org.picocontainer.parameters.ConstantParameter Maven / Gradle / Ivy
/*****************************************************************************
* Copyright (c) PicoContainer Organization. All rights reserved. *
* ------------------------------------------------------------------------- *
* The software in this package is published under the terms of the BSD *
* style license a copy of which has been included with this distribution in *
* the LICENSE.txt file. *
* *
* Idea by Rachel Davies, Original code by Jon Tirsen *
*****************************************************************************/
package org.picocontainer.parameters;
import org.picocontainer.ComponentAdapter;
import org.picocontainer.Parameter;
import org.picocontainer.PicoContainer;
import org.picocontainer.PicoException;
import org.picocontainer.PicoCompositionException;
import org.picocontainer.PicoVisitor;
import org.picocontainer.NameBinding;
import java.io.Serializable;
import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.annotation.Annotation;
/**
* A ConstantParameter should be used to pass in "constant" arguments to constructors. This
* includes {@link String}s,{@link Integer}s or any other object that is not registered in
* the container.
*
* @author Jon Tirsén
* @author Aslak Hellesøy
* @author Jörg Schaible
* @author Thomas Heller
*/
@SuppressWarnings("serial")
public class ConstantParameter extends AbstractParameter implements Parameter, Serializable {
private final Object value;
public ConstantParameter(Object value) {
this.value = value;
}
public Resolver resolve(PicoContainer container, ComponentAdapter> forAdapter,
ComponentAdapter> injecteeAdapter, final Type expectedType, NameBinding expectedNameBinding,
boolean useNames, Annotation binding) {
if (expectedType instanceof Class) {
return new Parameter.ValueResolver(isAssignable((Class) expectedType), value, null);
} else if (expectedType instanceof ParameterizedType) {
return new Parameter.ValueResolver(isAssignable(((ParameterizedType)expectedType).getRawType()), value, null);
}
return new Parameter.ValueResolver(true, value, null);
}
/**
* {@inheritDoc}
*
* @see Parameter#verify(org.picocontainer.PicoContainer,org.picocontainer.ComponentAdapter,java.lang.reflect.Type,org.picocontainer.NameBinding,boolean,java.lang.annotation.Annotation)
*/
public void verify(PicoContainer container, ComponentAdapter> adapter,
Type expectedType, NameBinding expectedNameBinding,
boolean useNames, Annotation binding) throws PicoException {
if (!isAssignable(expectedType)) {
throw new PicoCompositionException(
expectedType + " is not assignable from " +
(value != null ? value.getClass().getName() : "null"));
}
}
protected boolean isAssignable(Type expectedType) {
boolean isAssignable;
if (expectedType instanceof Class) {
Class expectedClass = (Class) expectedType;
if (checkPrimitive(expectedClass) || expectedClass.isInstance(value)) {
return true;
}
}
return false;
}
/**
* Visit the current {@link Parameter}.
*
* @see org.picocontainer.Parameter#accept(org.picocontainer.PicoVisitor)
*/
public void accept(final PicoVisitor visitor) {
visitor.visitParameter(this);
}
private boolean checkPrimitive(Class expectedType) {
try {
if (expectedType.isPrimitive()) {
final Field field = value.getClass().getField("TYPE");
final Class type = (Class) field.get(value);
return expectedType.isAssignableFrom(type);
}
} catch (NoSuchFieldException e) {
//ignore
} catch (IllegalAccessException e) {
//ignore
}
return false;
}
}