org.picocontainer.injectors.AbstractInjector 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. *
* *
* Original code by *
*****************************************************************************/
package org.picocontainer.injectors;
import org.picocontainer.ComponentAdapter;
import org.picocontainer.ComponentMonitor;
import org.picocontainer.ObjectReference;
import org.picocontainer.Parameter;
import org.picocontainer.PicoCompositionException;
import org.picocontainer.PicoContainer;
import org.picocontainer.PicoVisitor;
import org.picocontainer.adapters.AbstractAdapter;
import org.picocontainer.parameters.ComponentParameter;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Member;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;
/**
* This ComponentAdapter will instantiate a new object for each call to
* {@link org.picocontainer.ComponentAdapter#getComponentInstance(PicoContainer, Type)}.
* That means that when used with a PicoContainer, getComponent will
* return a new object each time.
*
* @author Aslak Hellesøy
* @author Paul Hammant
* @author Jörg Schaible
* @author Mauro Talevi
*/
@SuppressWarnings("serial")
public abstract class AbstractInjector extends AbstractAdapter implements org.picocontainer.Injector {
/** The cycle guard for the verification. */
protected transient ThreadLocalCyclicDependencyGuard verifyingGuard;
/** The parameters to use for initialization. */
protected transient Parameter[] parameters;
/** The strategy used to control the lifecycle */
private final boolean useNames;
/**
* Constructs a new ComponentAdapter for the given key and implementation.
* @param componentKey the search key for this implementation
* @param componentImplementation the concrete implementation
* @param parameters the parameters to use for the initialization
* @param monitor the component monitor used by this ComponentAdapter
* @throws org.picocontainer.injectors.AbstractInjector.NotConcreteRegistrationException if the implementation is not a concrete class
* @throws NullPointerException if one of the parameters is null
*/
protected AbstractInjector(final Object componentKey, final Class componentImplementation, final Parameter[] parameters,
final ComponentMonitor monitor, final boolean useNames) {
super(componentKey, componentImplementation, monitor);
this.useNames = useNames;
checkConcrete();
if (parameters != null) {
for (int i = 0; i < parameters.length; i++) {
if(parameters[i] == null) {
throw new NullPointerException("Parameter " + i + " is null");
}
}
}
this.parameters = parameters;
}
public boolean useNames() {
return useNames;
}
private void checkConcrete() throws NotConcreteRegistrationException {
// Assert that the component class is concrete.
boolean isAbstract = (getComponentImplementation().getModifiers() & Modifier.ABSTRACT) == Modifier.ABSTRACT;
if (getComponentImplementation().isInterface() || isAbstract) {
throw new NotConcreteRegistrationException(getComponentImplementation());
}
}
/**
* Create default parameters for the given types.
*
* @param length parameter list length
* @return the array with the default parameters.
*/
protected Parameter[] createDefaultParameters(int length) {
Parameter[] componentParameters = new Parameter[length];
for (int i = 0; i < length; i++) {
componentParameters[i] = ComponentParameter.DEFAULT;
}
return componentParameters;
}
@SuppressWarnings("unused")
public void verify(PicoContainer container) throws PicoCompositionException {
}
@Override
public T getComponentInstance(PicoContainer container) throws PicoCompositionException {
return getComponentInstance(container, NOTHING.class);
}
public abstract T getComponentInstance(PicoContainer container, Type into) throws PicoCompositionException;
@SuppressWarnings("unused")
public Object decorateComponentInstance(PicoContainer container, Type into, T instance) {
return null;
}
@Override
public void accept(final PicoVisitor visitor) {
super.accept(visitor);
if (parameters != null) {
for (Parameter parameter : parameters) {
parameter.accept(visitor);
}
}
}
public String getDescriptor() {
return "Asbtract Injector";
}
/**
* Instantiate an object with given parameters and respect the accessible flag.
*
* @param constructor the constructor to use
* @param parameters the parameters for the constructor
* @return the new object.
* @throws InstantiationException
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
protected T newInstance(final Constructor constructor, final Object[] parameters)
throws InstantiationException, IllegalAccessException, InvocationTargetException {
return constructor.newInstance(parameters);
}
/**
* inform monitor about component instantiation failure
* @param componentMonitor
* @param constructor
* @param e
* @param container
* @return
*/
protected T caughtInstantiationException(final ComponentMonitor componentMonitor,
final Constructor constructor,
final InstantiationException e, final PicoContainer container) {
// can't get here because checkConcrete() will catch it earlier, but see PICO-191
componentMonitor.instantiationFailed(container, this, constructor, e);
throw new PicoCompositionException("Should never get here");
}
/**
* inform monitor about access exception.
* @param componentMonitor
* @param constructor
* @param e
* @param container
* @return
*/
protected T caughtIllegalAccessException(final ComponentMonitor componentMonitor,
final Constructor constructor,
final IllegalAccessException e, final PicoContainer container) {
// can't get here because either filtered or access mode set
componentMonitor.instantiationFailed(container, this, constructor, e);
throw new PicoCompositionException(e);
}
/**
* inform monitor about exception while instantiating component
* @param componentMonitor
* @param member
* @param componentInstance
* @param e
* @return
*/
protected T caughtInvocationTargetException(final ComponentMonitor componentMonitor,
final Member member,
final Object componentInstance, final InvocationTargetException e) {
componentMonitor.invocationFailed(member, componentInstance, e);
if (e.getTargetException() instanceof RuntimeException) {
throw (RuntimeException) e.getTargetException();
} else if (e.getTargetException() instanceof Error) {
throw (Error) e.getTargetException();
}
throw new PicoCompositionException(e.getTargetException());
}
protected Object caughtIllegalAccessException(final ComponentMonitor componentMonitor,
final Member member,
final Object componentInstance, final IllegalAccessException e) {
componentMonitor.invocationFailed(member, componentInstance, e);
throw new PicoCompositionException(e);
}
protected Type box(Type parameterType) {
if (parameterType instanceof Class && ((Class) parameterType).isPrimitive()) {
String parameterTypeName = ((Class) parameterType).getName();
if (parameterTypeName == "int") {
return Integer.class;
} else if (parameterTypeName == "boolean") {
return Boolean.class;
} else if (parameterTypeName == "long") {
return Long.class;
} else if (parameterTypeName == "float") {
return Float.class;
} else if (parameterTypeName == "double") {
return Double.class;
} else if (parameterTypeName == "char") {
return Character.class;
} else if (parameterTypeName == "byte") {
return Byte.class;
} else if (parameterTypeName == "short") {
return Short.class;
}
}
return parameterType;
}
/**
* Abstract utility class to detect recursion cycles.
* Derive from this class and implement {@link ThreadLocalCyclicDependencyGuard#run}.
* The method will be called by {@link ThreadLocalCyclicDependencyGuard#observe}. Select
* an appropriate guard for your scope. Any {@link ObjectReference} can be
* used as long as it is initialized with Boolean.FALSE.
*
* @author Jörg Schaible
*/
static abstract class ThreadLocalCyclicDependencyGuard extends ThreadLocal {
protected PicoContainer guardedContainer;
/**
* Derive from this class and implement this function with the functionality
* to observe for a dependency cycle.
*
* @return a value, if the functionality result in an expression,
* otherwise just return null
* @param instance
*/
public abstract T run(Object instance);
/**
* Call the observing function. The provided guard will hold the {@link Boolean} value.
* If the guard is already Boolean.TRUE a {@link CyclicDependencyException}
* will be thrown.
*
*
* @param stackFrame the current stack frame
* @param instance
* @return the result of the run method
*/
public final T observe(final Class stackFrame, final Object instance) {
if (Boolean.TRUE.equals(get())) {
throw new CyclicDependencyException(stackFrame);
}
T result = null;
try {
set(Boolean.TRUE);
result = run(instance);
} catch (final CyclicDependencyException e) {
e.push(stackFrame);
throw e;
} finally {
set(null);
}
return result;
}
public void setGuardedContainer(final PicoContainer container) {
this.guardedContainer = container;
}
}
public static class CyclicDependencyException extends PicoCompositionException {
private final List stack;
/**
* @param element
*/
public CyclicDependencyException(final Class element) {
super((Throwable)null);
this.stack = new LinkedList();
push(element);
}
/**
* @param element
*/
public void push(final Class element) {
stack.add(element);
}
public Class[] getDependencies() {
return stack.toArray(new Class[stack.size()]);
}
@Override
public String getMessage() {
return "Cyclic dependency: " + stack.toString();
}
}
/**
* Exception that is thrown as part of the introspection. Raised if a PicoContainer cannot resolve a
* type dependency because the registered {@link org.picocontainer.ComponentAdapter}s are not
* distinct.
*
* @author Paul Hammant
* @author Aslak Hellesøy
* @author Jon Tirsén
*/
public static final class AmbiguousComponentResolutionException extends PicoCompositionException {
private Class component;
private final Class ambiguousDependency;
private final Object[] ambiguousComponentKeys;
private AccessibleObject accessibleObject;
/**
* Construct a new exception with the ambiguous class type and the ambiguous component keys.
*
* @param ambiguousDependency the unresolved dependency type
* @param componentKeys the ambiguous keys.
*/
public AmbiguousComponentResolutionException(final Class ambiguousDependency, final Object[] componentKeys) {
super("");
this.ambiguousDependency = ambiguousDependency;
this.ambiguousComponentKeys = new Class[componentKeys.length];
System.arraycopy(componentKeys, 0, ambiguousComponentKeys, 0, componentKeys.length);
}
/**
* @return Returns a string containing the unresolved class type and the ambiguous keys.
*/
@Override
public String getMessage() {
StringBuffer msg = new StringBuffer();
msg.append(component != null ? component : "");
msg.append(" needs a '");
msg.append(ambiguousDependency.getName());
msg.append("' injected via '");
msg.append(accessibleObject != null ? accessibleObject : "");
msg.append("', but there are too many choices to inject. These:");
msg.append(Arrays.asList(getAmbiguousComponentKeys()));
msg.append(", refer http://picocontainer.org/ambiguous-injectable-help.html");
return msg.toString();
}
/**
* @return Returns the ambiguous component keys as array.
*/
public Object[] getAmbiguousComponentKeys() {
return ambiguousComponentKeys;
}
public void setComponent(final Class component) {
this.component = component;
}
public void setMember(AccessibleObject accessibleObject) {
this.accessibleObject = accessibleObject;
}
}
/**
* Exception thrown when some of the component's dependencies are not satisfiable.
*
* @author Aslak Hellesøy
* @author Mauro Talevi
*/
public static class UnsatisfiableDependenciesException extends PicoCompositionException {
public UnsatisfiableDependenciesException(String message) {
super(message);
}
}
/**
* @author Aslak Hellesoy
*/
public static class NotConcreteRegistrationException extends PicoCompositionException {
private final Class componentImplementation;
public NotConcreteRegistrationException(final Class componentImplementation) {
super("Bad Access: '" + componentImplementation.getName() + "' is not instantiable");
this.componentImplementation = componentImplementation;
}
public Class getComponentImplementation() {
return componentImplementation;
}
}
}
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