java - 使用 Apache Wink 通过 Java REST 服务返回 excel 文档

Question

我需要从 Java REST 服务返回一个 Microsoft Excel 文件。我正在使用 WebSphere 8.5，它本质上使用 Apache Wink 作为 JAX-RS 实现；这是我无法更改的要求。我也在使用 Java 7 JDK。这是我收到的错误:

org.apache.wink.server.internal.handlers.FlushResultHandler handleResponse The system could not find a javax.ws.rs.ext.MessageBodyWriter or a DataSourceProvider class for the com.somewhere.else.message.core.BaseResponseMessage type and application/vnd.ms-excel mediaType. Ensure that a javax.ws.rs.ext.MessageBodyWriter exists in the JAX-RS application for the type and media type specified.

这是我的 Java Resource 类方法:

@GET
@Path("/report")
@Produces("application/vnd.ms-excel")
public Response getReport() { 

    int fileSize = 0;

    byte[] reportByteArray = null;

    ResponseBuilder responseBuilder = null;
    InputStream report = null;

    BaseResponseMessage<InputStream> baseResponseMessage = new  
    BaseResponseMessage<InputStream>();

    Path reportPath = null;

    String localPath = "C:/Users/me/Report.xls";

    responseBuilder = Response.ok(baseResponseMessage); 

    responseBuilder.header("Content-Description", "File Transfer");
    responseBuilder.header("Content-Disposition", "attachment; 
         filename=Report.xls");
    responseBuilder.header("Content-Transfer-Encoding", "binary");
    responseBuilder.header("Connection", "Keep-Alive");

    reportPath = Paths.get(localPath);

    if (Files.exists(reportPath)) {

        if (Files.isReadable(reportPath)) {

            reportByteArray = Files.readAllBytes(reportPath);

            report = new ByteArrayInputStream(reportByteArray);
        }
    }

    fileSize = report.available();

    responseBuilder.header("Content-Length", fileSize);

    baseResponseMessage.setPayload(report);

    return responseBuilder.build();
}

通过查看调试器，我确实知道路径和 excel 文件已正确找到，并且 fileSize 也已正确填充。

我很乐意提供所需的任何更多信息。感谢您的宝贵时间!

Answer 1

我认为问题出在 @Produces 注释上。默认情况下，JAX-RS 可能不知道如何处理 "application/vnd.ms-excel"。您可以尝试使用

@Produces( MediaType.APPLICATION_OCTET_STREAM)

这是示例代码，

1. 创建一个 JEE 6 网络项目

2. 创建了一个应用程序类

   import javax.ws.rs.ApplicationPath;  
   import javax.ws.rs.core.Application; 
   
   @ApplicationPath("/services/*")  
   public class MyApplication extends Application {  
   
   }  
   

3. 创建了一个 REST 资源类，

   import java.io.File;  
   import javax.ws.rs.GET;  
   import javax.ws.rs.Path;  
   import javax.ws.rs.Produces;  
   import javax.ws.rs.core.MediaType;  
   import javax.ws.rs.core.Response;  
   import javax.ws.rs.core.Response.ResponseBuilder;  
   
   
   @Path("/hello")  
   public class HelloResource {  
   
       @GET  
       @Path("excel")  
       @Produces(MediaType.APPLICATION_OCTET_STREAM)  
       public Response test2() {  
           File file = new File("C:/users/arun/rest-test.xlsx");  
           ResponseBuilder rb = Response.ok(file);  
           rb.header("content-disposition", "attachment; filename=rest-test.xlsx");  
           return rb.build();  
       }  
   }