bsh

Class Reflect

java.lang.Object

bsh.Reflect

public final class Reflect
extends java.lang.Object

All of the reflection API code lies here. It is in the form of static utilities. Maybe this belongs in LHS.java or a generic object wrapper class.

Author:

Pat Niemeyer, Daniel Leuck, Nick nickl- Lombard

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.Object[]	ZERO_ARGS
static java.lang.Class<?>[]	ZERO_TYPES

Constructor Summary

Constructors

Constructor and Description
Reflect()

Method Summary

Modifier and Type	Method and Description
static BshMethod	findMostSpecificBshMethod(java.lang.Class<?>[] idealMatch, java.util.List<BshMethod> methods) Find the best match for signature idealMatch and return the method.
static int	findMostSpecificBshMethodIndex(java.lang.Class<?>[] idealMatch, java.util.List<BshMethod> methods) Find the best match for signature idealMatch and return the position of the matching signature within the list.
static Invocable	findMostSpecificInvocable(java.lang.Class<?>[] idealMatch, java.util.List<Invocable> methods) Find the best match for signature idealMatch and return the method.
static int	findMostSpecificInvocableIndex(java.lang.Class<?>[] idealMatch, java.util.List<Invocable> methods) Find the best match for signature idealMatch and return the position of the matching signature within the list.
static This	getClassInstanceThis(java.lang.Object instance, java.lang.Class<?> genClass) Get the instance bsh namespace field from the object instance.
static Modifiers	getClassModifiers(java.lang.Class<?> type)
static This	getClassStaticThis(java.lang.Class<?> clas, java.lang.String className) Get the static bsh namespace field from the class.
static BshMethod	getDeclaredMethod(java.lang.Class<?> type, java.lang.String name, java.lang.Class<?>[] sig)
static BshMethod[]	getDeclaredMethods(java.lang.Class<?> type)
static Variable	getDeclaredVariable(java.lang.Class<?> type, java.lang.String name)
static Variable[]	getDeclaredVariables(java.lang.Class<?> type)
static java.util.Map.Entry	getEntryForKey(java.lang.Object key, java.util.Map.Entry[] entries)
static BshMethod	getMethod(java.lang.Class<?> type, java.lang.String name, java.lang.Class<?>[] sig)
static BshMethod	getMethod(NameSpace ns, java.lang.String name, java.lang.Class<?>[] sig)
static BshMethod	getMethod(NameSpace ns, java.lang.String name, java.lang.Class<?>[] sig, boolean declaredOnly)
static BshMethod	getMethod(java.lang.Object object, java.lang.String name, java.lang.Class<?>[] sig)
static java.lang.String[]	getMethodNames(NameSpace ns)
static BshMethod[]	getMethods(java.lang.Class<?> type)
static BshMethod[]	getMethods(NameSpace ns)
static BshMethod[]	getMethods(java.lang.Object object)
static java.lang.Object	getNewInstance(java.lang.Class<?> type)
static java.lang.Object	getObjectFieldValue(java.lang.Object object, java.lang.String fieldName) Check for a field with the given name in a java object or scripted object if the field exists fetch the value, if not check for a property value.
static java.lang.Object	getObjectProperty(java.lang.Object obj, java.lang.Object propName)
static java.lang.Object	getObjectProperty(java.lang.Object obj, java.lang.String propName)
static java.lang.Object	getStaticFieldValue(java.lang.Class<?> clas, java.lang.String fieldName)
static NameSpace	getThisNS(java.lang.Class<?> type)
static NameSpace	getThisNS(java.lang.Object object)
static java.lang.Class<?>	getType(java.lang.Object arg) Find the type of an object.
static Variable	getVariable(java.lang.Class<?> type, java.lang.String name)
static Variable	getVariable(NameSpace ns, java.lang.String name)
static Variable	getVariable(java.lang.Object object, java.lang.String name)
static java.lang.String[]	getVariableNames(NameSpace ns)
static Variable[]	getVariables(java.lang.Class<?> type)
static Variable[]	getVariables(NameSpace ns)
static Variable[]	getVariables(NameSpace ns, java.lang.String[] names)
static Variable[]	getVariables(java.lang.Object object)
static boolean	hasModifier(java.lang.String name, int modifiers)
static boolean	hasObjectPropertyGetter(java.lang.Class<?> clas, java.lang.String propName)
static boolean	hasObjectPropertySetter(java.lang.Class<?> clas, java.lang.String propName)
static java.lang.Object	invokeCompiledCommand(java.lang.Class<?> commandClass, java.lang.Object[] args, Interpreter interpreter, CallStack callstack, Node callerInfo) A command may be implemented as a compiled Java class containing one or more static invoke() methods of the correct signature.
static java.lang.Object	invokeObjectMethod(java.lang.Object object, java.lang.String methodName, java.lang.Object[] args, Interpreter interpreter, CallStack callstack, Node callerInfo) Invoke method on arbitrary object instance.
static java.lang.Object	invokeStaticMethod(BshClassManager bcm, java.lang.Class<?> clas, java.lang.String methodName, java.lang.Object[] args, Node callerInfo) Invoke a method known to be static.
static boolean	isGeneratedClass(java.lang.Class<?> type)
static boolean	isPackageAccessible(java.lang.Class<?> clazz)
static boolean	isPackageScope(java.lang.Class<?> clazz)
static boolean	isStatic(java.lang.Class<?> clazz)
static boolean	isStatic(java.lang.reflect.Member member)
protected static Invocable	resolveExpectedJavaField(java.lang.Class<?> clas, java.lang.String fieldName, boolean staticOnly)
protected static Invocable	resolveExpectedJavaMethod(BshClassManager bcm, java.lang.Class<?> clas, java.lang.Object object, java.lang.String name, java.lang.Object[] args, boolean staticOnly) This method wraps resolveJavaMethod() and expects a non-null method result.
protected static Invocable	resolveJavaField(java.lang.Class<?> clas, java.lang.String fieldName, boolean staticOnly)
protected static Invocable	resolveJavaMethod(java.lang.Class<?> clas, java.lang.String name, java.lang.Class<?>[] types, boolean staticOnly) The full blown resolver method.
static java.lang.Object	setObjectProperty(java.lang.Object obj, java.lang.Object propName, java.lang.Object value)
static java.lang.Object	setObjectProperty(java.lang.Object obj, java.lang.String propName, java.lang.Object value)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ZERO_ARGS

public static final java.lang.Object[] ZERO_ARGS

ZERO_TYPES

public static final java.lang.Class<?>[] ZERO_TYPES

Constructor Detail

Reflect

public Reflect()

Method Detail

invokeObjectMethod

public static java.lang.Object invokeObjectMethod(java.lang.Object object,
                                                  java.lang.String methodName,
                                                  java.lang.Object[] args,
                                                  Interpreter interpreter,
                                                  CallStack callstack,
                                                  Node callerInfo)
                                           throws EvalError

Invoke method on arbitrary object instance. May be static (through the object instance) or dynamic. Object may be a bsh scripted object (bsh.This type).

Returns:

the result of the method call

Throws:

EvalError

invokeStaticMethod

public static java.lang.Object invokeStaticMethod(BshClassManager bcm,
                                                  java.lang.Class<?> clas,
                                                  java.lang.String methodName,
                                                  java.lang.Object[] args,
                                                  Node callerInfo)
                                           throws bsh.ReflectError,
                                                  UtilEvalError,
                                                  java.lang.reflect.InvocationTargetException

Invoke a method known to be static. No object instance is needed and there is no possibility of the method being a bsh scripted method.

Throws:

bsh.ReflectError

UtilEvalError

java.lang.reflect.InvocationTargetException

getStaticFieldValue

public static java.lang.Object getStaticFieldValue(java.lang.Class<?> clas,
                                                   java.lang.String fieldName)
                                            throws UtilEvalError,
                                                   bsh.ReflectError

Throws:

UtilEvalError

bsh.ReflectError

getObjectFieldValue

public static java.lang.Object getObjectFieldValue(java.lang.Object object,
                                                   java.lang.String fieldName)
                                            throws UtilEvalError,
                                                   bsh.ReflectError

Check for a field with the given name in a java object or scripted object if the field exists fetch the value, if not check for a property value. If neither is found return Primitive.VOID.

Throws:

UtilEvalError

bsh.ReflectError

resolveJavaField

protected static Invocable resolveJavaField(java.lang.Class<?> clas,
                                            java.lang.String fieldName,
                                            boolean staticOnly)
                                     throws UtilEvalError

Throws:

UtilEvalError

resolveExpectedJavaField

protected static Invocable resolveExpectedJavaField(java.lang.Class<?> clas,
                                                    java.lang.String fieldName,
                                                    boolean staticOnly)
                                             throws UtilEvalError,
                                                    bsh.ReflectError

Throws:

ReflectError - if the field is not found.

UtilEvalError

resolveExpectedJavaMethod

protected static Invocable resolveExpectedJavaMethod(BshClassManager bcm,
                                                     java.lang.Class<?> clas,
                                                     java.lang.Object object,
                                                     java.lang.String name,
                                                     java.lang.Object[] args,
                                                     boolean staticOnly)
                                              throws bsh.ReflectError,
                                                     UtilEvalError

This method wraps resolveJavaMethod() and expects a non-null method result. If the method is not found it throws a descriptive ReflectError.

Throws:

bsh.ReflectError

UtilEvalError

resolveJavaMethod

protected static Invocable resolveJavaMethod(java.lang.Class<?> clas,
                                             java.lang.String name,
                                             java.lang.Class<?>[] types,
                                             boolean staticOnly)
                                      throws UtilEvalError

The full blown resolver method. All other method invocation methods delegate to this. The method may be static or dynamic unless staticOnly is set (in which case object may be null). If staticOnly is set then only static methods will be located.

This method performs caching (caches discovered methods through the class manager and utilizes cached methods.)

This method determines whether to attempt to use non-public methods based on Capabilities.haveAccessibility() and will set the accessibilty flag on the method as necessary.

If, when directed to find a static method, this method locates a more specific matching instance method it will throw a descriptive exception analogous to the error that the Java compiler would produce. Note: as of 2.0.x this is a problem because there is no way to work around this with a cast.

Parameters:

staticOnly - The method located must be static, the object param may be null.

Returns:

the method or null if no matching method was found.

Throws:

UtilEvalError

findMostSpecificBshMethod

public static BshMethod findMostSpecificBshMethod(java.lang.Class<?>[] idealMatch,
                                                  java.util.List<BshMethod> methods)

Find the best match for signature idealMatch and return the method. This method anticipates receiving the full list of BshMethods of the same name, regardless of the potential arity/validity of each method.

Parameters:

idealMatch - the signature to look for

methods - the set of candidate BshMethods which differ only in the types of their arguments.

findMostSpecificBshMethodIndex

public static int findMostSpecificBshMethodIndex(java.lang.Class<?>[] idealMatch,
                                                 java.util.List<BshMethod> methods)

Find the best match for signature idealMatch and return the position of the matching signature within the list. This method anticipates receiving the full list of BshMethods of the same name,regardless of the potential arity/validity of each method. Filter the list of methods for only valid candidates before performing the comparison (e.g. method name and number of args match). Also expand the parameter type list for VarArgs methods.

Parameters:

idealMatch - the signature to look for

methods - the set of candidate BshMethods which differ only in the types of their arguments.

findMostSpecificInvocable

public static Invocable findMostSpecificInvocable(java.lang.Class<?>[] idealMatch,
                                                  java.util.List<Invocable> methods)

Find the best match for signature idealMatch and return the method. This method anticipates receiving the full list of methods of the same name, regardless of the potential arity/validity of each method.

Parameters:

idealMatch - the signature to look for

methods - the set of candidate Invocables which differ only in the types of their arguments.

findMostSpecificInvocableIndex

public static int findMostSpecificInvocableIndex(java.lang.Class<?>[] idealMatch,
                                                 java.util.List<Invocable> methods)

Find the best match for signature idealMatch and return the position of the matching signature within the list. This method anticipates receiving the full list of methods of the same name,regardless of the potential arity/validity of each method. Filter the list of methods for only valid candidates before performing the comparison (e.g. method name and number of args match). Also expand the parameter type list for VarArgs methods. This method currently does not take into account Java 5 covariant return types... which I think will require that we find the most derived return type of otherwise identical best matches.

Parameters:

idealMatch - the signature to look for

methods - the set of candidate method which differ only in the types of their arguments.

hasObjectPropertyGetter

public static boolean hasObjectPropertyGetter(java.lang.Class<?> clas,
                                              java.lang.String propName)

hasObjectPropertySetter

public static boolean hasObjectPropertySetter(java.lang.Class<?> clas,
                                              java.lang.String propName)

getObjectProperty

public static java.lang.Object getObjectProperty(java.lang.Object obj,
                                                 java.lang.String propName)

getObjectProperty

public static java.lang.Object getObjectProperty(java.lang.Object obj,
                                                 java.lang.Object propName)

getEntryForKey

public static java.util.Map.Entry getEntryForKey(java.lang.Object key,
                                                 java.util.Map.Entry[] entries)

setObjectProperty

public static java.lang.Object setObjectProperty(java.lang.Object obj,
                                                 java.lang.String propName,
                                                 java.lang.Object value)

setObjectProperty

public static java.lang.Object setObjectProperty(java.lang.Object obj,
                                                 java.lang.Object propName,
                                                 java.lang.Object value)

invokeCompiledCommand

public static java.lang.Object invokeCompiledCommand(java.lang.Class<?> commandClass,
                                                     java.lang.Object[] args,
                                                     Interpreter interpreter,
                                                     CallStack callstack,
                                                     Node callerInfo)
                                              throws UtilEvalError

A command may be implemented as a compiled Java class containing one or more static invoke() methods of the correct signature. The invoke() methods must accept two additional leading arguments of the interpreter and callstack, respectively. e.g. invoke(interpreter, callstack, ... ) This method adds the arguments and invokes the static method, returning the result.

Throws:

UtilEvalError

isGeneratedClass

public static boolean isGeneratedClass(java.lang.Class<?> type)

getClassStaticThis

public static This getClassStaticThis(java.lang.Class<?> clas,
                                      java.lang.String className)

Get the static bsh namespace field from the class.

Parameters:

className - may be the name of clas itself or a superclass of clas.

getClassInstanceThis

public static This getClassInstanceThis(java.lang.Object instance,
                                        java.lang.Class<?> genClass)

Get the instance bsh namespace field from the object instance.

Returns:

the class instance This object or null if the object has not been initialized.

getThisNS

public static NameSpace getThisNS(java.lang.Class<?> type)

getThisNS

public static NameSpace getThisNS(java.lang.Object object)

getVariableNames

public static java.lang.String[] getVariableNames(NameSpace ns)

getMethodNames

public static java.lang.String[] getMethodNames(NameSpace ns)

getMethod

public static BshMethod getMethod(java.lang.Class<?> type,
                                  java.lang.String name,
                                  java.lang.Class<?>[] sig)

getMethod

public static BshMethod getMethod(java.lang.Object object,
                                  java.lang.String name,
                                  java.lang.Class<?>[] sig)

getMethod

public static BshMethod getMethod(NameSpace ns,
                                  java.lang.String name,
                                  java.lang.Class<?>[] sig)

getMethod

public static BshMethod getMethod(NameSpace ns,
                                  java.lang.String name,
                                  java.lang.Class<?>[] sig,
                                  boolean declaredOnly)

getDeclaredMethod

public static BshMethod getDeclaredMethod(java.lang.Class<?> type,
                                          java.lang.String name,
                                          java.lang.Class<?>[] sig)

getMethods

public static BshMethod[] getMethods(java.lang.Class<?> type)

getMethods

public static BshMethod[] getMethods(java.lang.Object object)

getMethods

public static BshMethod[] getMethods(NameSpace ns)

getDeclaredMethods

public static BshMethod[] getDeclaredMethods(java.lang.Class<?> type)

getVariable

public static Variable getVariable(java.lang.Class<?> type,
                                   java.lang.String name)

getVariable

public static Variable getVariable(java.lang.Object object,
                                   java.lang.String name)

getVariable

public static Variable getVariable(NameSpace ns,
                                   java.lang.String name)

getDeclaredVariable

public static Variable getDeclaredVariable(java.lang.Class<?> type,
                                           java.lang.String name)

getVariables

public static Variable[] getVariables(java.lang.Class<?> type)

getVariables

public static Variable[] getVariables(java.lang.Object object)

getVariables

public static Variable[] getVariables(NameSpace ns)

getVariables

public static Variable[] getVariables(NameSpace ns,
                                      java.lang.String[] names)

getDeclaredVariables

public static Variable[] getDeclaredVariables(java.lang.Class<?> type)

getClassModifiers

public static Modifiers getClassModifiers(java.lang.Class<?> type)

getNewInstance

public static java.lang.Object getNewInstance(java.lang.Class<?> type)

isStatic

public static boolean isStatic(java.lang.reflect.Member member)

isStatic

public static boolean isStatic(java.lang.Class<?> clazz)

hasModifier

public static boolean hasModifier(java.lang.String name,
                                  int modifiers)

isPackageScope

public static boolean isPackageScope(java.lang.Class<?> clazz)

isPackageAccessible

public static boolean isPackageAccessible(java.lang.Class<?> clazz)

getType

public static java.lang.Class<?> getType(java.lang.Object arg)

Find the type of an object.