/*
* 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.
*/
package org.apache.jackrabbit.core.config;
import org.apache.commons.collections.BeanMap;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Properties;
import java.util.Map;
import java.util.HashMap;
import java.util.Collections;
import java.io.InputStream;
import java.io.IOException;
/**
* Bean configuration class. BeanConfig instances contain the class name
* and property information required to instantiate a class that conforms
* with the JavaBean conventions.
*/
public class BeanConfig<T> {
private static Logger log = LoggerFactory.getLogger(BeanConfig.class);
private static final Map<String, String> DEPRECATIONS;
static {
try {
Map<String, String> temp = new HashMap<String, String>();
Properties props = new Properties();
InputStream in = BeanConfig.class.getResourceAsStream("deprecated-classes.properties");
try {
props.load(in);
} finally {
in.close();
}
for (Map.Entry<Object, Object> entry : props.entrySet()) {
temp.put(entry.getKey().toString(), entry.getValue().toString());
}
DEPRECATIONS = Collections.unmodifiableMap(temp);
} catch (IOException e) {
throw new InternalError("failed to read deprecated classes");
}
}
/** The default class loader used by all instances of this class */
private static ClassLoader defaultClassLoader =
BeanConfig.class.getClassLoader();
/**
* The current class loader used by this instance to create instances of
* configured classes.
*/
private ClassLoader classLoader = getDefaultClassLoader();
/**
* The class name of the configured bean.
*/
private final String className;
/**
* The initial properties of the configured bean.
*/
private final Properties properties;
/**
* Flag to validate the configured bean property names against
* the configured bean class. By default this is <code>true</code>
* to prevent incorrect property names. However, in some cases this
* validation should not be performed as client classes may access
* the configuration parameters directly through the
* {@link #getParameters()} method.
*
* @see <a href="https://issues.apache.org/jira/browse/JCR-1920">JCR-1920</a>
*/
private boolean validate = true;
/**
* Creates a bean configuration. Note that a copy of the given
* bean properties is stored as a part of the created configuration
* object. Thus the caller is free to modify the given properties
* once the configuration object has been created.
*
* @param className class name of the bean
* @param properties initial properties of the bean
*/
public BeanConfig(String className, Properties properties) {
if (DEPRECATIONS.containsKey(className)) {
String replacement = DEPRECATIONS.get(className);
log.info("{} is deprecated. Please use {} instead", className, replacement);
className = replacement;
}
this.className = className;
this.properties = (Properties) properties.clone();
}
/**
* Copies a bean configuration.
*
* @param config the configuration to be copied
*/
public BeanConfig(BeanConfig config) {
this(config.getClassName(), config.getParameters());
}
/**
* Allows subclasses to control whether the configured bean property
* names should be validated.
*
* @param validate flag to validate the configured property names
*/
protected void setValidate(boolean validate) {
this.validate = validate;
}
/**
* Returns the class name of the configured bean.
*
* @return class name of the bean
*/
public String getClassName() {
return className;
}
/**
* Returns the initial properties of the configured bean.
*
* @return initial properties of the bean
*/
public Properties getParameters() {
return properties;
}
/**
* Creates a new instance of the configured bean class.
*
* @return new bean instance
* @throws ConfigurationException on bean configuration errors
*/
public Object newInstance() throws ConfigurationException {
try {
// Instantiate the object using the default constructor
Class<?> objectClass =
Class.forName(getClassName(), true, getClassLoader());
Object object = objectClass.newInstance();
// Set all configured bean properties
BeanMap map = new BeanMap(object);
for (Object key : map.keySet()) {
String value = properties.getProperty(key.toString());
if (value != null) {
map.put(key, value);
}
}
if (validate) {
// Check that no invalid property names were configured
for (Object key : properties.keySet()) {
if (!map.containsKey(key)
&& properties.getProperty(key.toString()) != null) {
String msg =
"Configured class " + object.getClass().getName()
+ " does not contain the property " + key
+ ". Please fix the repository configuration.";
log.error(msg);
throw new ConfigurationException(msg);
}
}
}
return (T) object;
} catch (ClassNotFoundException e) {
throw new ConfigurationException(
"Configured bean implementation class " + getClassName()
+ " was not found.", e);
} catch (InstantiationException e) {
throw new ConfigurationException(
"Configured bean implementation class " + getClassName()
+ " can not be instantiated.", e);
} catch (IllegalAccessException e) {
throw new ConfigurationException(
"Configured bean implementation class " + getClassName()
+ " is protected.", e);
}
}
//---------- Configurable class loader support ----------------------------
/**
* Returns the current <code>ClassLoader</code> used to instantiate objects
* in the {@link #newInstance()} method.
*
* @see #newInstance()
* @see #setClassLoader(ClassLoader)
* @see #getDefaultClassLoader()
* @see #setDefaultClassLoader(ClassLoader)
*/
public ClassLoader getClassLoader() {
return classLoader;
}
/**
* Sets the <code>ClassLoader</code> used to instantiate objects in the
* {@link #newInstance()} method.
*
* @param classLoader The class loader to set on this instance. If this is
* <code>null</code> the system class loader will be used, which may
* lead to unexpected class loading failures.
*
* @see #newInstance()
* @see #getClassLoader()
* @see #getDefaultClassLoader()
* @see #setDefaultClassLoader(ClassLoader)
*/
public void setClassLoader(ClassLoader classLoader) {
this.classLoader = classLoader;
}
/**
* Returns the current <code>ClassLoader</code> used for new instances of
* this class as the loader used to instantiate objects in the
* {@link #newInstance()} method.
*
* @see #newInstance()
* @see #getClassLoader()
* @see #setClassLoader(ClassLoader)
* @see #setDefaultClassLoader(ClassLoader)
*/
public static ClassLoader getDefaultClassLoader() {
return defaultClassLoader;
}
/**
* Sets the <code>ClassLoader</code> used for new instances of this class as
* the loader to instantiate objects in the {@link #newInstance()} method.
*
* @param classLoader The class loader to set as the default class loader.
* If this is <code>null</code> the system class loader will be used,
* which may lead to unexpected class loading failures.
*
* @see #newInstance()
* @see #getClassLoader()
* @see #setClassLoader(ClassLoader)
* @see #getDefaultClassLoader()
*/
public static void setDefaultClassLoader(ClassLoader classLoader) {
defaultClassLoader = classLoader;
}
}