/*
* Copyright 2004 The Apache Software Foundation.
*
* 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.apache.log4j.joran.action;
import javax.naming.Context;
import javax.naming.NamingException;
import javax.naming.InitialContext;
import org.apache.log4j.joran.spi.ExecutionContext;
import org.apache.log4j.spi.ErrorItem;
import org.xml.sax.Attributes;
/**
* This action looks up JNDI properties specified in the configuration
* file and adds them to the Joran <code>ExecutionContext</code>. The
* element in the configuration file should have an attribute called
* "jndiName". This attribute will be the key to the naming context lookup,
* as well as the key to the <code>ExecutionContext</code> properties. If a value
* is found whose name matches the given jndiName, it will be placed
* in the ExecutionContext's properties.
*
* @author Yoav Shapira
*/
public class JndiSubstitutionPropertyAction extends Action {
/**
* The attribute name specifying the JNDI variable to lookup.
*/
private static final String JNDI_ATTR = "jndiName";
/**
* The naming context.
*/
private Context namingContext;
/**
* Returns the naming context for lookups.
*
* @return The context (may be null)
*/
protected Context getNamingContext() {
return namingContext;
}
/**
* Creates the naming context. This is an expensive
* operation.
*
* @throws NamingException If an error occurs
*/
protected void findNamingContext() throws NamingException {
if(getNamingContext() != null) {
getLogger().warn("Overwriting existing naming context.");
}
// POSSIBLE TO-DO: add support for properties
// passed to the initial context, e.g. a factory,
// to enable things like a remote context.
InitialContext ic = new InitialContext();
namingContext = (Context) ic.lookup("java:comp/env");
}
/**
* @see org.apache.joran.Action#begin.
*/
public void begin(final ExecutionContext ec, final String name, final Attributes attributes) {
if(getLogger().isDebugEnabled()) {
getLogger().debug(getClass().getName() +
": begin({}, " + name + ", {}): here.", ec, attributes);
}
// If first time, create and locate context: expensive operation.
if(getNamingContext() == null) {
try {
findNamingContext();
} catch (Exception e) {
getLogger().error("Couldn't find JNDI naming context: ", e);
ec.addError(new ErrorItem("Couldn't find JNDI naming context.", e));
}
}
String jndiName = attributes.getValue(JNDI_ATTR);
if((jndiName == null) || (jndiName.trim().length() < 1)) {
getLogger().warn("Missing {} attribute, ignoring.", JNDI_ATTR);
} else if(getNamingContext() != null){
Object value = null;
try {
value = getNamingContext().lookup(jndiName);
} catch (Exception e) {
getLogger().error("Error looking up " + jndiName + ": ", e);
ec.addError(new ErrorItem("Error looking up " + jndiName, e));
}
if(value == null) {
getLogger().warn("No JNDI value found for {}.", jndiName);
} else if(! (value instanceof String)) {
getLogger().warn("Value for {} is not a String.", jndiName);
} else {
ec.addProperty(jndiName, (String) value);
}
} else {
getLogger().warn("Naming context is null, cannot lookup {}", jndiName);
}
}
/**
* @see org.apache.joran.Action#end.
*/
public void end(final ExecutionContext ec, final String name) {
}
}
// End of class: JndiSubstitutionPropertyAction.java