配置资源以通过 JAX-RS 2.0 中的 HTML 表单提交接收 multipart/form-data 部分

传输文件数据的 HTML 表单必须使用 POST 方法和“multipart/form-data”操作进行配置。JAX-RS 资源方法可通过两种方式的其中之一接收此数据,此方法使用 IBM Java™ API for RESTful Web Services (JAX-RS) 实现接受此数据。

关于此任务

此任务提供有关配置 JAX-RS 方法以使用和产生 multipart/form-data 的指示信息。以下示例演示 HTML 表单:
<form action="http://www.example.com/" method="POST" enctype="multipart/form-data">
    <input type="text" name="fileid" />
    <br />
    <input type="text" name="description" />
    <br />
    <input type="file" name="thefile" />
    <br />
    <input type="submit" name="submit" value="submit"/>
</form>
可实现 IBM JAX-RS 以接收部件中的数据,所以必要时您可自己处理这些部件。

过程

创建资源方法。 必须声明下列其中一个资源方法以从 HTTP POST 接收和回应 multipart/form-data 内容:
package com.example.jaxrs;
@POST
@Consumes("multipart/form-data")
@Produces("multipart/form-data")

public Response postFormData(IMultipartBody multipartBody) {
  List <IAttachment> attachments = multipartBody.getAllAttachments();
         String formElementValue = null; 
         InputStream stream = null;
         for (Iterator<IAttachment> it = attachments.iterator(); it.hasNext();) {
              IAttachment attachment = it.next();
              if (attachment == null) {
                  continue;
              }
              DataHandler dataHandler = attachment.getDataHandler();
              stream = dataHandler.getInputStream();
              MultivaluedMap<String, String> map = attachment.getHeaders();
              String fileName = null;
              String formElementName = null;
              String[] contentDisposition = map.getFirst("Content-Disposition").split(";");
              for (String tempName : contentDisposition) {
                  String[] names = tempName.split("=");
                  formElementName = names[1].trim().replaceAll("\"", "");
                  if ((tempName.trim().startsWith("filename"))) {
                      fileName = formElementName;
                  }
              }
              if (fileName == null) {
                  StringBuffer sb = new StringBuffer();
                  BufferedReader br = new BufferedReader(new InputStreamReader(stream));
                  String line = null;
                  try {
                      while ((line = br.readLine()) != null) {
                          sb.append(line);
                      }
                  } catch (IOException e) {
                      e.printStackTrace();
                  } finally {
                      if (br != null) {
                          try {
                              br.close();
                          } catch (IOException e) {
                              e.printStackTrace();
                          }
                      }
                  }
                  formElementValue = sb.toString();
                  System.out.println(formElementName + ":" + formElementValue);
                      } else {
               //handle the file as you want
               File tempFile = new File(fileName);
               ...
              }
         }
         if (stream != null) {
             stream.close();
         }
         return Response.ok("test").build();
}
package com.example.jaxrs;
@POST
@Consumes("multipart/form-data")
@Produces("multipart/form-data")

public Response postFormData(List<IAttachment>attachments) {
  List <IAttachment> attachments = multipartBody.getAllAttachments();
         String formElementValue = null; 
         InputStream stream = null;
         for (Iterator<IAttachment> it = attachments.iterator(); it.hasNext();) {
              IAttachment attachment = it.next();
              if (attachment == null) {
                  continue;
              }
              DataHandler dataHandler = attachment.getDataHandler();
              stream = dataHandler.getInputStream();
              MultivaluedMap<String, String> map = attachment.getHeaders();
              String fileName = null;
              String formElementName = null;
              String[] contentDisposition = map.getFirst("Content-Disposition").split(";");
              for (String tempName : contentDisposition) {
                  String[] names = tempName.split("=");
                  formElementName = names[1].trim().replaceAll("\"", "");
                  if ((tempName.trim().startsWith("filename"))) {
                      fileName = formElementName;
                  }
              }
              if (fileName == null) {
                  StringBuffer sb = new StringBuffer();
                  BufferedReader br = new BufferedReader(new InputStreamReader(stream));
                  String line = null;
                  try {
                      while ((line = br.readLine()) != null) {
                          sb.append(line);
                      }
                  } catch (IOException e) {
                      e.printStackTrace();
                  } finally {
                      if (br != null) {
                          try {
                              br.close();
                          } catch (IOException e) {
                              e.printStackTrace();
                          }
                      }
                  }
                  formElementValue = sb.toString();
                  System.out.println(formElementName + ":" + formElementValue);
                      } else {
               //handle the file as you want
               File tempFile = new File(fileName);
               ...
              }
         }
         if (stream != null) {
             stream.close();
         }
         return Response.ok("test").build();
}
表单 POST 提交的发起方可对 multipart 消息的一个或多个部件生成 Content-Transfer-Encoding 头。如果头为 base64quoted-printable 编码类型,那么 IBM JAX-RS 实现尝试根据此头对部件的有效内容进行自动解码。

结果

通过允许 IBM JAX-RS 实现拆分部件及对其自动解码,并通过接收仍处于编码状态的部件以便自己处理,您从 Content-Type 为 multipart/form-data 的 HTTP POST 接收并回应数据。


用于指示主题类型的图标 任务主题

文件名:twlp_jaxrs_multipart_formdata_from_html.html