//========================================================================//$Id: Injection.java 4027 2008-11-12 00:59:06Z janb $//Copyright 2006 Mort Bay Consulting Pty. Ltd.//------------------------------------------------------------------------//Licensed under the Apache License, Version 2.0 (the "License");//you may not use this file except in compliance with the License.//You may obtain a copy of the License at //http://www.apache.org/licenses/LICENSE-2.0//Unless required by applicable law or agreed to in writing, software//distributed under the License is distributed on an "AS IS" BASIS,//WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.//See the License for the specific language governing permissions and//limitations under the License.//========================================================================package org.mortbay.jetty.plus.annotation;import java.lang.reflect.Field;import java.lang.reflect.Member;import java.lang.reflect.Method;import javax.naming.InitialContext;import javax.naming.NamingException;import org.mortbay.log.Log;import org.mortbay.util.IntrospectionUtil;/** * Injection * * Represents the injection of a resource into a target (method or field). * The injection is performed by doing an ENC lookup using the jndi * name provided, and setting the object obtained on the target. * */public class Injection{    private Class _targetClass;    private String _jndiName;    private String _mappingName;    private Member _target;            public Injection ()    {}        /**     * @return the _className     */    public Class getTargetClass()    {        return _targetClass;    }    /**     * @param name the _className to set     */    public void setTargetClass(Class clazz)    {        _targetClass = clazz;    }        /**     * @return the jndiName     */    public String getJndiName()    {        return _jndiName;    }    /**     * @param jndiName the jndiName to set     */    public void setJndiName(String jndiName)    {        this._jndiName = jndiName;    }    /**     * @return the mappingName     */    public String getMappingName()    {        return _mappingName;    }    /**     * @param mappingName the mappingName to set     */    public void setMappingName(String mappingName)    {        this._mappingName = mappingName;    }        /**     * @return the target     */    public Member getTarget()    {        return _target;    }        /**     * @param target the target to set     */    public void setTarget(Member target)    {        this._target = target;    }    //TODO: define an equals method        public void setTarget (Class clazz, String targetName, Class targetType)    {        //first look for a javabeans style setter matching the targetName        String setter = "set"+targetName.substring(0,1).toUpperCase()+targetName.substring(1);        try        {            Log.debug("Looking for method for setter: "+setter+" with arg "+targetType);            _target = IntrospectionUtil.findMethod(clazz, setter, new Class[] {targetType}, true, false);             _targetClass = clazz;        }        catch (NoSuchMethodException me)        {            //try as a field            try            {                _target = IntrospectionUtil.findField(clazz, targetName, targetType, true, false);                _targetClass = clazz;            }            catch (NoSuchFieldException fe)            {                throw new IllegalArgumentException("No such field or method "+targetName+" on class "+_targetClass);            }        }    }        /**     * Inject a value for a Resource from JNDI into an object     * @param injectable     * @throws Exception     */    public void inject (Object injectable)    {        Member theTarget = getTarget();         if (theTarget instanceof Field)        {            injectField((Field)theTarget, injectable);        }        else if (theTarget instanceof Method)        {            injectMethod((Method)theTarget, injectable);        }    }        /**     * The Resource must already exist in the ENC of this webapp.     * @return     * @throws Exception     */    public Object lookupInjectedValue ()    throws NamingException    {        InitialContext context = new InitialContext();        return context.lookup("java:comp/env/"+getJndiName());    }            /**     * Inject value from jndi into a field of an instance     * @param field     * @param injectable     */    public void injectField (Field field, Object injectable)    {                   try        {            //validateInjection(field, injectable);            boolean accessibility = field.isAccessible();            field.setAccessible(true);            field.set(injectable, lookupInjectedValue());            field.setAccessible(accessibility);        }        catch (Exception e)        {            Log.warn(e);            throw new IllegalStateException("Inject failed for field "+field.getName());        }    }        /**     * Inject value from jndi into a setter method of an instance     * @param method     * @param injectable     */    public void injectMethod (Method method, Object injectable)    {        //validateInjection(method, injectable);        try        {            boolean accessibility = method.isAccessible();            method.setAccessible(true);            method.invoke(injectable, new Object[] {lookupInjectedValue()});            method.setAccessible(accessibility);        }        catch (Exception e)        {            Log.warn(e);            throw new IllegalStateException("Inject failed for method "+method.getName());        }    }              private void validateInjection (Method method, Object injectable)    throws NoSuchMethodException    {        if ((injectable==null) || (method==null))            return;        //check the injection target actually has a matching method        //TODO: think about this, they have to be assignable        injectable.getClass().getMethod(method.getName(), method.getParameterTypes());        }        private void validateInjection (Field field, Object injectable)     throws NoSuchFieldException    {        if ((field==null) || (injectable==null))            return;        Field f = injectable.getClass().getField(field.getName());        if (!f.getType().isAssignableFrom(field.getType()))            throw new NoSuchFieldException("Mismatching type of field: "+f.getType().getName()+" v "+field.getType().getName());    }   }