通过forward跳转到perview页面时，加一个时间戳

src/main/java/com/uas/report/controller/PrintController.java

@@ -6,6 +6,7 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.net.URLEncoder;
 import java.sql.SQLException;
+import java.util.Date;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -44,6 +45,8 @@ import net.sf.jasperreports.engine.JRException;
 @RequestMapping("/print")
 public class PrintController {
 
+	private static final long timestamp = new Date().getTime();
+
 	@Autowired
 	private PrintService printService;
 
@@ -92,7 +95,7 @@ public class PrintController {
 		// 预览或打印
 		if (printType.equals(ReportConstants.PRINT_TYPE_PREVIEW)
 				|| printType.equals(ReportConstants.PRINT_TYPE_PRINT)) {
-			request.getRequestDispatcher("preview").forward(request, response);
+			request.getRequestDispatcher("preview?t=" + timestamp).forward(request, response);
 		}
 		// 下载pdf、纯数据excel
 		else if (printType.equals(ReportConstants.PRINT_TYPE_PDF)) {