net.sf.jguiraffe.di.impl

Class MethodInvocation

java.lang.Object

net.sf.jguiraffe.di.impl.Invocation

net.sf.jguiraffe.di.impl.MethodInvocation

All Implemented Interfaces:

Invokable

public class MethodInvocation
extends Invocation
implements Invokable

A class that represents a method invocation.

This class stores all data, which is needed for invoking a method; i.e. the method name, the target class, optional information about the data types of the method parameters, and the current parameter values to be passed to the method.

Once initialized, an instance is immutable. So it can easily be shared between multiple components and threads without having to care about synchronization issues. The invoke() method actually executes the corresponding method.

Version:

$Id: MethodInvocation.java 207 2012-02-09 07:30:13Z oheger $

Author:

Oliver Heger

Constructor Summary

Constructors

Constructor and Description
MethodInvocation(ClassDescription targetClass, Dependency targetDep, String methodName, boolean isStatic, ClassDescription[] paramTypes, Dependency... paramValues) Creates a new instance of MethodInvocation and fully initializes it.
MethodInvocation(ClassDescription targetClass, String methodName, boolean isStatic, ClassDescription[] paramTypes, Dependency... paramValues) Creates a new instance of MethodInvocation and initializes most of the properties.
MethodInvocation(ClassDescription targetClass, String methodName, ClassDescription[] paramTypes, Dependency... paramValues) Creates a new instance of MethodInvocation and initializes it with information about the method to invoke and the target class.
MethodInvocation(String methodName, ClassDescription[] paramTypes, Dependency... paramValues) Creates a new instance of MethodInvocation for non-static method invocations.

Method Summary

Modifier and Type	Method and Description
String	getMethodName() Returns the name of the method to be invoked.
List<Dependency>	getParameterDependencies() Returns the Dependency objects defining the current parameter values.
Dependency	getTargetDependency() Returns the target Dependency of this MethodInvocation.
protected void	invocationInfoToString(StringBuilder buf) Creates a string with additional information about this invocation.
Object	invoke(DependencyProvider depProvider, Object target) Invokes the corresponding method on the specified target instance.
boolean	isStaticInvocation() Returns the static flag.

Methods inherited from class net.sf.jguiraffe.di.impl.Invocation

checkDependencyProvider, getParameterClasses, getParameterTypes, getResolvedParameters, getTargetClass, isTypeInfoComplete, parametersToString, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

MethodInvocation

public MethodInvocation(String methodName,
                        ClassDescription[] paramTypes,
                        Dependency... paramValues)

Creates a new instance of MethodInvocation for non-static method invocations. This constructor sets the target class to null, so that it can only be derived from the target instance (which prohibits static method invocations).

Parameters:

methodName - the name of the method to be invoked (must not be null)

paramTypes - an array with the parameter types

paramValues - the current parameter values (defined as Dependency objects); this array must not contain null elements

Throws:

IllegalArgumentException - if the length of the parameter types array does not match the length of the parameter values array, or if the values array contains null elements, or if the method name is undefined

MethodInvocation

public MethodInvocation(ClassDescription targetClass,
                        String methodName,
                        ClassDescription[] paramTypes,
                        Dependency... paramValues)

Creates a new instance of MethodInvocation and initializes it with information about the method to invoke and the target class.

Parameters:

targetClass - the class, on which the method is to be invoked

methodName - the name of the method to be invoked (must not be null)

paramTypes - an array with the parameter types

paramValues - the current parameter values (defined as Dependency objects); this array must not contain null elements

Throws:

IllegalArgumentException - if the length of the parameter types array does not match the length of the parameter values array, or if the values array contains null elements, or if the method name is undefined

See Also:

Invocation#Invocation(Class, Class[], Dependency...)

MethodInvocation

public MethodInvocation(ClassDescription targetClass,
                        String methodName,
                        boolean isStatic,
                        ClassDescription[] paramTypes,
                        Dependency... paramValues)

Creates a new instance of MethodInvocation and initializes most of the properties. This constructor is appropriate for static or non-static invocations which are performed on the target object passed to the invoke() method.

Parameters:

targetClass - the class, on which the method is to be invoked

methodName - the name of the method to be invoked (must not be null)

isStatic - determines whether a static method is to be invoked

paramTypes - an array with the parameter types

paramValues - the current parameter values (defined as Dependency objects); this array must not contain null elements

Throws:

IllegalArgumentException - if the length of the parameter types array does not match the length of the parameter values array, or if the values array contains null elements, or if the method name is undefined, or if the static flag is true, but no target class is defined

See Also:

Invocation#Invocation(Class, Class[], Dependency...)

MethodInvocation

public MethodInvocation(ClassDescription targetClass,
                        Dependency targetDep,
                        String methodName,
                        boolean isStatic,
                        ClassDescription[] paramTypes,
                        Dependency... paramValues)

Creates a new instance of MethodInvocation and fully initializes it. This constructor takes all information required for arbitrary method invocations. It is especially possible to define a dependency for the target object. If set, this dependency is resolved during invocation; a target object is then ignored. Refer to the base class for a detailed explanation of the arguments.

Parameters:

targetClass - the class, on which the method is to be invoked

targetDep - an optional Dependency to the target bean on which the method should be invoked

methodName - the name of the method to be invoked (must not be null)

isStatic - determines whether a static method is to be invoked

paramTypes - an array with the parameter types

paramValues - the current parameter values (defined as Dependency objects); this array must not contain null elements

Throws:

IllegalArgumentException - if the length of the parameter types array does not match the length of the parameter values array, or if the values array contains null elements, or if the method name is undefined, or if the static flag is true, but no target class is defined

Since:

1.1

See Also:

Invocation#Invocation(Class, Class[], Dependency...)

Method Detail

getMethodName

public String getMethodName()

Returns the name of the method to be invoked.

Returns:

the method name

isStaticInvocation

public boolean isStaticInvocation()

Returns the static flag. This flag indicates whether a static method is to be invoked.

Returns:

the static invocation flag

getTargetDependency

public Dependency getTargetDependency()

Returns the target Dependency of this MethodInvocation. This dependency defines the bean on which the method is to be invoked. If there is no target dependency, result is null.

Returns:

the target Dependency

Since:

1.1

getParameterDependencies

public List<Dependency> getParameterDependencies()

Returns the Dependency objects defining the current parameter values. This implementation adds the dependency to the invocation target if it exists.

Specified by:

getParameterDependencies in interface Invokable

Overrides:

getParameterDependencies in class Invocation

Returns:

a list with the Dependency objects for the parameter values

invoke

public Object invoke(DependencyProvider depProvider,
                     Object target)

Invokes the corresponding method on the specified target instance. The method's result is returned. The behavior of this method depends on the isStaticInvocation() flag. If it is set, a passed in target object is ignored and a static method invocation on the target class is performed. Otherwise, if a non null target object is passed in, the target class is derived from this instance (an eventually set target class is ignored).

Specified by:

invoke in interface Invokable

Parameters:

depProvider - the dependency provider for resolving the parameters (must not be null)

target - the target instance, on which to invoke the method

Returns:

the method's return value

Throws:

InjectionException - in case of an error

IllegalArgumentException - if the dependency provider is null

invocationInfoToString

protected void invocationInfoToString(StringBuilder buf)

Creates a string with additional information about this invocation. This implementation will output the method name.

Overrides:

invocationInfoToString in class Invocation

Parameters:

buf - the target buffer