package org.apache.onami.logging.core;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
import static java.lang.String.format;
import static java.lang.reflect.Modifier.isFinal;
import java.lang.reflect.Field;
import com.google.inject.MembersInjector;
import com.google.inject.ProvisionException;
/**
* The abstract Logger injector implementation, takes care of injecting the
* concrete Logger implementation to the logged filed.
*/
public abstract class AbstractLoggerInjector<L>
implements MembersInjector<L>
{
/**
* The logger field has to be injected.
*/
private final Field field;
/**
* Creates a new Logger injector.
*
* @param field the logger field has to be injected.
*/
public AbstractLoggerInjector( Field field )
{
this.field = field;
this.field.setAccessible(true);
}
/**
* {@inheritDoc}
*/
public final void injectMembers( Object target )
{
if ( isFinal( field.getModifiers() ) )
{
return;
}
try
{
if ( field.get( target ) == null )
{
field.set( target, createLogger( target.getClass() ) );
}
}
catch ( Exception e )
{
throw new ProvisionException( format( "Impossible to set logger for field '%s', see nested exception: %s",
field, e.getMessage() ) );
}
}
/**
* Creates a new Logger implementation for the specified Class.
*
* @return a new Logger implementation.
*/
protected abstract L createLogger(Class<?> klass);
}