页面开发中经常使用到的功能

1.Java链接SqlServer2005

String connectionUrl = "jdbc:sqlserver://192.168.1.252:1433;" +"databaseName=phonesale;user=sa;password=ctct";

Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
con = DriverManager.getConnection(connectionUrl);

2.应用注销：经过超连接访问Servlet注销，跳出框架，跳转到登录页面

HTML:
<a href="/note/login?action=loginout" target="_top">退出系统</a>

Servlet:
request.getSession().removeAttribute("loginFlag");
request.getSession().removeAttribute("UserInfo");
request.getSession().invalidate();
request.getRequestDispatcher("login.jsp").forward(request, response);

JSP:
<%
response.setHeader("Cache-Control","no-cache");
response.setHeader("Cache-Control","no-store");
response.setDateHeader("Expires", 0);
response.setHeader("Pragma","no-cache");
if(session.getAttribute("loginFlag") != "true") {
    response.sendRedirect("/note/login.jsp");
}
%>

3. JSP读取XML文件

1.先导入相关的包
<%@ page javax.xml.parsers.*,org.w3c.dom.*,java.io.*" %>

2.读取xml文件，并循环节点值
<%
            String path1 = request.getRealPath(request.getServletPath());
            String xmlPath = path1.substring(0,path1.lastIndexOf("\\")+1) + "navLink.xml";
            File f = new File(xmlPath);

            //创建一个解析器工厂
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

            //得到一个具体的解析器对象
            DocumentBuilder builder = factory.newDocumentBuilder();

            //对XML文档进行解析，得到Document对象
            Document doc = builder.parse(f);
            doc.normalize();

            //获取全部的book元素列表
            NodeList books = doc.getElementsByTagName("我的报表");
            //out.println(books.getLength());

            for(int i=0; i<books.getLength(); i++) {
                //获取某个元素
                Element e = (Element)books.item(i);
            %>
                <div id="personalSubMenu" class="firstDivOne"><a href='<%=e.getElementsByTagName("url").item(0).getFirstChild().getNodeValue() %>' target="I1"><%=e.getElementsByTagName("name").item(0).getFirstChild().getNodeValue()%></a></div>
            <%
            }
            %>
            <div class="firstDiv" onClick="javascript:show('group');" id="groupChart" name="groupChart">小组报表</div>
            <%
            books = doc.getElementsByTagName("小组报表");
            for(int i=0; i<books.getLength(); i++) {
                //获取某个元素
                Element e = (Element)books.item(i);
            %>
                <div id="GroupSubMenu" class="firstDivOne"><a href='<%=e.getElementsByTagName("url").item(0).getFirstChild().getNodeValue() %>' target="I1"><%=e.getElementsByTagName("name").item(0).getFirstChild().getNodeValue()%></a></div>
            <%
            }

            %>

4.JavaScript 控制菜单的隐藏和显示

<script type="text/JavaScript">
<!--

//隐藏全部的菜单
function hideAll() {

    var obj = document.getElementsByName("personalSubMenu");
    for(i=0; i<obj.length;i++) {
        obj[i].style.display = "none";
    }

    obj = document.getElementsByName("groupSubMenu");
    for(i=0; i<obj.length;i++) {
        obj[i].style.display = "none";
    }

}

//根据传递的参数，控制某个菜单的显示
function show(obj) {

    if(obj=="per") {
        hideAll();
        var obj1 = document.getElementsByName("personalSubMenu");
        for(i=0; i<obj1.length;i++) {
            obj1[i].style.display = "block";
        }
    }

    if(obj=="group") {
        hideAll();
        var obj2 = document.getElementsByName("groupSubMenu");
        for(i=0; i<obj2.length;i++) {
            obj2[i].style.display = "block";
        }
    }

}
//-->
</script>

<div class="firstDiv" onClick="javascript:show('per');" id="personalChart" name="personalChart">我的报表</div>

<div class="firstDiv" onClick="javascript:show('group');" id="groupChart" name="groupChart">小组报表</div>

 5.表单提交前验证

<form name="form1" method="post" action="/chartnew/JFreeChart?action=CircleChart_Group" onSubmit="return check();">
<input type="submit" value="查询">
</form>

<script language="javascript">
    function check() {

        var flag = false;
        var radio = document.getElementsByName("circle");
        var checkbox = document.getElementsByName("data");

        for(i=0; i<radio.length; i++) {
            if(radio[i].checked) {
                flag = true;
            }
        }

        if(!flag) {
            alert("请选择周期！");
            return false;
        }
        flag = false;

        for(i=0; i<checkbox.length; i++) {
            if(checkbox[i].checked) {
                flag = true;
            }
        }
        if(!flag) {
            alert("请选择须要展现的数据！");
            return false;
        }

        return true;
    }
</script>

 6.getElementsByName和getElementById

//获取元素集合，好比像：radio或select元素
document.getElementsByName("tagName");
//获取单个元素，好比像：text等
document.getElementById("tagName");