如何在JSP中进行分页...？

Question

请不要低估我的问题,因为我是JSP/JavaEE的新手.

我看了很多关于JSTL,Pagination的教程,但是我无法做出适当的想法来进行分页......是否有一种方法来执行分页......？

在我的程序中,我使用java类从数据库中检索搜索结果的记录,并将它们放入ArrayList并将ArrayList返回给Servlet.然后将收到的ArrayList对象分配给这样的应用程序属性

request.setAttribute("Results", results_List);

然后使用请求调度程序,我正在加载显示jsp页面的结果.

RequestDispatcher rd = request.getRequestDispatcher("searchresults.jsp");
rd.forward(request, response);

所以告诉我下一步做分页我的搜索结果..

Answer 1

在Servlet中,我们首先获取'page'参数的值并将其存储在'page'变量中.我们希望每页显示五(5)条记录,我们将其作为参数传递给viewAllEmployees(offset,5).我们在请求范围中存储三个属性并将请求转发到JSP页面;

Servlet类:

public void doGet(HttpServletRequest request,  HttpServletResponse response)  throws ServletException, IOException {
            int page = 1;
            int recordsPerPage = 5;
            if(request.getParameter("page") != null)
                page = Integer.parseInt(request.getParameter("page"));
            EmployeeDAO dao = new EmployeeDAO();
            List<Employee> list = dao.viewAllEmployees((page-1)*recordsPerPage,
                                     recordsPerPage);
            int noOfRecords = dao.getNoOfRecords();
            int noOfPages = (int) Math.ceil(noOfRecords * 1.0 / recordsPerPage);
            request.setAttribute("employeeList", list);
            request.setAttribute("noOfPages", noOfPages);
            request.setAttribute("currentPage", page);
            RequestDispatcher view = request.getRequestDispatcher("employee.jsp");
            view.forward(request, response);
        }

Jsp文件:

 

<table border="1" cellpadding="5" cellspacing="5">
        <tr>
            <th>Emp ID</th>
            <th>Emp Name</th>
            <th>Salary</th>
            <th>Dept Name</th>
        </tr>
 
        <c:forEach var="employee" items="${employeeList}">
            <tr>
                <td>${employee.employeeId}</td>
                <td>${employee.employeeName}</td>
                <td>${employee.salary}</td>
                <td>${employee.deptName}</td>
            </tr>
        </c:forEach>
    </table>
 
    <%--For displaying Previous link except for the 1st page --%>
    <c:if test="${currentPage != 1}">
        <td><a href="employee.do?page=${currentPage - 1}">Previous</a></td>
    </c:if>
 
    <%--For displaying Page numbers. 
    The when condition does not display a link for the current page--%>
    <table border="1" cellpadding="5" cellspacing="5">
        <tr>
            <c:forEach begin="1" end="${noOfPages}" var="i">
                <c:choose>
                    <c:when test="${currentPage eq i}">
                        <td>${i}</td>
                    </c:when>
                    <c:otherwise>
                        <td><a href="employee.do?page=${i}">${i}</a></td>
                    </c:otherwise>
                </c:choose>
            </c:forEach>
        </tr>
    </table>
     
    <%--For displaying Next link --%>
    <c:if test="${currentPage lt noOfPages}">
        <td><a href="employee.do?page=${currentPage + 1}">Next</a></td>
    </c:if>