如何在JAX-RS中設置響應頭，以便用戶可以看到Excel的下載彈出窗口？

Question

我編寫了使用REST JAX-RS生成Excel文件的代碼，並且確認生成的Excel文件位於GlassFish服務器目錄中。

但我的目標是當用戶點擊按鈕（生成Excel .xls）時，我想要下載彈出窗口來顯示詢問用戶是否要保存或打開.xls文件，就像任何其他Web服務一樣，文件類型。

根據我的搜索中，步驟是：

1. 生成的Excel的.xls（DONE）

2. 寫Excel以流

3. 在JAX-RS文件

   ，設定響應標題類似，

   String fileName =「Blah_Report.xls」; response.setHeader（「Content-Disposition」，「attachment; filename =」+ fileName）;

我的問題是我在JAX-RS文件中做了所有這些，而我沒有HttpServletResponse對象可用。

據 Add Response Header to JAX-RS Webservice

回答他說：

你可以在你的web服務 注入通過 @Context註釋的參考 HttpServletResponse的實際使用和的addHeader（）等。添加您的 標題。

我真的不能弄清楚到底是什麼意思，而不樣本代碼..

Answer 1

您不需要HttpServletResponse來設置響應頭。您可以使用 javax.ws.rs.core.Response。只是讓你的方法，而不是返回實體的響應：

return Response.ok(entity).header("Content-Disposition", "attachment; filename=" + fileName).build() 

如果你仍然想使用HttpServletResponse的，你可以得到它要麼注入類的領域之一，或使用性質，或者方法參數：

@Path("/resource") 
class MyResource { 

    // one way to get HttpServletResponse 
    @Context 
    private HttpServletResponse anotherServletResponse; 

    // another way 
    Response myMethod(@Context HttpServletResponse servletResponse) { 
     // ... code 
    } 
} 

Answer 2

我想通設置HTTP響應頭和流通過在標準的servlet瀏覽器顯示下載彈出。注意：我正在使用Excella，excel輸出API。

package local.test.servlet; 

import java.io.IOException; 
import java.net.URL; 
import java.net.URLDecoder; 
import javax.servlet.ServletException; 
import javax.servlet.annotation.WebServlet; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
import local.test.jaxrs.ExcellaTestResource; 
import org.apache.poi.ss.usermodel.Workbook; 
import org.bbreak.excella.core.BookData; 
import org.bbreak.excella.core.exception.ExportException; 
import org.bbreak.excella.reports.exporter.ExcelExporter; 
import org.bbreak.excella.reports.exporter.ReportBookExporter; 
import org.bbreak.excella.reports.model.ConvertConfiguration; 
import org.bbreak.excella.reports.model.ReportBook; 
import org.bbreak.excella.reports.model.ReportSheet; 
import org.bbreak.excella.reports.processor.ReportProcessor; 

@WebServlet(name="ExcelServlet", urlPatterns={"/ExcelServlet"}) 
public class ExcelServlet extends HttpServlet { 

    @Override 
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 


     try { 

      URL templateFileUrl = ExcellaTestResource.class.getResource("myTemplate.xls"); 
      // /C:/Users/m-hugohugo/Documents/NetBeansProjects/KogaAlpha/build/web/WEB-INF/classes/local/test/jaxrs/myTemplate.xls 
      System.out.println(templateFileUrl.getPath()); 
      String templateFilePath = URLDecoder.decode(templateFileUrl.getPath(), "UTF-8"); 
      String outputFileDir = "MasatoExcelHorizontalOutput"; 

      ReportProcessor reportProcessor = new ReportProcessor(); 
      ReportBook outputBook = new ReportBook(templateFilePath, outputFileDir, ExcelExporter.FORMAT_TYPE); 

      ReportSheet outputSheet = new ReportSheet("MySheet"); 
      outputBook.addReportSheet(outputSheet); 

      reportProcessor.addReportBookExporter(new OutputStreamExporter(response)); 
      System.out.println("wtf???"); 
      reportProcessor.process(outputBook); 


      System.out.println("done!!"); 
     } 
     catch(Exception e) { 
      System.out.println(e); 
     } 

    } //end doGet() 

    @Override 
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 

    } 

}//end class 



class OutputStreamExporter extends ReportBookExporter { 

    private HttpServletResponse response; 

    public OutputStreamExporter(HttpServletResponse response) { 
     this.response = response; 
    } 

    @Override 
    public String getExtention() { 
     return null; 
    } 

    @Override 
    public String getFormatType() { 
     return ExcelExporter.FORMAT_TYPE; 
    } 

    @Override 
    public void output(Workbook book, BookData bookdata, ConvertConfiguration configuration) throws ExportException { 

     System.out.println(book.getFirstVisibleTab()); 
     System.out.println(book.getSheetName(0)); 

     //TODO write to stream 
     try { 
      response.setContentType("application/vnd.ms-excel"); 
      response.setHeader("Content-Disposition", "attachment; filename=masatoExample.xls"); 
      book.write(response.getOutputStream()); 
      response.getOutputStream().close(); 
      System.out.println("booya!!"); 
     } 
     catch(Exception e) { 
      System.out.println(e); 
     } 
    } 
}//end class 

Answer 3

@Context ServletContext ctx; 
@Context private HttpServletResponse response; 

@GET 
@Produces(MediaType.APPLICATION_OCTET_STREAM) 
@Path("/download/{filename}") 
public StreamingOutput download(@PathParam("filename") String fileName) throws Exception { 
    final File file = new File(ctx.getInitParameter("file_save_directory") + "/", fileName); 
    response.setHeader("Content-Length", String.valueOf(file.length())); 
    response.setHeader("Content-Disposition", "attachment; filename=\""+ file.getName() + "\""); 
    return new StreamingOutput() { 
     @Override 
     public void write(OutputStream output) throws IOException, 
       WebApplicationException { 
      Utils.writeBuffer(new BufferedInputStream(new FileInputStream(file)), new BufferedOutputStream(output)); 
     } 
    }; 
}