org.apache.log4j.config.PropertyGetter Maven / Gradle / Ivy
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* 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.log4j.config;
import org.apache.log4j.Priority;
import org.apache.log4j.helpers.LogLog;
import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.io.InterruptedIOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/**
Used for inferring configuration information for a log4j's component.
@author Anders Kristensen
*/
public class PropertyGetter {
protected static final Object[] NULL_ARG = new Object[] {};
protected Object obj;
protected PropertyDescriptor[] props;
public interface PropertyCallback {
void foundProperty(Object obj, String prefix, String name, Object value);
}
/**
Create a new PropertyGetter for the specified Object. This is done
in prepartion for invoking {@link
#getProperties(PropertyGetter.PropertyCallback, String)} one or
more times.
@param obj the object for which to set properties */
public
PropertyGetter(Object obj) throws IntrospectionException {
BeanInfo bi = Introspector.getBeanInfo(obj.getClass());
props = bi.getPropertyDescriptors();
this.obj = obj;
}
public
static
void getProperties(Object obj, PropertyCallback callback, String prefix) {
try {
new PropertyGetter(obj).getProperties(callback, prefix);
} catch (IntrospectionException ex) {
LogLog.error("Failed to introspect object " + obj, ex);
}
}
public
void getProperties(PropertyCallback callback, String prefix) {
for (int i = 0; i < props.length; i++) {
Method getter = props[i].getReadMethod();
if (getter == null) continue;
if (!isHandledType(getter.getReturnType())) {
//System.err.println("Ignoring " + props[i].getName() +" " + getter.getReturnType());
continue;
}
String name = props[i].getName();
try {
Object result = getter.invoke(obj, NULL_ARG);
//System.err.println("PROP " + name +": " + result);
if (result != null) {
callback.foundProperty(obj, prefix, name, result);
}
} catch (IllegalAccessException ex) {
LogLog.warn("Failed to get value of property " + name);
} catch (InvocationTargetException ex) {
if (ex.getTargetException() instanceof InterruptedException
|| ex.getTargetException() instanceof InterruptedIOException) {
Thread.currentThread().interrupt();
}
LogLog.warn("Failed to get value of property " + name);
} catch (RuntimeException ex) {
LogLog.warn("Failed to get value of property " + name);
}
}
}
protected
boolean isHandledType(Class type) {
return String.class.isAssignableFrom(type) ||
Integer.TYPE.isAssignableFrom(type) ||
Long.TYPE.isAssignableFrom(type) ||
Boolean.TYPE.isAssignableFrom(type) ||
Priority.class.isAssignableFrom(type);
}
}