-1

我请求 urlhttp://localhost:8080/myApp/reg/show?pageNumber=1&pageRange=-1 并且在show.jsp我有

<ts:pagination allData="${tecBacking.tec}"  
          pageRange="${param.pageRange}"
          pageNumber="${param.pageNumber}"
          url="show">
     <jsp:attribute name="tableHeaders">
          <th>Идентификатор</th>
          <th>Код</th>
          <th>Описание</th>
          <th>Тип</th>
          <th>Създадено от</th>
     </jsp:attribute>
</ts:pagination>

还有我的分页标签

<%@tag description="This is for common pagination" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn"%>
<%-- The list of normal or fragment attributes can be specified here: --%>

<%@attribute name="tableHeaders" fragment="true" required="true"%>
<%@attribute name="allData" required="false" type="java.util.Collection"%>
<%@attribute name="pageNumber" required="false" type="java.lang.Long"%>
<%@attribute name="pageRange" required="false" type="java.lang.Long"%>
<%@attribute name="url" required="false"%>

<c:set target="${paginationModel}" property="objects" value="${(empty allData) ? paginationModel.objects : allData}" />
<c:set target="${paginationModel}" property="pageNumber" value="${(empty pageNumber) ? 1 : pageNumber}" />
<c:set target="${paginationModel}" property="pageRange" value="${(empty pageRange) ? 10 : pageRange}" />
<c:set target="${paginationModel}" property="url" value="${(empty url) ? paginationModel.url : url}"/>

paginationModel

@Named
@SessionScoped
public class PaginationModel implements Serializable {

    private List<List<String>> objects;
    private Long pageNumber;
    private Long pageRange;
    private String url;

    public PaginationModel() {
        objects = new ArrayList<>();
        pageNumber = 1L;
        pageRange = 10L;
        url = "";
    }
    //getters and setters
}

但作为回应,我收到了这个例外

javax.servlet.ServletException:javax.servlet.jsp.JspException:java.lang.NumberFormatException:对于输入字符串:“”

问题在于从pageRange requestParam解析-1 。我尝试更改分页标签,例如:

<c:set target="${paginationModel}" property="pageRange" value="${10}" />

一切都很好,但是当我尝试

<c:set target="${paginationModel}" property="pageRange" value="${pageRange}" />

我收到同样的异常。我尝试在分页标记中调用${pageRange}(并将${10}解析为paginationModel.pageRange)并且输出为

-1 我不明白我的错误在哪里(paginationModel.pageRange的类型为java.lang.Long并且属性 pageRange 已设置 type="java.lang.Long")以及如何修复异常。

4

1 回答 1

0

java.lang.NumberFormatException:对于输入字符串:“”

问题在于从 pageRange requestParam 解析 -1。

这是不正确的。

java.lang.NumberFormatException: For input string: ""是解析""(空字符串)引起的,例如new Long("")。value="${pageRange}"更改为后,您能否检查您的程序是否有效value="${param.pageRange}"

于 2017-06-12T08:05:05.687 回答