1.<logic:equal> and so on比较标签

以下eg都是由一个servlet转发过来的

MyBean mb = new MyBean();

mb.setName("yc");

mb.setCount(200);

request.setAttribute("mybean",mb);

request.getRequestDispatcher("jsp1.jsp").forward(request,response);

eg1：<bean:define id="myint" value="100"/>//当前页面定义一个字符串

<logic:equal name="myint" value="100">

myint=100

</logic:equal>

eg2：<bean:define id="bean3" name="mybean" scope="request"/>//从request上获取bean

<logic:lessThan name="bean3" property="count" value="200.a">//比较bean的count属性和200.a

bean3 LessThan 200.a

</logic:lessThan>

注意：如果两个字符串都能够成功转为数字，则是比较数字的大小，否则像eg2就是比较字符串的大小

eg3：<bean:define id="bean1" name="mybean" property="name" scope="request"/>

<logic:equal name="bean1" value="yc">

name1=yc

</logic:equal>

eg4：<bean:define id="bean2" name="mybean" scope="request"/>

<logic:equal name="bean2" property="name" value="yc">

name2=yc

</logic:equal>

注意：eg3和eg4都是比较bean属性，只是写法不同

eg5：比较请求参数

<logic:equal parameter="id" value="150">

<bean:parameter id="myid" name="id"/>

parameter:<bean:write name="myid"/>=150

</logic:equal>

2.<logic:match>

查看指定字符串是否被包含

<logic:match name="" value="被包含字符串" location="start/end也可以不写，就是任意位置"/>

eg：<bean:define id="bean4" name="mybean" property="name" scope="request"/>

<logic:match name="bean4" value="y" location="start">

yc is start with bean4

</logic:match>

3.< logic:iterator>

a.遍历Vector等集合，value形式的

<logic:iterator id="每个集合的元素" name="集合在当前页面的绑定名" indexId="序号"

offset="起始位置，0开始" length="遍历长度"/>

前提： Vector v = new Vector();

v.add("dog");

v.add("girl");

v.add("bird");

v.add("cat");

request.setAttribute("myvector",v);

request.getRequestDispatcher("jsp1.jsp").forward(request,response);

eg1：<bean:define id="vector1" name="myvector" scope="request"/>

<logic:iterate id="element" name="vector1">

<bean:write name="element"/>

<br />

</logic:iterate>

eg2：<bean:define id="vector2" name="myvector" scope="request"/>

<logic:iterate id="element" name="vector2" indexId="index" offset="1" length="3">

<bean:write name="index"/>.<bean:write name="element"/><br />

</logic:iterate>

b.遍历Map等，key/value形式

只是输出的时候有所不同

<bean:write name="" property="key"/>输出元素的key部分

<bean:write name="" property="value"/>输出元素的value部分

前提： HashMap hm = new HashMap();

hm.put("yc","yuechen");

hm.put("tjs","tianjinsong");

hm.put("xc","xiaocen");

hm.put("xk","xukai");

request.setAttribute("mymap",hm);

eg：<bean:define id="map1" name="mymap" scope="request"/>

<logic:iterate id="element" name="map1" indexId="index">

<bean:write name="index"/>.<bean:write name="element" property="key"/>:<bean:write name="element" property="value"/><br />

</logic:iterate>

c.遍历map中的集合

双层iterator，内层iterator需要加入property="value"

前提： HashMap hm2 = new HashMap();

String[]asia = {"china","japan","korea"};

hm2.put("asia",asia);

String[]erop = {"greman","rasa","england"};

hm2.put("erop",erop);

String[]us = {"usa","canada"};

hm2.put("us",us);

request.setAttribute("country",hm2);

eg：<bean:define id="myc" name="country" scope="request"/>

<logic:iterate id="element" name="country" indexId="index">

<bean:write name="index"/>.<bean:write name="element" property="key"/><br />

<logic:iterate id="inelement" name="element" indexId="inindex" property="value">

-----<bean:write name="inindex"/>.<bean:write name="inelement"/><br />

</logic:iterate>

</logic:iterate>