小编典典

如何将一个ArrayList分解并显示为多个表列

jsp

我有一个Servlet,它会加载属性文件,并在ArrayList对象中包含100个测试用例名称的列表。加载后,该servlet转发到JSP,该JSP在表中显示该列表。该列表很长,因此我希望以一种优雅的方式将其显示在表中,以便在JSP上分成三列或四列。

我现在要做的是将该列表在servlet中分成三个子列表:

//load properties
Properties props = new Properties();
        ArrayList<String> tests = new ArrayList<String>();
        props.load(getServletContext().getResourceAsStream("/WEB-INF/sailcertifier.properties"));
        Pattern pattern = Pattern.compile("[A-Z]{3}-[0-9]{2}");     
        for (Enumeration<Object> e = props.keys(); e.hasMoreElements();) {
            String key = (String) e.nextElement();
            Matcher m = pattern.matcher(key);
            if (m.find())
                tests.add(key);
        }
        Collections.sort(tests, new TestOrderComparator());
        confBean.setPossibleTests(tests.toArray(new String[tests.size()]));
        int third = tests.size() / 3;
        List<String> testSubset1 = tests.subList(0, third);
        List<String> testSubset2 = tests.subList(third, third * 2);
        List<String> testSubset3 = tests.subList(third * 2, tests.size());
        //store the bean as a request attribute
        request.setAttribute("testSet1", testSubset1.toArray(new String[testSubset1.size()]));
        request.setAttribute("testSet2", testSubset2.toArray(new String[testSubset2.size()]));
        request.setAttribute("testSet3", testSubset3.toArray(new String[testSubset3.size()]));
        request.setAttribute("testsConf", confBean);
        request.setAttribute("certProps", props);
        //forward to tests selection page
        String url = "/sailcertifier/jsp/testsSelection.jsp";
        RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(url);
        response.setContentType("application/javascript");
        try {
            dispatcher.forward(request, response);
        } catch (ServletException e) {
            e.printStackTrace();
        }

在JSP中,我像这样遍历子列表(为每种情况添加一些html元素):

    <table>
        <tr>
            <td style="width: 33%">
                <table>
                    <tr>
                        <td>
                            <c:forEach var="testName" items="${testSet1}">
                                <tr>
                                    <td><label for="${testName}" id=${testName}Label>${testName}</label></td>
                                    <td><input id=${testName} type="checkbox" value=${testName} name="selTest"></input></td>
                                    <td><input id=${testName}Run type="button" value="Run Test" name="runButtons" /></td>
                                    <td><input id=${testName}ManPass type="button" value="Manual Pass" name="manPassButtons"/></td>
                                    <td><div id=${testName}Status style="width:100px"></td>
                                    <td></td>
                                    <td></td>
                                </tr>
                            </c:forEach>
                            <tr><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr>
                        </td>
                    </tr>
                </table>
            </td>
            <td style="width: 33%">
                <table>
                    <tr>
                        <td>
                            <c:forEach var="testName" items="${testSet2}">
                                <tr>
                                    <td><label for="${testName}" id=${testName}Label>${testName}</label></td>
                                    <td><input id=${testName} type="checkbox" value=${testName} name="selTest"></input></td>
                                    <td><input id=${testName}Run type="button" value="Run Test" name="runButtons" /></td>
                                    <td><input id=${testName}ManPass type="button" value="Manual Pass" name="manPassButtons"/></td>
                                    <td><div id=${testName}Status style="width:100px"></td>
                                    <td></td>
                                    <td></td>
                                </tr>
                            </c:forEach>
                            <tr><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr>
                        </td>
                    </tr>
                </table>
            </td>
            <td style="width: 33%">
                <table>
                    <tr>
                        <td>
                            <c:forEach var="testName" items="${testSet3}">
                                <tr>
                                    <td><label for="${testName}" id=${testName}Label>${testName}</label></td>
                                    <td><input id=${testName} type="checkbox" value=${testName} name="selTest"></input></td>
                                    <td><input id=${testName}Run type="button" value="Run Test" name="runButtons" /></td>
                                    <td><input id=${testName}ManPass type="button" value="Manual Pass" name="manPassButtons"/></td>
                                    <td><div id=${testName}Status style="width:100px"></td>
                                    <td></td>
                                </tr>
                            </c:forEach>
                        </td>
                    </tr>
                </table>
            </td>
        </tr>
    </table>

我承认使用三个JSTL进行循环有点难看(尚未弄清楚是否使用完整的原始列表)。是否有更清洁的方法来解决此问题,方法是使用某些jquery插件(例如jquery
grid
plugin
)或其他库(displaytag吗?)为我平均处理分成几行?


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2020-06-08

共1个答案

小编典典

打印a <tr>,然后循环遍历数组列表,然后打印<td>a中的</tr><tr>每一项并打印每 n个
项目,然后结束循环遍历数组列表,最后再打印一次</tr>

例如,每第3个项目就有一个新行:

<table>
    <tr>
        <c:forEach items="${items}" var="item" varStatus="loop">
            <c:if test="${not loop.first and loop.index % 3 == 0}">
                </tr><tr>
            </c:if>
            <td>${item}</td>
        </c:forEach>
    </tr>
</table>

${loop.index}返回当前迭代循环的索引。在% 3将只返回0,如果它是可分割由3没有余(因此,当索引为0,3,6,9,12,等等)。

2020-06-08