Struts ' logic label

Open source projects The best thing is to let us from the project's source code itself perspective of the project, through the source of understanding more is the design of the concept of mastery to improve the overall ability to achieve the goal. Blog is also a good project, you can not engage in web page production people can also through a simple configuration to achieve the purpose of publishing articles on the Web. I've done two projects with struts before, and now I just want to understand it from another angle. Every day to see a bit of struts source, record their own understanding.

One, the definition label file (web.xml)
<taglib>
<taglib-uri>/tags/struts-logic</taglib-uri>
<taglib-location>/WEB-INF/struts-logic.tld</taglib-location>
</taglib>

Second, the reference tag file (JSP file)
<%@ taglib uri= "/tags/struts-logic" prefix= "logic"%>

Iii. Description of the label document (STRUTS-LOGIC.TLD)
(1) Empty label
Class Name: Org.apache.struts.taglib.logic.EmptyTag
Label Body: bodycontent=jsp
Referencing Logic:empty
Attribute Attribute:name,property,scope
Function: To determine whether an object's value is empty

(2) Equal
Class Name: Org.apache.struts.taglib.logic.EqualTag
Label Body: bodycontent=jsp
Referencing logic:equal
Attribute Attribute:cookie,header,name,parameter,property,scope,value
function: equals comparison character

(3) Forward
Org.apache.struts.taglib.logic.ForwardTag
Label Body: bodycontent=empty
Referencing Logic:forward
Attribute Attribute:name
Features: page orientation, find the global forward of the configuration file

(4) Greaterequal
Class Name: Org.apache.struts.taglib.logic.GreaterEqualTag
Label Body: bodycontent=jsp
Referencing logic:greaterequal
Attribute Attribute:cookie,header,name,parameter,property,scope,value
Function: is greater than or equal to the comparison character

(5) GreaterThan
Class Name: Org.apache.struts.taglib.logic.GreaterThanTag
Label Body: bodycontent=jsp
Referencing Logic:greaterthan
Attribute Attribute:cookie,header,name,parameter,property,scope,value
Function: greater than comparison character

(6) Iterator
Class Name: Org.apache.struts.taglib.logic.IterateTag
Label Body: bodycontent=jsp
Referencing Logic:iterator
Attribute Attribute:collection,id,indexid,length,name,offset,property,scope,type
Function: Display list of collection values (lists, ARRAYLIST,HASHMAP, etc.)

(7) Lessequal
Class name Org.apache.struts.taglib.logic.LessEqualTag
Label Body: bodycontent=jsp
Logic:lessequal
Attribute Attribute:cookie,header,name,parameter,property,scope,value
Function: Less than or equal to comparison character

(8) LessThan
Class Name: Org.apache.struts.taglib.logic.LessThanTag
Label Body: bodycontent=jsp
Logic:lessthan
Attribute Attribute:cookie,header,name,parameter,property,scope,value
Function: less than comparison character

(9) match
Class Name: Org.apache.struts.taglib.logic.MatchTag
Label Body: bodycontent=jsp
Referencing Logic:match
Attribute Attribute:cookie,header,location,name,parameter,property,scope,value
Features: Comparing objects

(a) Messagesnotpresent
Class Name: Org.apache.struts.taglib.logic.MessagesNotPresentTag
Tags: bodycontent=jsp
Referencing logic:messagesnotpresent
Attribute Attribute:name,property,message
Function: Actionmessages/actionerrors object does not exist

(one) messagepresent
Class Name: Org.apache.struts.taglib.logic.MessagesPresentTag
Tags: bodycontent=jsp
Referencing logic:messagepresent
Attribute Attribute:name,property,message
Function: Actionmessages/actionerrors object does not exist

(Notempty)
Class Name: Org.apache.struts.taglib.logic.NotEmptyTag
Tags: bodycontent=jsp
Referencing Logic:notempty
Attribute Attribute:name,property,scope
Function: Compare objects to not empty

(notequal)
Class Name: Org.apache.struts.taglib.logic.NotEqualTag
Tags: bodycontent=jsp
Referencing logic:notequal
Attribute Attribute:cookie,header,name,parameter,property,scope,value

(Notmatch)
Class Name: Org.apache.struts.taglib.logic.NotMatchTag
Tags: bodycontent=jsp
Referencing Logic:notmatch
Attribute Attribute:cookie,header,location,name,parameter,property,scope,value
Function: Compare objects for unequal

(notpresent)
Class Name: Org.apache.struts.taglib.logic.NotPresentTag
Tags: bodycontent=jsp
Referencing logic:notpresent
Attribute Attribute:cookie,header,name,parameter,property,role,scope,user
Function: Request object pass parameter does not exist

(present)
Class Name: Org.apache.struts.taglib.logic.PresentTag
Tags: bodycontent=jsp
Referencing logic:present
Attribute Attribute:cookie,header,name,parameter,property,role,scope,user
Function: Request object pass parameter exists

(redirect)
Class Name: Org.apache.struts.taglib.logic.RedirectTag
Tags: bodycontent=jsp
Referencing Logic:redirect
Property Attribute:anchor,forward,href,name,page,paramid,paramname,paramproperty,paramscope,property,scope, Transaction
function; page steering, transitive parameters