RestTemplate 未传递 Origin 标头答案

【问题标题】：RestTemplate not passing Origin headerRestTemplate 未传递 Origin 标头
【发布时间】：2017-01-17 14:24:48
【问题描述】：

我正在尝试使用 Spring 的 RestTemplate 发出跨域请求。通信是在两个 Spring-boot webapps 之间完成的，它们都运行在 localhost 但不同的端口上。我要做的是：

HttpHeaders httpHeaders = new HttpHeaders();
httpHeaders.setOrigin("http://localhost:8083");
httpHeaders.add("Authorization", token);

HttpEntity<Void> httpEntity = new HttpEntity<>(httpHeaders);

ParameterizedTypeReference<List<MyObj>> beanType = new ParameterizedTypeReference<List<MyObj>>() {};
ResponseEntity<List<MyObj>> list = restTemplate.exchange(serviceURL, HttpMethod.GET, httpEntity, beanType);

调用被执行，“Authorization”标头通过就好了，但无论我尝试什么，接收端都没有“Origin”标头。当我使用其他工具（SoapUI、RestClient Chrome 插件等）创建类似请求时，标头会按照我提供的方式传递。

为了在接收端打印所有标题，我使用了 javax.servlet.Filter 的实现：

public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
        throws IOException, ServletException {
    HttpServletRequest request = (HttpServletRequest) req;
    HttpServletResponse response = (HttpServletResponse) res;
    Enumeration<String> headerNames = request.getHeaderNames();
    while (headerNames.hasMoreElements()) {
        String headerName = headerNames.nextElement();
        log.info(headerName + ": " + request.getHeader(headerName));
    }
}

为什么使用RestTemplate时没有传递origin header？

【问题讨论】：

标签： java spring spring-mvc resttemplate

【解决方案1】：

遇到了同样的问题，我花了一个世纪来解决。

根本原因是 RestTemplate 文档中的这一行

注意：默认情况下，RestTemplate 依赖于标准 JDK 工具来建立 HTTP 连接。

如果您检查 Java 中 HttpUrlConnection 类的源代码，您会发现下面的代码块，并且标头 Origin 是禁止更改的受限标头之一：

/*
 * Restrict setting of request headers through the public api
 * consistent with JavaScript XMLHttpRequest2 with a few
 * exceptions. Disallowed headers are silently ignored for
 * backwards compatibility reasons rather than throwing a
 * SecurityException. For example, some applets set the
 * Host header since old JREs did not implement HTTP 1.1.
 * Additionally, any header starting with Sec- is
 * disallowed.
 *
 * The following headers are allowed for historical reasons:
 *
 * Accept-Charset, Accept-Encoding, Cookie, Cookie2, Date,
 * Referer, TE, User-Agent, headers beginning with Proxy-.
 *
 * The following headers are allowed in a limited form:
 *
 * Connection: close
 *
 * See http://www.w3.org/TR/XMLHttpRequest2.
 */
 private static final boolean allowRestrictedHeaders;
 private static final Set<String> restrictedHeaderSet;
 private static final String[] restrictedHeaders = {
    /* Restricted by XMLHttpRequest2 */
    //"Accept-Charset",
    //"Accept-Encoding",
    "Access-Control-Request-Headers",
    "Access-Control-Request-Method",
    "Connection", /* close is allowed */
    "Content-Length",
    //"Cookie",
    //"Cookie2",
    "Content-Transfer-Encoding",
    //"Date",
    //"Expect",
    "Host",
    "Keep-Alive",
    "Origin",
    // "Referer",
    // "TE",
    "Trailer",
    "Transfer-Encoding",
    "Upgrade",
    //"User-Agent",
    "Via"
};

这个问题有一个简单的解决方法，只需要设置一个JVM参数

-Dsun.net.http.allowRestrictedHeaders=true

或在代码中添加一行

System.setProperty("sun.net.http.allowRestrictedHeaders", "true");

抑制限制。

【讨论】：

【解决方案2】：

有同样的问题。我发现 apache http 客户端没有这个问题，并使用 'Origin' 发送请求：http://hc.apache.org/

HttpOptions httpOptions = new 
HttpOptions(url)
httpOptions.setHeader("Origin", "test")
httpOptions.setHeader("Content-Type", "application/json")
BasicHttpClientConnectionManager manager = new 
BasicHttpClientConnectionManager()
HttpClient client = new MinimalHttpClient(manager)
client.execute(httpOptions)

【讨论】：