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JavaCast

Last updated on May 30, 2024 | Also applies to ColdFusion

CFML Reference User Guide
ColdFusion functions
ColdFusion Tags
1. ColdFusion tag summary
2. ColdFusion tags by category
  1. Application framework tags
    1. cfapplication
    2. cfassociate
    3. cferror
    4. cfimport
    5. cfinterface
    6. cflock
    7. cfscript
    8. cfthread
  2. Communications tags
  3. Database manipulation tags
  4. Data output tags
    1. cfchart
    2. cfchartdata
    3. cfchartseries
    4. cfcol
    5. cfcontent
    6. cfdocument
    7. cfdocumentitem
    8. cfdocumentsection
    9. cfflush
    10. cfheader
    11. cflog
    12. cfoutput
    13. cfpresentation
    14. cfpresentationslide
    15. cfpresenter
    16. cfprocessingdirective
    17. cfprint
    18. cfreport
    19. cfreportparam
    20. cfsilent
    21. cftable
  5. Debugging tags
    1. cfdump
    2. cftimer
    3. cftrace
  6. Exception handling tags
    1. cfcatch
    2. cferror
    3. cffinally
    4. cfrethrow
    5. cfthrow
    6. cftry
  7. Extensibility tags
    1. cfchart
    2. cfchartdata
    3. cfchartseries
    4. cfcollection
    5. cfcomponent
    6. cfexecute
    7. cfftp
    8. function
    9. cfindex
    10. cfinterface
    11. cfinvoke
    12. cfinvokeargument
    13. cfobject
    14. cfproperty
    15. cfreport
    16. cfreportparam
    17. cfreturn
    18. cfsearch
    19. cfsharepoint
    20. cfspreadsheet
    21. cfwddx
    22. cfxml
  8. File management tags
    1. cfdirectory
    2. cffile
    3. cffileupload
    4. cfftp
    5. cfzip
    6. cfzipparam
  9. Flow-control tags
    1. cfabort
    2. cfbreak
    3. cfcase
    4. cfcontinue
    5. cfdefaultcase
    6. cfelse
    7. cfelseif
    8. cfexecute
    9. cfexit
    10. cfif
    11. cfinclude
    12. cflocation
    13. cfloop
    14. cfrethrow
    15. cfswitch
    16. cfthrow
    17. cftry
  10. Forms tags
    1. cfapplet
    2. cfcalendar
    3. cffileupload
    4. cfform
    5. cfformgroup
    6. cfformitem
    7. cfgrid
    8. cfgridcolumn
    9. cfgridrow
    10. cfgridupdate
    11. cfinput
    12. cfpdf
    13. cfpdfform
    14. cfpdfformparam
    15. cfpdfparam
    16. cfpdfsubform
    17. cfselect
    18. cfslider
    19. cftextarea
    20. cftree
    21. cftreeitem
  11. Internet Protocol tags
    1. cfajaximport
    2. cfajaxproxy
    3. cfftp
    4. cffeed
    5. cfimap
    6. cfhttp
    7. cfhttpparam
    8. cfldap
    9. cfmail
    10. cfmailparam
    11. cfmailpart
    12. cfpop
    13. cfsprydataset
  12. Page processing tags
    1. cfcache
    2. cfcontent
    3. cfflush
    4. cfheader
    5. cfhtmlhead
    6. cfinclude
    7. cfprocessingdirective
    8. cfsetting
    9. cfsilent
  13. Security tags
  14. Variable manipulation tags
    1. cfcookie
    2. cfdump
    3. cfparam
    4. cfregistry
    5. cfsavecontent
    6. cfschedule
    7. cfset
    8. cfsetting
  15. Other tags
    1. cfimage
    2. cflog
    3. cfregistry
3. Tags a-b
4. Tags c
  1. cfcache
  2. cfcalendar
  3. cfcase
  4. cfcatch
  5. cfchart
  6. cfchartdata
  7. cfchartseries
  8. cfclient
  9. cfclientsettings
  10. cfcol
  11. cfcollection
  12. cfcomponent
  13. cfcontent
  14. cfcontinue
  15. cfcookie
  16. Tags d-e
5. Tags f
6. Tags g-h
  1. cfgraph
  2. cfgraphdata
  3. cfgrid
  4. cfgridcolumn
  5. cfgridrow
  6. cfgridupdate
  7. cfheader
  8. cfhtmlhead
  9. cfhtmltopdf
  10. cfhtmltopdfitem
  11. cfhttp
  12. cfhttpparam
7. Tags i
  1. cfif
  2. cfimage
  3. cfimap
  4. cfimapfilter
  5. cfimpersonate
  6. cfimport
  7. cfinclude
  8. cfindex
  9. cfinput
  10. cfinsert
  11. cfinterface
  12. cfinvoke
  13. cfinvokeargument
8. Tags j-l
9. Tags m-o
10. Tags p-q
  1. cfparam
  2. cfpdf
  3. cfpdfform
  4. cfpdfformparam
  5. cfpdfparam
  6. cfpdfsubform
  7. cfpod
  8. cfpop
  9. cfpresentation
  10. cfpresentationslide
  11. cfpresenter
  12. cfprint
  13. cfprocessingdirective
  14. cfprocparam
  15. cfprocresult
  16. cfprogressbar
  17. cfproperty
  18. cfquery
  19. cfqueryparam
11. Tags r-s
  1. cfregistry
  2. cfreport
  3. cfreportparam
  4. cfrethrow
  5. cfreturn
  6. cfsavecontent
  7. cfschedule
  8. cfscript
  9. cfsearch
  10. cfselect
  11. cfservlet
  12. cfservletparam
  13. cfset
  14. cfsetting
  15. cfsharepoint
  16. cfsilent
  17. cfslider
  18. cfspreadsheet
  19. cfsprydataset
  20. cfstoredproc
  21. cfswitch
12. Tags t
  1. cftable
  2. cftextarea
  3. cftextinput
  4. cfthread
  5. cfthrow
  6. cftimer
  7. cftooltip
  8. cftrace
  9. cftransaction
  10. cftree
  11. cftreeitem
  12. cftry
13. Tags u-z
  1. cfupdate
  2. cfwddx
  3. cfwebsocket
  4. cfwindow
  5. cfxml
  6. cfzip
  7. cfzipparam
CFML Reference
1. Reserved words and variables
2. Ajax JavaScript functions
3. ColdFusion ActionScript functions
4. ColdFusion mobile functions
5. Application.cfc reference
6. Script functions implemented as CFCs
7. ColdFusion Flash Form style reference
8. ColdFusion event gateway reference
9. ColdFusion C++ CFX Reference
10. ColdFusion Java CFX reference
11. WDDX JavaScript Objects
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Description

Converts the data type of a ColdFusion variable to a specified Java type to pass as an argument to Java or .NET object. Use only for scalar, string, and array arguments.

Returns

The variable, as type type.

Syntax

JavaCast(type, variable)

History

ColdFusion MX 8: Added support for bigdecimal, byte, char, and short data types and for casting Arrays.

ColdFusion MX 7: Added support for nulls.

Parameters

Parameter	Description
type	Data type to which to convert variable: bigdecimal (converts to java.math.BigDecimal) boolean byte char int long float double short string null
variable	A ColdFusion variable that holds a scalar or string type. Must be "" if type is null.

Parameter

Description

type

Data type to which to convert variable:

bigdecimal (converts to java.math.BigDecimal)
boolean
byte
char
int
long
float
double
short
string
null

variable

A ColdFusion variable that holds a scalar or string type. Must be "" if type is null.

Usage

Use this method to specify the Java type to use for a variable that you use when calling a Java or .NET method when the conversion between types is ambiguous; for example, if a method is overloaded and differs only in parameter type or a .NET method is declared as taking a System.Object class parameter.Use after creating a Java object with the cfobject tag, before calling one of its methods. If the method takes more than one overloaded argument, call JavaCast for each one. Use JavaCast only when a method is overloaded (because its arguments can take more than one data type, not because the method can take a variable number of arguments). JavaCast cannot be used to cast between complex objects, nor to cast to a super-class. Because there is not a one-to-one correspondence between internally stored ColdFusion types and Java scalar types, some conversions cannot be performed. Use the result of this function only on calls to Java or .NET objects. The following example shows the use when calling a Java method.

<cfscript> 
x = CreateObject("java", "test.Hello"); 
x.init(); 
ret = x.sayHello(JavaCast("null", "")); 
</cfscript>

Note:

Do not assign the results of JavaCast("null","") to a ColdFusion variable. Unexpected results will occur.

The format JavaCast(type[], variable) casts a ColdFusion Array variable to a single dimensional Array of the specified type. It cannot convert multi-dimensional arrays. You can specify a primitive type or the name of a Class as the type to cast to. For example, you can use the following format to cast a ColdFusion Array to an Array of vom.x.yMyClass objects.

javacast("vom.x.y.MyClass[]", myCFArr)

Use an array in the first JavaCast parameter in any of the following circumstances:

You have two functions with signatures with the same number of parameters, and a parameter takes different types of Arrays in different signatures; for example, if you have both of the following functions: foo(int[] x) and foo(String[] strs).
The method parameter requires a class array in its signature; for example, foo(com.x.y.MyClass[]).
The method parameter requires an Object in its signature and you must pass an array of any particular type.The following example shows the use of the JavaCastfunction to cast arrays:You might have a fooClass class that defines the following two methods, each with two arguments where the first argument differs in the type of the array:

public class fooClass { 
public fooClass () { 
} 
public String foo(long[] arg) { 
return "Argument was a long array"; 
} 
public String foo(int[] arg) { 
return "Argument was an Integer array"; 
} 
}

To be able to use these functions in your CFML, use the JavaCastfunction to convert the ColdFusion Arrray to the array type required by one of the functions, as shown in the following code snippet:

<cfset arr = [1,2,4,20,10]> 
<cfset fooObj = createObject("java", "fooClass")> 

<cfset fooObj.foo(javacasr("int[]", arr))> 
<cfset fooObj.foo(javacast("long[]", arr))>

Example

The method fooMethod in the class fooClass takes one overloaded argument. The fooClass class is defined as follows:

public class fooClass { 
public fooClass () { 
} 
public String fooMethod(String arg) { 
return "Argument was a String"; 
} 
public String fooMethod(int arg) { 
return "Argument was an Integer"; 
}

Within ColdFusion, you use the following code:

<cfobject 
action="create" 
type = "java" 
class = "fooClass" 
name = obj> 

<!--- ColdFusion can treat this as a string or a real number ---> 
<cfset x = 33> 

Perform an explicit cast to an int and call fooMethod:<br> 
<cfset myInt = JavaCast("int", x)> 
<cfoutput>#obj.fooMethod(myInt)#</cfoutput> 
<br><br> 
Perform an explicit cast to a string and call fooMethod:<br> 
<cfset myString = javaCast("String", x)> 
<cfoutput>#obj.fooMethod(myString)#</cfoutput>

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JavaCast

Description

Returns

Category

Syntax

History

See also

Parameters

Usage

Example

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