HTTP 示例

本节通过几个示例总结 Spring Integration 的 HTTP 支持内容。

Multipart HTTP 请求 — RestTemplate (客户端) 与 Http 入站网关 (服务器)

此示例展示了使用 Spring 的 RestTemplate 发送 multipart HTTP 请求并使用 Spring Integration HTTP 入站适配器接收它是多么简单。我们创建一个 MultiValueMap 并用 multipart 数据填充它。RestTemplate 会负责其余部分（双关语，非故意）通过将其转换为 MultipartHttpServletRequest。这个特定的客户端发送一个 multipart HTTP 请求，其中包含公司名称和一个图片文件（公司 logo）。以下清单展示了这个示例

RestTemplate template = new RestTemplate();
String uri = "http://localhost:8080/multipart-http/inboundAdapter.htm";
Resource s2logo =
   new ClassPathResource("org/springframework/samples/multipart/spring09_logo.png");
MultiValueMap map = new LinkedMultiValueMap();
map.add("company", "SpringSource");
map.add("company-logo", s2logo);
HttpHeaders headers = new HttpHeaders();
headers.setContentType(new MediaType("multipart", "form-data"));
HttpEntity request = new HttpEntity(map, headers);
ResponseEntity<?> httpResponse = template.exchange(uri, HttpMethod.POST, request, null);

这就是客户端所需的全部。

在服务器端，我们有以下配置

<int-http:inbound-channel-adapter id="httpInboundAdapter"
    channel="receiveChannel"
    path="/inboundAdapter.htm"
    supported-methods="GET, POST"/>

<int:channel id="receiveChannel"/>

<int:service-activator input-channel="receiveChannel">
    <bean class="org.springframework.integration.samples.multipart.MultipartReceiver"/>
</int:service-activator>

<bean id="multipartResolver"
    class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>

'httpInboundAdapter' 接收请求并将其转换为一个 payload 是 LinkedMultiValueMap 的 Message。然后我们在 'multipartReceiver' service-activator 中解析它，如下例所示

public void receive(LinkedMultiValueMap<String, Object> multipartRequest){
    System.out.println("### Successfully received multipart request ###");
    for (String elementName : multipartRequest.keySet()) {
        if (elementName.equals("company")){
            System.out.println("\t" + elementName + " - " +
                ((String[]) multipartRequest.getFirst("company"))[0]);
        }
        else if (elementName.equals("company-logo")){
            System.out.println("\t" + elementName + " - as UploadedMultipartFile: " +
                ((UploadedMultipartFile) multipartRequest
                    .getFirst("company-logo")).getOriginalFilename());
        }
    }
}

您应该会看到以下输出

### Successfully received multipart request ###
   company - SpringSource
   company-logo - as UploadedMultipartFile: spring09_logo.png