Interface IClassBodyEvaluator
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- All Superinterfaces:
ICookable
- All Known Subinterfaces:
IExpressionEvaluator
,IScriptEvaluator
- All Known Implementing Classes:
ClassBodyEvaluator
,ClassBodyEvaluator
,ExpressionEvaluator
,ExpressionEvaluator
,ScriptEvaluator
,ScriptEvaluator
public interface IClassBodyEvaluator extends ICookable
Parses a class body and returns it as aClass
object ready for use with java.lang.reflect.Example:
import java.util.*; static private int a = 1; private int b = 2; public void func(int c, int d) { return func2(c, d); } private static void func2(int e, int f) { return e * f; }
To set up an
IClassBodyEvaluator
object, proceed as follows:-
Create an
IClassBodyEvaluator
-implementing class. -
Configure the
IClassBodyEvaluator
by calling any of the following methods: -
Call any of the
ICookable.cook(String, java.io.Reader)
methods to scan, parse, compile and load the class body into the JVM.
createInstance(Reader)
methods can be used.The generated class may optionally extend/implement a given type; the returned instance can safely be type-casted to that
optionalBaseType
.Example:
public interface Foo { int bar(int a, int b); } ...
IClassBodyEvaluator
cbe =CompilerFactoryFactory
.getDefaultCompilerFactory
().newClassBodyEvaluator
(); Foo f = (Foo) ClassBodyEvaluator.createFastClassBodyEvaluator( new Scanner(null, new StringReader("public int bar(int a, int b) { return a + b; }")), Foo.class, // Base type to extend/implement (ClassLoader) null // Use current thread's context class loader ); System.out.println("1 + 2 = " + f.bar(1, 2));
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Field Summary
Fields Modifier and Type Field Description static String
DEFAULT_CLASS_NAME
Default name for the generated class.-
Fields inherited from interface org.codehaus.commons.compiler.ICookable
BOOT_CLASS_LOADER, SYSTEM_PROPERTY_SOURCE_DEBUGGING_DIR, SYSTEM_PROPERTY_SOURCE_DEBUGGING_ENABLE
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Method Summary
All Methods Instance Methods Abstract Methods Deprecated Methods Modifier and Type Method Description Object
createInstance(Reader reader)
Scans, parses and compiles a class body from the tokens delivered by the the givenReader
, then creates and returns an instance of that class.Class
getClazz()
Returns the loadedClass
.void
setClassName(String className)
Set the name of the generated class.void
setDefaultImports(String[] optionalDefaultImports)
"Default imports" add to the system import "java.lang", i.e.void
setExtendedClass(Class optionalExtendedClass)
Set a particular superclass that the generated class will extend.void
setExtendedType(Class optionalExtendedClass)
Deprecated.UsesetExtendedClass(Class)
instead.void
setImplementedInterfaces(Class[] implementedInterfaces)
Set a particular set of interfaces that the generated class will implement.void
setImplementedTypes(Class[] implementedInterfaces)
Deprecated.UsesetImplementedInterfaces(Class[])
instead.-
Methods inherited from interface org.codehaus.commons.compiler.ICookable
cook, cook, cook, cook, cook, cook, cook, cook, cookFile, cookFile, cookFile, cookFile, setCompileErrorHandler, setDebuggingInformation, setParentClassLoader, setWarningHandler
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Field Detail
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DEFAULT_CLASS_NAME
static final String DEFAULT_CLASS_NAME
Default name for the generated class.- See Also:
- Constant Field Values
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Method Detail
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setDefaultImports
void setDefaultImports(String[] optionalDefaultImports)
"Default imports" add to the system import "java.lang", i.e. the evaluator may refer to classes imported by default imports without having to explicitly declare IMPORT statements.Notice that JDK 5 "static imports" are also supported, as shown in the following example.
Example:
sc.setDefaultImports(new String[] { "java.util.Map", // Single type import "java.io.*", // Type-import-on-demand "static java.util.Collections.EMPTY_MAP", // Single static import "static java.util.Collections.*", // Static-import-on-demand });
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setClassName
void setClassName(String className)
Set the name of the generated class. Defaults toDEFAULT_CLASS_NAME
. In most cases, there is no need to set this name, because the generated class is loaded into its ownClassLoader
where its name cannot collide with classes generated by other evaluators.One reason to use this function is to have a class name in a non-default package, which can be relevant when types and members with DEFAULT accessibility are accessed.
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setExtendedClass
void setExtendedClass(Class optionalExtendedClass)
Set a particular superclass that the generated class will extend. Ifnull
is passed, the generated class will extendObject
.The common reason to set a base class for an evaluator is that the generated class can directly access the base superclass's (non-private) members.
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setExtendedType
@Deprecated void setExtendedType(Class optionalExtendedClass)
Deprecated.UsesetExtendedClass(Class)
instead.
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setImplementedInterfaces
void setImplementedInterfaces(Class[] implementedInterfaces)
Set a particular set of interfaces that the generated class will implement.
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setImplementedTypes
@Deprecated void setImplementedTypes(Class[] implementedInterfaces)
Deprecated.UsesetImplementedInterfaces(Class[])
instead.
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getClazz
Class getClazz()
Returns the loadedClass
.This method must only be called after exactly one of the
ICookable.cook(String, java.io.Reader)
methods was called.
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createInstance
Object createInstance(Reader reader) throws CompileException, IOException
Scans, parses and compiles a class body from the tokens delivered by the the givenReader
, then creates and returns an instance of that class.- Parameters:
reader
- Source of class body tokens- Returns:
- An object that extends the
optionalExtendedType
and implements the givenimplementedTypes
- Throws:
CompileException
IOException
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