上一篇中我们已经基于WTP的StructuredTextEditor建立了自己的JSPEditor，这篇将介绍对于我们Editor最重要的数据模型之一：IStructuredDocument（org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocument），下一篇将介绍另外一个IStructuredModel。看一下IStructuredDocument的类型体系如下：
上图中，我们看到了IStructuredDocument的身影，是JFace Text Framework中IDocument接口实现，选中的JobSafeStructureedDocument就是我们要面对的IStructuredDocument实现。
PS：从类型名称就可以猜测的出来，BasicStructuredDocument应该是一个类似于Default Adapter的角色，具体呢？ 自己去看一下^_^
【IStructuredDocument结构－－Composite】
只要是我们观察一下JSP就知道，其他本质上是一个树状结构的文档，怎么来建立这种文档呢？ 很自然的做法是底层用xml来描述JSP，然后建立起这种xml模型，同时建立起我们的Document实现（说明：提到的WTP XML模型会在下一篇中介绍－－》 IStructuredModel）。既然是树状的，那一般而言接口会按照Composite模式来写。我们先看一下一张IStructuredDocument接口示意图吧：
现在，我们暂且需要记住：在WTP世界中，一个页面资源（JSP、html等）可以被描述为一个IStrucuturedDocument，这个document是由若干个IStructuredDocumentRegion组成，每个IStructuredDocumentRegion又会由多个ITextRegion组成。拿一个真实JSP示意一把：
提到Composite模式，现在我们就看一下谁是里面的节点（Node）、谁又是树枝节点（Container Node）。到目前我们猜测ITextRegion应该是普通节点，IStructuredDocumentRegion应该是树枝节点，我们看一下IStructuredDocumentRegion的sub type图：
更准确说：ITextRegion是节点，ITextRegionCollection是树枝节点（我们认为IStructuredDocumentRegion是树枝节点问题也不大^_^）。
【IStructuredDocument创建和获取方式】
如何来自己创建IStructuredDocument呢？常用的如下几种：
1、IModelManager（org.eclipse.wst.sse.core.internal.provisional.IModelManager）
createStructuredDocumentFor
createNewStructuredDocumentFor
2、IStructuredModel（在已经存在strutured model的情况下，建议使用）
IStructuredModel.getStructuredDocument
或者IStructuredModel.getModelHandler().getDocumentLoader().createNewStructuredDocument
3、IDocumentLoader.createNewStructuredDocument
4、通过IModelHandler（）获取IDocumentLoader，然后创建Structured Document
5、。。。其他方式
示例代码：
1 public void createStructuredDocument(IFile jspFile) {
2 try {
3 //获取org.eclipse.wst.sse.core.internal.provisional.IModelManager
4 IModelManager manager = StructuredModelManager.getModelManager();
5 manager.createNewStructuredDocumentFor(jspFile);
6 manager.createStructuredDocumentFor(jspFile);
7
8 //通过IStructuredModel.getStructuredDocument()
9 IStructuredModel structuredModel = manager.getModelForRead(jspFile);
10 structuredModel.getStructuredDocument();
11
12 //根据文件类型计算对应的IModelHandler，然后获取IDocumentLoader
13 IModelHandler modelHandler = ModelHandlerRegistry.getInstance().getHandlerFor(jspFile);
14 IDocumentLoader documentLoader = modelHandler.getDocumentLoader();
15 documentLoader.createNewStructuredDocument(jspFile);
16
17 //直接调用对应的IModelManager实现（例如解析一般的jsp）
18 new ModelHandlerForJSP().getDocumentLoader().createNewStructuredDocument(jspFile);
19
20 //直接调用对应的IDocumentLoader实现（例如解析一般的jsp）
21 new JSPDocumentLoader().createNewStructuredDocument(jspFile);
22
23 //其他途径
24 } catch (Exception e) {
25 //TODO:log exception
26 }
27 }
注意：
1、IStructuredDocument是相对比较重量级的对象，如果对应的IStructuredModel已经存在，则可以利用IStructuredModel中缓存的IStructuredDocument。（这个在后面介绍IStructuredModel的时候会详细介绍^_^）
2、StructuredModelManager定义在公共包中，IModelManager反而定义在internal包中，它要干吗？？？^_^
【ITextRegion相关】
说明：不要将JFace Text Framework的IRegion和WTP的ITextRegion混淆，但是作用是类似的，核心作用都是提供位置信息。
我们首先来关注一下这个ITextRegion（org.eclipse.wst.sse.core.internal.provisional.text.ITextRegion），毕竟IStructuredDocument树中所有节点都是ITextRegion类型：
我们看到，ITextRegion提供的最核心操作是：位置相关（start、text end、end），这里的所有位置信息是相对于其容器节点IStructuredDocumentRegion的，不是相对于IStructuredDocument（ITextRegionCollection）的；类型相关（getType()）,返回region type。我们看到ITextRegion并没有提供获取文本的方法，有了相对于ITextRegionCollection的位置信息，借助于位置信息用ITextRegionCollection获取不就可以了~_~
既然我们前面说过了，ITextRegion是节点顶级类型，ITextRegionCollection象征着树枝节点（例如IStructuredDocumentRegion），那么如果一种节点类型继承自ITextRegion同时又不是ITextRegionCollection的子类型，那么这种节点就是我们说的树叶节点了（没有孩子^_^）：
看一下上图，子类型名称已经清晰的告诉我们各个子类型是代表什么的了。我们拿几个实际的例子来看一下吧，例子干脆就取自上面图片中的JSP吧：
示例：<html xmlns="http://www.w3.org/1999/xhtml">
分析：
TagOpenRegion --> "<"
TagNameRegion --> "html "
AttributeNameRegion --> "xmlns"
AttributeEqualsRegion --> "="
AttributeValueRegion --> "http://www.w3.org/1999/xhtml"
TagOpenRegion --> ">"
【分析ITextRegion具体子类的类型】
看到上面的分析，我们可能会想，是否需要instanceof（例如 if (instanceof AttributeNameRegion ) .... ）来判断具体叶子节点的类型呢？如果你喜欢，这当然可以；还有一种更方便的方法，那就是借助于ITextRegion.getType()返回接口来判断，示例分别如下：
1 public boolean isTagNameRegion(ITextRegion region) {
2 //实现方式一：instanceof判断
3 if (region instanceof TagNameRegion)
4 return true;
5
6 //实现方式二：type信息判断
7 if (DOMRegionContext.XML_TAG_NAME.equals(region.getType()))
8 return true;
9
10 return false;
11 }
DOMRegionContext（org.eclipse.wst.xml.core.internal.regions.DOMRegionContext）常量接口中枚举了所有的有关XML的text region类型常量：
1 package org.eclipse.wst.xml.core.internal.regions;
2
3 public interface DOMRegionContext {
4
5 public static final String BLOCK_TEXT = "BLOCK_TEXT"; //$NON-NLS-1$
6
7 public static final String UNDEFINED = "UNDEFINED"; //$NON-NLS-1$
8
9 public static final String WHITE_SPACE = "WHITE_SPACE"; //$NON-NLS-1$
10 public static final String XML_ATTLIST_DECL_CLOSE = "XML_ATTLIST_DECL_CLOSE"; //$NON-NLS-1$
11 public static final String XML_ATTLIST_DECL_CONTENT = "XML_ATTLIST_DECL_CONTENT"; //$NON-NLS-1$
12 public static final String XML_ATTLIST_DECL_NAME = "XML_ATTLIST_DECL_NAME"; //$NON-NLS-1$
13
14 public static final String XML_ATTLIST_DECLARATION = "XML_ATTLIST_DECLARATION"; //$NON-NLS-1$
15 public static final String XML_CDATA_CLOSE = "XML_CDATA_CLOSE"; //$NON-NLS-1$
16 public static final String XML_CDATA_OPEN = "XML_CDATA_OPEN"; //$NON-NLS-1$
17 public static final String XML_CDATA_TEXT = "XML_CDATA_TEXT"; //$NON-NLS-1$
18 public static final String XML_CHAR_REFERENCE = "XML_CHAR_REFERENCE"; //$NON-NLS-1$
19 public static final String XML_COMMENT_CLOSE = "XML_COMMENT_CLOSE"; //$NON-NLS-1$
20
21 public static final String XML_COMMENT_OPEN = "XML_COMMENT_OPEN"; //$NON-NLS-1$
22 public static final String XML_COMMENT_TEXT = "XML_COMMENT_TEXT"; //$NON-NLS-1$
23
24 public static final String XML_CONTENT = "XML_CONTENT"; //$NON-NLS-1$
25 public static final String XML_DECLARATION_CLOSE = "XML_DECLARATION_CLOSE"; //$NON-NLS-1$
26
27 public static final String XML_DECLARATION_OPEN = "XML_DECLARATION_OPEN"; //$NON-NLS-1$
28
29 public static final String XML_DOCTYPE_DECLARATION = "XML_DOCTYPE_DECLARATION"; //$NON-NLS-1$
30 public static final String XML_DOCTYPE_DECLARATION_CLOSE = "XML_DOCTYPE_DECLARATION_CLOSE"; //$NON-NLS-1$
31 public static final String XML_DOCTYPE_EXTERNAL_ID_PUBLIC = "XML_DOCTYPE_EXTERNAL_ID_PUBLIC"; //$NON-NLS-1$
32 public static final String XML_DOCTYPE_EXTERNAL_ID_PUBREF = "XML_DOCTYPE_EXTERNAL_ID_PUBREF"; //$NON-NLS-1$
33 public static final String XML_DOCTYPE_EXTERNAL_ID_SYSREF = "XML_DOCTYPE_EXTERNAL_ID_SYSREF"; //$NON-NLS-1$
34 public static final String XML_DOCTYPE_EXTERNAL_ID_SYSTEM = "XML_DOCTYPE_EXTERNAL_ID_SYSTEM"; //$NON-NLS-1$
35 public static final String XML_DOCTYPE_INTERNAL_SUBSET = "XML_DOCTYPE_INTERNAL_SUBSET"; //$NON-NLS-1$
36 public static final String XML_DOCTYPE_NAME = "XML_DOCTYPE_NAME"; //$NON-NLS-1$
37 public static final String XML_ELEMENT_DECL_CLOSE = "XML_ELEMENT_DECL_CLOSE"; //$NON-NLS-1$
38 public static final String XML_ELEMENT_DECL_CONTENT = "XML_ELEMENT_DECL_CONTENT"; //$NON-NLS-1$
39 public static final String XML_ELEMENT_DECL_NAME = "XML_ELEMENT_DECL_NAME"; //$NON-NLS-1$
40
41 public static final String XML_ELEMENT_DECLARATION = "XML_ELEMENT_DECLARATION"; //$NON-NLS-1$
42 public static final String XML_EMPTY_TAG_CLOSE = "XML_EMPTY_TAG_CLOSE"; //$NON-NLS-1$
43 public static final String XML_END_TAG_OPEN = "XML_END_TAG_OPEN"; //$NON-NLS-1$
44 public static final String XML_ENTITY_REFERENCE = "XML_ENTITY_REFERENCE"; //$NON-NLS-1$
45
46 public static final String XML_PE_REFERENCE = "XML_PE_REFERENCE"; //$NON-NLS-1$
47 public static final String XML_PI_CLOSE = "XML_PI_CLOSE"; //$NON-NLS-1$
48 public static final String XML_PI_CONTENT = "XML_PI_CONTENT"; //$NON-NLS-1$
49 public static final String XML_PI_OPEN = "XML_PI_OPEN"; //$NON-NLS-1$
50 public static final String XML_TAG_ATTRIBUTE_EQUALS = "XML_TAG_ATTRIBUTE_EQUALS"; //$NON-NLS-1$
51 public static final String XML_TAG_ATTRIBUTE_NAME = "XML_TAG_ATTRIBUTE_NAME"; //$NON-NLS-1$
52 public static final String XML_TAG_ATTRIBUTE_VALUE = "XML_TAG_ATTRIBUTE_VALUE"; //$NON-NLS-1$
53 public static final String XML_TAG_CLOSE = "XML_TAG_CLOSE"; //$NON-NLS-1$
54 public static final String XML_TAG_NAME = "XML_TAG_NAME"; //$NON-NLS-1$
55
56 public static final String XML_TAG_OPEN = "XML_TAG_OPEN"; //$NON-NLS-1$
57 }
DOMJSPRegionContexts（org.eclipse.jst.jsp.core.internal.regions.DOMJSPRegionContexts）常量接口中枚举了所有的有关JSP的text region类型常量：
1 public interface DOMJSPRegionContexts extends DOMRegionContext {
2 public static final String JSP_CLOSE = "JSP_CLOSE"; //$NON-NLS-1$
3 public static final String JSP_COMMENT_CLOSE = "JSP_COMMENT_CLOSE"; //$NON-NLS-1$
4
5 public static final String JSP_COMMENT_OPEN = "JSP_COMMENT_OPEN"; //$NON-NLS-1$
6 public static final String JSP_COMMENT_TEXT = "JSP_COMMENT_TEXT"; //$NON-NLS-1$
7
8 public static final String JSP_CONTENT = "JSP_CONTENT"; //$NON-NLS-1$
9 public static final String JSP_DECLARATION_OPEN = "JSP_DECLARATION_OPEN"; //$NON-NLS-1$
10 public static final String JSP_DIRECTIVE_CLOSE = "JSP_DIRECTIVE_CLOSE"; //$NON-NLS-1$
11 public static final String JSP_DIRECTIVE_NAME = "JSP_DIRECTIVE_NAME"; //$NON-NLS-1$
12
13 public static final String JSP_DIRECTIVE_OPEN = "JSP_DIRECTIVE_OPEN"; //$NON-NLS-1$
14 public static final String JSP_EL_CLOSE = "JSP_EL_CLOSE"; //$NON-NLS-1$
15 public static final String JSP_EL_CONTENT = "JSP_EL_CONTENT"; //$NON-NLS-1$
16 public static final String JSP_EL_DQUOTE = "JSP_EL_DQUOTE"; //$NON-NLS-1$
17
18 public static final String JSP_EL_OPEN = "JSP_EL_OPEN"; //$NON-NLS-1$
19 public static final String JSP_EL_QUOTED_CONTENT = "JSP_EL_QUOTED_CONTENT"; //$NON-NLS-1$
20 public static final String JSP_EL_SQUOTE = "JSP_EL_SQUOTE"; //$NON-NLS-1$
21 public static final String JSP_EXPRESSION_OPEN = "JSP_EXPRESSION_OPEN"; //$NON-NLS-1$
22
23 public static final String JSP_ROOT_TAG_NAME = "JSP_ROOT_TAG_NAME"; //$NON-NLS-1$
24
25 public static final String JSP_SCRIPTLET_OPEN = "JSP_SCRIPTLET_OPEN"; //$NON-NLS-1$
26 public static final String JSP_VBL_CLOSE = "JSP_VBL_CLOSE"; //$NON-NLS-1$
27 public static final String JSP_VBL_CONTENT = "JSP_VBL_CONTENT"; //$NON-NLS-1$
28 public static final String JSP_VBL_DQUOTE = "JSP_VBL_DQUOTE"; //$NON-NLS-1$
29 public static final String JSP_VBL_OPEN = "JSP_VBL_OPEN"; //$NON-NLS-1$
30 public static final String JSP_VBL_QUOTED_CONTENT = "JSP_VBL_QUOTED_CONTENT"; //$NON-NLS-1$
31 public static final String JSP_VBL_SQUOTE = "JSP_VBL_SQUOTE"; //$NON-NLS-1$
32 public static final String XML_TAG_ATTRIBUTE_VALUE_DQUOTE = "XML_TAG_ATTRIBUTE_VALUE_DQUOTE"; //$NON-NLS-1$
33
34 public static final String XML_TAG_ATTRIBUTE_VALUE_SQUOTE = "XML_TAG_ATTRIBUTE_VALUE_SQUOTE"; //$NON-NLS-1$
35 }
36
CSSRegionContexts（org.eclipse.wst.css.core.internal.parserz.CSSRegionContexts）常量接口中枚举了所有的有关CSS的text region类型常量：
1 public interface CSSRegionContexts {
2 public static final String CSS_COMMENT = "COMMENT"; //$NON-NLS-1$
3 public static final String CSS_CDO = "CDO"; //$NON-NLS-1$
4 public static final String CSS_CDC = "CDC"; //$NON-NLS-1$
5 public static final String CSS_S = "S"; //$NON-NLS-1$
6
7 public static final String CSS_DELIMITER = "DELIMITER"; //$NON-NLS-1$
8 public static final String CSS_LBRACE = "LBRACE"; //$NON-NLS-1$
9 public static final String CSS_RBRACE = "RBRACE"; //$NON-NLS-1$
10
11 public static final String CSS_IMPORT = "IMPORT"; //$NON-NLS-1$
12 public static final String CSS_PAGE = "PAGE"; //$NON-NLS-1$
13 public static final String CSS_MEDIA = "MEDIA"; //$NON-NLS-1$
14 public static final String CSS_FONT_FACE = "FONT_FACE"; //$NON-NLS-1$
15 public static final String CSS_CHARSET = "CHARSET"; //$NON-NLS-1$
16 public static final String CSS_ATKEYWORD = "ATKEYWORD"; //$NON-NLS-1$
17
18 public static final String CSS_STRING = "STRING"; //$NON-NLS-1$
19 public static final String CSS_URI = "URI"; //$NON-NLS-1$
20 public static final String CSS_MEDIUM = "MEDIUM"; //$NON-NLS-1$
21 public static final String CSS_MEDIA_SEPARATOR = "MEDIA_SEPARATOR"; //$NON-NLS-1$
22
23 public static final String CSS_CHARSET_NAME = "CHARSET_NAME"; //$NON-NLS-1$
24
25 public static final String CSS_PAGE_SELECTOR = "CSS_PAGE_SELECTOR"; //$NON-NLS-1$
26
27 public static final String CSS_SELECTOR_ELEMENT_NAME = "SELECTOR_ELEMENT_NAME"; //$NON-NLS-1$
28 public static final String CSS_SELECTOR_UNIVERSAL = "SELECTOR_UNIVERSAL"; //$NON-NLS-1$
29 public static final String CSS_SELECTOR_PSEUDO = "SELECTOR_PSEUDO"; //$NON-NLS-1$
30 public static final String CSS_SELECTOR_CLASS = "SELECTOR_CLASS"; //$NON-NLS-1$
31 public static final String CSS_SELECTOR_ID = "SELECTOR_ID"; //$NON-NLS-1$
32 public static final String CSS_SELECTOR_COMBINATOR = "SELECTOR_COMBINATOR"; //$NON-NLS-1$
33 public static final String CSS_SELECTOR_SEPARATOR = "SELECTOR_SEPARATOR"; //$NON-NLS-1$
34
35 public static final String CSS_SELECTOR_ATTRIBUTE_START = "SELECTOR_ATTRIBUTE_START"; //$NON-NLS-1$
36 public static final String CSS_SELECTOR_ATTRIBUTE_END = "SELECTOR_ATTRIBUTE_END"; //$NON-NLS-1$
37 public static final String CSS_SELECTOR_ATTRIBUTE_NAME = "SELECTOR_ATTRIBUTE_NAME"; //$NON-NLS-1$
38 public static final String CSS_SELECTOR_ATTRIBUTE_VALUE = "SELECTOR_ATTRIBUTE_VALUE"; //$NON-NLS-1$
39 public static final String CSS_SELECTOR_ATTRIBUTE_OPERATOR = "SELECTOR_ATTRIBUTE_OPERATOR"; //$NON-NLS-1$
40
41 public static final String CSS_DECLARATION_PROPERTY = "DECLARATION_PROPERTY"; //$NON-NLS-1$
42 public static final String CSS_DECLARATION_SEPARATOR = "DECLARATION_SEPARATOR"; //$NON-NLS-1$
43 public static final String CSS_DECLARATION_DELIMITER = "DECLARATION_DELIMITER"; //$NON-NLS-1$
44 public static final String CSS_DECLARATION_VALUE_IDENT = "DECLARATION_VALUE_IDENT"; //$NON-NLS-1$
45 public static final String CSS_DECLARATION_VALUE_DIMENSION = "DECLARATION_VALUE_DIMENSION"; //$NON-NLS-1$
46 public static final String CSS_DECLARATION_VALUE_PERCENTAGE = "DECLARATION_VALUE_PERCENTAGE"; //$NON-NLS-1$
47 public static final String CSS_DECLARATION_VALUE_NUMBER = "DECLARATION_VALUE_NUMBER"; //$NON-NLS-1$
48 public static final String CSS_DECLARATION_VALUE_FUNCTION = "DECLARATION_VALUE_FUNCTION"; //$NON-NLS-1$
49 public static final String CSS_DECLARATION_VALUE_PARENTHESIS_CLOSE = "DECLARATION_VALUE_PARENTHESIS_CLOSE"; //$NON-NLS-1$
50 public static final String CSS_DECLARATION_VALUE_STRING = "DECLARATION_VALUE_STRING"; //$NON-NLS-1$
51 public static final String CSS_DECLARATION_VALUE_URI = "DECLARATION_VALUE_URI"; //$NON-NLS-1$
52 public static final String CSS_DECLARATION_VALUE_HASH = "DECLARATION_VALUE_HASH"; //$NON-NLS-1$
53 public static final String CSS_DECLARATION_VALUE_UNICODE_RANGE = "DECLARATION_VALUE_UNICODE_RANGE"; //$NON-NLS-1$
54 public static final String CSS_DECLARATION_VALUE_IMPORTANT = "CSS_DECLARATION_VALUE_IMPORTANT"; //$NON-NLS-1$
55 public static final String CSS_DECLARATION_VALUE_OPERATOR = "DECLARATION_VALUE_OPERATOR"; //$NON-NLS-1$
56 public static final String CSS_DECLARATION_VALUE_S = "DECLARATION_VALUE_S"; //$NON-NLS-1$
57
58 public static final String CSS_UNKNOWN = "UNKNOWN"; //$NON-NLS-1$
59
60 // For null object : CSSTokenizer never set this value
61 public static final String CSS_UNDEFINED = "UNDEFINED"; //$NON-NLS-1$
62 /**
63 * currently provided this field but may be removed in future.
64 */
65 public static final String CSS_FOREIGN_ELEMENT = "FOREIGN_ELEMENT"; //$NON-NLS-1$
66 }
JSPedCSSRegionContexts（org.eclipse.jst.jsp.css.core.internal.parserz.JSPedCSSRegionContexts）常量接口中枚举了所有的有关JSP和CSS嵌套情况下的text region类型常量：
1 public interface JSPedCSSRegionContexts extends CSSRegionContexts {
2 public static final String CSS_JSP_EXP = "CSS_JSP_EXP"; //$NON-NLS-1$
3 public static final String CSS_JSP_EL = CSSRegionContexts.CSS_FOREIGN_ELEMENT; //$NON-NLS-1$
4 public static final String CSS_JSP_SCRIPTLET = "CSS_JSP_SCRIPTLET"; //$NON-NLS-1$
5 public static final String CSS_JSP_DIRECTIVE = "CSS_JSP_DIRECTIVE"; //$NON-NLS-1$
6 public static final String CSS_JSP_DECL = "CSS_JSP_DECL"; //$NON-NLS-1$
7 public static final String CSS_JSP_END = "CSS_JSP_END"; //$NON-NLS-1$
8 public static final String CSS_EL_END = "CSS_EL_END"; //$NON-NLS-1$
9 public static final String CSS_JSP_COMMENT_END = "CSS_JSP_COMMENT_END"; //$NON-NLS-1$
10 public static final String CSS_JSP_COMMENT = "CSS_JSP_COMMENT"; //$NON-NLS-1$
11 }
说明：建议使用ITextRegion.getType()和DOMRegionContext（DOMJSPRegionContexts、CSSRegionContexts、JSPedCSSRegionContexts）做text region的类型分析。为什么呢？像TagNameRegion...其实是ITextRegion的内部实现类型，不应该视为对外暴露的类型，基于接口编程的原则建议我们使用ITextRegion^_^；WTP在为每种ITextRegion的内部实现设定了一个型别码，这使得我们用ITextRegion超类型来判断其具体的实际实现类型成为可能^_^ （PS：有兴趣的哥们，可以看一下有关子类型和类型型别码的资料，这是一个我们经常要面对的东西，隐藏了设计技巧^_^）
【IStructuredDocumentRegion相关】
我们看到，IStructuredDocumentRegion继承自ITextRegionCollection，是一种特殊的树枝节点。上图中的XMLStructuredDocumentRegion是我们最常用的IStructuredDocumentRegion实现。
首先看一下ITextRegionCollection提供的核心操作：
看的出来，提供的核心操作基本上是围绕子text region展开的，具体请翻阅对应的wtp源码！！！常用的如下：
1、getRegions()：返回组成当前text region collection的text region列表
2、getText(ITextRegion)、getFullText(ITextRegion)：获取特定子text region的文本，前者不包含空格
3、getRegionAtCharacterOffset(int)：返回指定位置（相对于collection的位置）的子text region
接着看一下，IStructuredDocumentRegion接口提供的操作：
看的出来，IStructuredDocumentRegion提供了如下几类操作：
1、遍历相关：getParentDocument()、getPrevious()、getNext()，非常常用！！！ 对应set...
2、修改内容操作：addRegion...
【IStructuredDocument核心操作】
IStructuredDocument提供的核心操作基本为三类类：
1、定位IStructuredDocumentRegion：前面说过IStructuredDocument是由一系列IStructuredDocumentRegion组成，由树状结构的顶点获取一级节点这是很应该的^_^ 常用操作如下：
IStructuredDocumentRegion[] getStructuredDocumentRegions();
IStructuredDocumentRegion getFirstStructuredDocumentRegion();
IStructuredDocumentRegion getLastStructuredDocumentRegion();
IStructuredDocumentRegion getRegionAtCharacterOffset(int offset);
IStructuredDocumentRegion[] getStructuredDocumentRegions(int offset, int length);
2、修改document文本内容：类似于JFace中IDocument.replace(int offset, int length, String text)。
3、Document Listener相关：这个特性这边不做详细阐述，后面到我们进一步定制WTP JSP编辑器的时候再讨论如何使用它。很显然，和JFace中的IDocumentListener机制原理类似，是一个典型的Obsever实现，将Document自身核心逻辑和Document变化处理逻辑进行松耦合处理。
【后记】
在这篇随笔中，我们详细地讨论了WTP中的JFace IDocument实现 －－》 IStructuredDocument！！！现在我们再看文章开头的两幅图，应该比较清楚了吧^_^ 再回顾一下吧：
1、IStructuredDocument结构分析，Composite实现，并着重分析里里面的节点、叶子节点、树枝节点
2、如果创建和获取IStructuredDocument实例，并强调了其重量级对象的特性
3、相关接口的核心操作说明，例如遍历，通过IStructuredDocument可以拿到你想要的IStructuredDocumentRegion，通过IStructuredDocumentRegion可以拿到你想要的ITextRegion，还说明了如何分析ITextRegion的类型。
题目：给定一个工作区中的jsp文件，让你分析该jsp文件，然后打印出来里面涉及到的所有tag name
办法：
1、通过IFile构造对应的IStructuredDocument实例
2、遍历IStructuredDocument， 获取IStructuredDocumentRegion列表
3、分析IStructuredDocumentRegion，获取其含有的ITextRegion列表
4、找出类型为DOMRegionContext.XML_TAG_NAME的text region，然后通过ITextRegionCollection.getText(ITextRegion containedRegion)获取标签名称
^_^，了解了WTP IStructuredDocument实现，是不是觉得看WTP中的页面资源文件更透彻些了呢？如果再了解一下后门的IStructuredModel，你会觉得更透彻^_^
PS：在下一篇中，我们将开发一个Structured Document分析视图。有关WTP Editor定制的具体细节还要再放置到更后门的篇幅去讲，个人觉得如果对WTP IStructuredDocument和IStructuredModel这两个核心数据模型不够熟悉，你想定制WTP的已有功能....举步维艰！
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