+/*
+ * 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);
+ }
+}