Hyperic HQ Plugin API v. 4.4.0.2

org.hyperic.hq.ui.taglib
Class ConstantsTag

java.lang.Object
  extended by javax.servlet.jsp.tagext.TagSupport
      extended by org.hyperic.hq.ui.taglib.ConstantsTag
All Implemented Interfaces:
java.io.Serializable, javax.servlet.jsp.tagext.IterationTag, javax.servlet.jsp.tagext.JspTag, javax.servlet.jsp.tagext.Tag
Direct Known Subclasses:
ConstantsDiagTag

public class ConstantsTag
extends javax.servlet.jsp.tagext.TagSupport

A sensible way to handle constants in a webapp is to define a bean that holds all of the constants as attributes. However, Java programmers have a propensity for creating constants as classes that have the values defined static final members. This tag exposes these attribute handles to save the developer from having to read the constants class source code to determine the returned values. This way the JSP source and the backend bean (and/or bean handlers) have a consistent interface to the constants class. Under the hood, the tag uses reflection to build a map of names and values. The map is cached to save the expense of repeated runtime reflection. Usage: Suppose you have a class com.example.Constants: public class Constants { public static final int WARMRESTART = 0; public static final int COLDRESTART = 1; public static final int HARDRESTART = 2; public static final String RO = "rock"; public static final String SHAM = "paper"; public static final String BO = "scissors"; } and you want to uniformly access the symbold names in the jsp as you would in your Java classes. Use this tag. <%@ taglib uri="/WEB-INF/constants.tld" prefix="constants" %> ... someplace where a constant needs to be accessed: Important: This usage assumes the class to access is specified in a web-xml/context-param The alternate form can be used to accomadate having multiple constants classes. Another usage is set attributes, within an optionally specified scope or just to put it in the page scope. Either way, at sometime later, you can do this

See Also:
Serialized Form

Field Summary
protected static java.util.HashMap constants
           
static java.lang.String constantsClassNameParam
           
 
Fields inherited from class javax.servlet.jsp.tagext.TagSupport
id, pageContext
 
Fields inherited from interface javax.servlet.jsp.tagext.IterationTag
EVAL_BODY_AGAIN
 
Fields inherited from interface javax.servlet.jsp.tagext.Tag
EVAL_BODY_INCLUDE, EVAL_PAGE, SKIP_BODY, SKIP_PAGE
 
Constructor Summary
ConstantsTag()
           
 
Method Summary
protected  void die(javax.servlet.jsp.JspWriter out)
           
protected  void die(javax.servlet.jsp.JspWriter out, java.lang.String err)
           
 int doEndTag()
           
protected  void doOutput(java.util.HashMap fieldMap, javax.servlet.jsp.JspWriter out)
           
protected  void doSet(java.util.HashMap fieldMap)
           
 java.lang.String getClassname()
           
 boolean getFailmode()
           
 java.lang.String getScope()
           
 java.lang.String getSymbol()
           
 java.lang.String getVar()
           
 void release()
           
 void setClassname(java.lang.String aClass)
           
 void setFailmode(boolean theFailmode)
           
 void setScope(java.lang.String aScopeName)
           
 void setSymbol(java.lang.String aSymbol)
           
 void setVar(java.lang.String aVar)
           
protected  boolean validate(javax.servlet.jsp.JspWriter out)
          Method validate Checks for broken configuration/attribute combinations
 
Methods inherited from class javax.servlet.jsp.tagext.TagSupport
doAfterBody, doStartTag, findAncestorWithClass, getId, getParent, getValue, getValues, removeValue, setId, setPageContext, setParent, setValue
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

constants

protected static java.util.HashMap constants

constantsClassNameParam

public static final java.lang.String constantsClassNameParam
See Also:
Constant Field Values
Constructor Detail

ConstantsTag

public ConstantsTag()
Method Detail

setClassname

public void setClassname(java.lang.String aClass)

getClassname

public java.lang.String getClassname()

setVar

public void setVar(java.lang.String aVar)

getVar

public java.lang.String getVar()

setFailmode

public void setFailmode(boolean theFailmode)

getFailmode

public boolean getFailmode()

setSymbol

public void setSymbol(java.lang.String aSymbol)

getSymbol

public java.lang.String getSymbol()

setScope

public void setScope(java.lang.String aScopeName)

getScope

public java.lang.String getScope()

release

public void release()
Specified by:
release in interface javax.servlet.jsp.tagext.Tag
Overrides:
release in class javax.servlet.jsp.tagext.TagSupport

doEndTag

public int doEndTag()
             throws javax.servlet.jsp.JspException
Specified by:
doEndTag in interface javax.servlet.jsp.tagext.Tag
Overrides:
doEndTag in class javax.servlet.jsp.tagext.TagSupport
Throws:
javax.servlet.jsp.JspException

doOutput

protected void doOutput(java.util.HashMap fieldMap,
                        javax.servlet.jsp.JspWriter out)
                 throws java.io.IOException
Throws:
java.io.IOException

doSet

protected void doSet(java.util.HashMap fieldMap)

validate

protected boolean validate(javax.servlet.jsp.JspWriter out)
                    throws javax.servlet.jsp.JspException
Method validate Checks for broken configuration/attribute combinations

Returns:
true is validation fails
Throws:
javax.servlet.jsp.JspException

die

protected void die(javax.servlet.jsp.JspWriter out)
            throws javax.servlet.jsp.JspException
Throws:
javax.servlet.jsp.JspException

die

protected void die(javax.servlet.jsp.JspWriter out,
                   java.lang.String err)
            throws javax.servlet.jsp.JspException
Throws:
javax.servlet.jsp.JspException

Hyperic HQ Plugin API v. 4.4.0.2

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