequestFactory
*/
public RestTemplate(ClientHttpRequestFactory requestFactory) {
this();
setRequestFactory(requestFactory);
}
HttpComponentsClientHttpRequestFactory继承自ClientHttpRequestFactory，这个类的子类有HttpComponentsClientHttpRequestFactory和SimpleClientHttpRequestFactory
找到SimpleClientHttpRequestFactory，有如下方法：
第一种方式：
/**
* Template method for preparing the given {@link HttpURLConnection}.
* <p>The default implementation prepares the connection for input and output, and sets the HTTP method.
* @param connection the connection to prepare
* @param httpMethod the HTTP request method ({@code GET}, {@code POST}, etc.)
* @throws IOException in case of I/O errors
*/
protected void prepareConnection(HttpURLConnection connection, String httpMethod) throws IOException {
if (this.connectTimeout >= 0) {
connection.setConnectTimeout(this.connectTimeout);
}
if (this.readTimeout >= 0) {
connection.setReadTimeout(this.readTimeout);
} connection.setDoInput(true); if ("GET".equals(httpMethod)) {
connection.setInstanceFollowRedirects(true);
}
else {
connection.setInstanceFollowRedirects(false);
} if ("POST".equals(httpMethod) || "PUT".equals(httpMethod) ||
"PATCH".equals(httpMethod) || "DELETE".equals(httpMethod)) {
connection.setDoOutput(true);
}
else {
connection.setDoOutput(false);
} connection.setRequestMethod(httpMethod);
}
可以看到setInstanceFollowRedirects，get请求是可以重定向的，其他方法禁止了重定向，于是建个SimpleClientHttpRequestFactory的子类，禁用重定向。
于是乎 NoRedirectClientHttpRequestFactory.java
import java.io.IOException;
import java.net.HttpURLConnection; import org.springframework.http.client.SimpleClientHttpRequestFactory; public class NoRedirectClientHttpRequestFactory extends SimpleClientHttpRequestFactory { @Override
protected void prepareConnection(HttpURLConnection connection, String httpMethod) throws IOException {
// TODO Auto-generated method stub
super.prepareConnection(connection, httpMethod);
// 禁止自动重定向
connection.setFollowRedirects(false);
}
}
NoRedirectClientHttpRequestFactory httpRequestFactory = new NoRedirectClientHttpRequestFactory();
RestTemplate restTemplate = new RestTemplate(httpRequestFactory);
接着，似乎更换ClientHttpRequestFactory并不合心意，还是要使用HttpComponentsClientHttpRequestFactory来实现，HttpComponentsClientHttpRequestFactory是可以自定义HttpClient的，于是查到了HttpClient头上，HttpClient是可以设置Redirect的，
第二种方式：
HttpClient httpClient = HttpClientBuilder.create()
.setRedirectStrategy(new LaxRedirectStrategy())
.build();
httpRequestFactory.setHttpClient(httpClient);
RestTemplate restTemplate = new RestTemplate(httpRequestFactory);
默认提供了两个类，DefaultRedirectStrategy和LaxRedirectStrategy，LaxRedirectStrategy继承自DefaultRedirectStrategy
DefaultRedirectStrategy.java
/**
* Redirectable methods.
*/
private static final String[] REDIRECT_METHODS = new String[] {
HttpGet.METHOD_NAME,
HttpHead.METHOD_NAME
};
LaxRedirectStrategy.java
/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/ package org.apache.http.impl.client; import org.apache.http.annotation.Contract;
import org.apache.http.annotation.ThreadingBehavior;
import org.apache.http.client.methods.HttpDelete;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpHead;
import org.apache.http.client.methods.HttpPost; /**
* Lax {@link org.apache.http.client.RedirectStrategy} implementation
* that automatically redirects all HEAD, GET, POST, and DELETE requests.
* This strategy relaxes restrictions on automatic redirection of
* POST methods imposed by the HTTP specification.
*
* @since 4.2
*/
@Contract(threading = ThreadingBehavior.IMMUTABLE)
public class LaxRedirectStrategy extends DefaultRedirectStrategy { public static final LaxRedirectStrategy INSTANCE = new LaxRedirectStrategy(); /**
* Redirectable methods.
*/
private static final String[] REDIRECT_METHODS = new String[] {
HttpGet.METHOD_NAME,
HttpPost.METHOD_NAME,
HttpHead.METHOD_NAME,
HttpDelete.METHOD_NAME
}; @Override
protected boolean isRedirectable(final String method) {
for (final String m: REDIRECT_METHODS) {
if (m.equalsIgnoreCase(method)) {
return true;
}
}
return false;
} }
这就很清晰了，copy一份LaxRedirectStrategy的代码，改写掉REDIRECT_METHODS中的定义方法，如下：
import org.apache.http.annotation.Contract;
import org.apache.http.annotation.ThreadingBehavior;
import org.apache.http.impl.client.DefaultRedirectStrategy; /**
*
* @ClassName: MyRedirectStrategy
* @Description: TODO
* @author thinklight
* @date 2018年4月20日 下午2:47:29
*
*/
@Contract(threading = ThreadingBehavior.IMMUTABLE)
public class MyRedirectStrategy extends DefaultRedirectStrategy { public static final MyRedirectStrategy INSTANCE = new MyRedirectStrategy(); /**
* Redirectable methods.
*/
private static final String[] REDIRECT_METHODS = new String[] {}; @Override
protected boolean isRedirectable(final String method) {
for (final String m: REDIRECT_METHODS) {
if (m.equalsIgnoreCase(method)) {
return true;
}
}
return false;
}
}
ribbon+微信各种重定向问题，解决了。
第三种方式：
自己蠢了，今天因为cookie的问题发现了简单的方式
HttpClient httpClient = HttpClientBuilder.create().disableCookieManagement().disableRedirectHandling().build();
完整代码如下：
@Autowired
RestTemplate restTemplate; @Bean
@LoadBalanced
RestTemplate restTemplate() {
HttpComponentsClientHttpRequestFactory httpRequestFactory = new HttpComponentsClientHttpRequestFactory();
// NoRedirectClientHttpRequestFactory httpRequestFactory = new NoRedirectClientHttpRequestFactory();// 此类型不能使用httpClient
httpRequestFactory.setConnectionRequestTimeout(2000);
httpRequestFactory.setConnectTimeout(10000);
httpRequestFactory.setReadTimeout(7200000);
// HttpClient httpClient = HttpClientBuilder.create()
// .setRedirectStrategy(new MyRedirectStrategy())
// .build();
HttpClient httpClient = HttpClientBuilder.create().disableCookieManagement().disableRedirectHandling().build();
httpRequestFactory.setHttpClient(httpClient);
RestTemplate restTemplate = new RestTemplate(httpRequestFactory);
logger.debug("指定字符编码为UTF-8,原编码为ISO-8859-1");
restTemplate.getMessageConverters().set(1, new StringHttpMessageConverter(StandardCharsets.UTF_8));
logger.debug("RestTemple默认能转换为application/json，转换追加text/plain类型");
restTemplate.getMessageConverters().add(new WxMappingJackson2HttpMessageConverter());
return restTemplate;
}
重定向参考：https://www.dozer.cc/2014/05/disable-resttemplate-redirect.html
cookie参考：https://*.com/questions/10175649/resttemplate-and-cookie
https://*.com/questions/22853321/resttemplate-client-with-cookies