Configure DTD of XML file

Catalog

1. understand dtd Mind maps

2.XML What is it? ？

3.XML The role of ：

4. Why study XML

5. The standard XML The format of ：

1. There is and only one root element , On the way

2.XML Label case sensitive , For example “filter” and “Filter”、“listener” and “Listener” It's not the same thing , So different

3. Use the end tag correctly , There is a beginning in the figure , Existing end , Similar to double label

4. Nesting labels correctly , In the figure config It's nested in action,action It's nested in forward

5. Legal tag name used , In the picture action and forward It's the tag name

 6. Define valid properties

6. Two examples ：

---

1. understand dtd Mind maps

2.XML What is it? ？

1. XML Extensible markup language （EXtensible Markup Language）
2. XML It's a markup language , similar HTML
3. XML The purpose of the design is To transmit data , Instead of displaying data
4. XML The label is not predefined . You need to define your own tags .
5. XML Designed to be self-descriptive .
6. XML yes W3C The recommended standard of

3.XML The role of ：

Not just configuration , And for cross language data interaction

4. Why study XML

stay XML In language , It allows users to customize tags . A label is used to describe a piece of data ; A tag can be divided into start tag and end tag , Between the start tag and the end tag , You can also use other tags to describe other data , So as to realize the description of data relationship .

5. The standard XML The format of ：

1. There is and only one root element , On the way <!DOCTYPE root[]>

2.XML Label case sensitive , For example “filter” and “Filter”、“listener” and “Listener” It's not the same thing , So different

3. Use the end tag correctly , In the picture <config></config> There is a beginning , Existing end . for instance ： Be similar to HTML Double label

4. Nesting labels correctly , In the figure config It's nested in action,action It's nested in forward

5. Legal tag name used , In the picture action and forward It's the tag name ,path and type This is the property

 6. Define valid properties

6. Two examples ：

In the picture above root Namely config

element-name Is nested relationship ,

Like config yes dtd The head of the ,config There are two aciton,action There are two forward

<?xml version="1.0" encoding="UTF-8"?>
	<!--
		config label : Can contain 0~N individual action label 
	-->
	<!DOCTYPE config[
		<!ELEMENT config (action*)>
		<!ELEMENT ation (forward*)>
		
		
		<!ATTLIST action
		path CDATA #REQUIRED
		type CDATA #REQUIRED
		>
		<!ATTLIST forward
		name CDATA #REQUIRED
		path CDATA #REQUIRED
		redirect (true|false) 'true'
		>
	]>
<config>
	<!--
		action label : Can be full of 0~N individual forward label  path: With / Starting string , And the value must be unique   Non empty  , The path corresponding to the sub controller 
		type: character string , Non empty , The full class name of the sub controller 
	-->
	<action path="/registerAction" type="test.action.RegisterAction">
		<forward name="success" path="/index.jsp" redirect="true" />
		<forward name="failed" path="/register.jsp" redirect="false" />
	</action>
	<action path="/loginAction" type="test.action.LoginAction">
		<forward name="a" path="/index.jsp" redirect="false" />
		<forward name="b" path="/welcome.jsp" redirect="true" />
	</action>
</config>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE persons[
	<!ELEMENT persons (person+)>
	<!ELEMENT person (name,age,contact,br*)>
	<!ELEMENT name (#PCDATA)>
	<!ELEMENT age (#PCDATA)>
	<!ELEMENT contact (phone|email)>
	<!ELEMENT br EMPTY>
	<!ATTLIST person
	  pid ID #REQUIRED
	  sex ( male | Woman ) ' male '
	  qq CDATA #IMPLIED
	  parent IDREF #IMPLIED
	>
]>
<persons>
	<person pid="p1" sex=" male " qq="aaa" parent="p2">
		<name> Zhang Xiaoming </name>
		<age>10</age>
		<contact>
			<phone>1234567</phone>
		</contact>
		<br/>
	</person>
	<person pid="p2">
		<name> Zhang Daming </name>
		<age>35</age>
		<contact>
			<email>[email protected]</email>
		</contact>
	</person>
</persons>