Class VariableInfo
- java.lang.Object
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- javax.servlet.jsp.tagext.VariableInfo
 
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 public class VariableInfo extends java.lang.ObjectInformation on the scripting variables that are created/modified by a tag (at run-time). This information is provided by TagExtraInfo classes and it is used by the translation phase of JSP.Scripting variables generated by a custom action have an associated scope of either AT_BEGIN, NESTED, or AT_END. The class name (VariableInfo.getClassName) in the returned objects is used to determine the types of the scripting variables. Note that because scripting variables are assigned their values from scoped attributes which cannot be of primitive types, "boxed" types such as java.lang.Integermust be used instead of primitives.The class name may be a Fully Qualified Class Name, or a short class name. If a Fully Qualified Class Name is provided, it should refer to a class that should be in the CLASSPATH for the Web Application (see Servlet 2.4 specification - essentially it is WEB-INF/lib and WEB-INF/classes). Failure to be so will lead to a translation-time error. If a short class name is given in the VariableInfo objects, then the class name must be that of a public class in the context of the import directives of the page where the custom action appears. The class must also be in the CLASSPATH for the Web Application (see Servlet 2.4 specification - essentially it is WEB-INF/lib and WEB-INF/classes). Failure to be so will lead to a translation-time error. Usage Comments Frequently a fully qualified class name will refer to a class that is known to the tag library and thus, delivered in the same JAR file as the tag handlers. In most other remaining cases it will refer to a class that is in the platform on which the JSP processor is built (like J2EE). Using fully qualified class names in this manner makes the usage relatively resistant to configuration errors. A short name is usually generated by the tag library based on some attributes passed through from the custom action user (the author), and it is thus less robust: for instance a missing import directive in the referring JSP page will lead to an invalid short name class and a translation error. Synchronization Protocol The result of the invocation on getVariableInfo is an array of VariableInfo objects. Each such object describes a scripting variable by providing its name, its type, whether the variable is new or not, and what its scope is. Scope is best described through a picture:   The JSP 2.0 specification defines the interpretation of 3 values: - NESTED, if the scripting variable is available between the start tag and the end tag of the action that defines it.
- AT_BEGIN, if the scripting variable is available from the start tag of the action that defines it until the end of the scope.
- AT_END, if the scripting variable is available after the end tag of the action that defines it until the end of the scope.
 
 1 Called afterVariable Synchronization Points Variable Synchronization Points 
 doStartTag() doInitBody() doAfterBody() doEndTag() doTag() Tag 
 AT_BEGIN, NESTED 
 
 
 AT_BEGIN, AT_END 
 
 IterationTag 
 AT_BEGIN, NESTED 
 
 AT_BEGIN, NESTED 
 AT_BEGIN, AT_END 
 
 BodyTag 
 AT_BEGIN, NESTED1 
 AT_BEGIN, NESTED1 
 AT_BEGIN, NESTED 
 AT_BEGIN, AT_END 
 
 SimpleTag 
 
 
 
 
 AT_BEGIN, AT_END 
 doStartTag()ifEVAL_BODY_INCLUDEis returned, or afterdoInitBody()otherwise.Variable Information in the TLD Scripting variable information can also be encoded directly for most cases into the Tag Library Descriptor using the <variable> subelement of the <tag> element. See the JSP specification. 
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Field SummaryFields Modifier and Type Field Description static intAT_BEGINScope information that scripting variable is visible after start tag.static intAT_ENDScope information that scripting variable is visible after end tag.static intNESTEDScope information that scripting variable is visible only within the start/end tags.
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Constructor SummaryConstructors Constructor Description VariableInfo(java.lang.String varName, java.lang.String className, boolean declare, int scope)Constructor These objects can be created (at translation time) by the TagExtraInfo instances.
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Method SummaryAll Methods Instance Methods Concrete Methods Modifier and Type Method Description java.lang.StringgetClassName()Returns the type of this variable.booleangetDeclare()Returns whether this is a new variable.intgetScope()Returns the lexical scope of the variable.java.lang.StringgetVarName()Returns the name of the scripting variable.
 
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Field Detail- 
NESTEDpublic static final int NESTED Scope information that scripting variable is visible only within the start/end tags.- See Also:
- Constant Field Values
 
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AT_BEGINpublic static final int AT_BEGIN Scope information that scripting variable is visible after start tag.- See Also:
- Constant Field Values
 
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AT_ENDpublic static final int AT_END Scope information that scripting variable is visible after end tag.- See Also:
- Constant Field Values
 
 
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Constructor Detail- 
VariableInfopublic VariableInfo(java.lang.String varName, java.lang.String className, boolean declare, int scope)Constructor These objects can be created (at translation time) by the TagExtraInfo instances.- Parameters:
- varName- The name of the scripting variable
- className- The type of this variable
- declare- If true, it is a new variable (in some languages this will require a declaration)
- scope- Indication on the lexical scope of the variable
 
 
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Method Detail- 
getVarNamepublic java.lang.String getVarName() Returns the name of the scripting variable.- Returns:
- the name of the scripting variable
 
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getClassNamepublic java.lang.String getClassName() Returns the type of this variable.- Returns:
- the type of this variable
 
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getDeclarepublic boolean getDeclare() Returns whether this is a new variable. If so, in some languages this will require a declaration.- Returns:
- whether this is a new variable.
 
 
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