HTTP 範例

本節總結我們對 Spring Integration HTTP 支援的涵蓋範圍，並提供一些範例。

Multipart HTTP 請求 — RestTemplate (用戶端) 和 Http Inbound Gateway (伺服器)

此範例示範使用 Spring 的 RestTemplate 發送 multipart HTTP 請求，並使用 Spring Integration HTTP inbound adapter 接收它有多麼簡單。我們建立一個 MultiValueMap 並用 multipart 資料填充它。RestTemplate 負責其餘部分（沒有雙關語），將其轉換為 MultipartHttpServletRequest。此特定用戶端發送一個 multipart HTTP Request，其中包含公司名稱和影像檔（公司標誌）。以下清單顯示了範例

RestTemplate template = new RestTemplate();
String uri = "https://127.0.0.1:8080/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);

這就是用戶端所需的一切。

在伺服器端，我們有以下設定

<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' 接收請求並將其轉換為 Message，其 payload 是 LinkedMultiValueMap。然後我們在 'multipartReceiver' service-activator 中解析它，如下列範例所示

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());
        }
    }
}

您應該看到以下輸出

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