/*
* JBoss, Home of Professional Open Source
* Copyright 2011, Red Hat, Inc. and/or its affiliates, and individual
* contributors by the @authors tag. See the copyright.txt in the
* distribution for a full listing of individual contributors.
*
* 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.jboss.solder.properties.query;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import org.jboss.solder.properties.MethodProperty;
import org.jboss.solder.properties.Properties;
import org.jboss.solder.properties.Property;
/**
* <p>
* Queries a target class for properties that match certain criteria. A property
* may either be a private or public field, declared by the target class or
* inherited from a superclass, or a public method declared by the target class
* or inherited from any of its superclasses. For properties that are exposed
* via a method, the property must be a JavaBean style property, i.e. it must
* provide both an accessor and mutator method according to the JavaBean
* specification.
* </p>
* <p/>
* <p>
* This class is not thread-safe, however the result returned by the
* getResultList() method is.
* </p>
*
* @author Shane Bryzak
* @see PropertyQueries
* @see PropertyCriteria
*/
public class PropertyQuery<V> {
private final Class<?> targetClass;
private final List<PropertyCriteria> criteria;
PropertyQuery(Class<?> targetClass) {
if (targetClass == null) {
throw new IllegalArgumentException("targetClass parameter may not be null");
}
this.targetClass = targetClass;
this.criteria = new ArrayList<PropertyCriteria>();
}
/**
* Add a criteria to query
*
* @param criteria the criteria to add
*/
public PropertyQuery<V> addCriteria(PropertyCriteria criteria) {
this.criteria.add(criteria);
return this;
}
/**
* Get the first result from the query, causing the query to be run.
*
* @return the first result, or null if there are no results
*/
public Property<V> getFirstResult() {
List<Property<V>> results = getResultList();
return results.isEmpty() ? null : results.get(0);
}
/**
* Get the first result from the query that is not marked as read only,
* causing the query to be run.
*
* @return the first writable result, or null if there are no results
*/
public Property<V> getFirstWritableResult() {
List<Property<V>> results = getWritableResultList();
return results.isEmpty() ? null : results.get(0);
}
/**
* Get a single result from the query, causing the query to be run. An
* exception is thrown if the query does not return exactly one result.
*
* @return the single result
* @throws RuntimeException if the query does not return exactly one result
*/
public Property<V> getSingleResult() {
List<Property<V>> results = getResultList();
if (results.size() == 1) {
return results.get(0);
} else if (results.isEmpty()) {
throw new RuntimeException("Expected one property match, but the criteria did not match any properties on " + targetClass.getName());
} else {
throw new RuntimeException("Expected one property match, but the criteria matched " + results.size() + " properties on " + targetClass.getName());
}
}
/**
* Get a single result from the query that is not marked as read only,
* causing the query to be run. An exception is thrown if the query does not
* return exactly one result.
*
* @return the single writable result
* @throws RuntimeException if the query does not return exactly one result
*/
public Property<V> getWritableSingleResult() {
List<Property<V>> results = getWritableResultList();
if (results.size() == 1) {
return results.get(0);
} else if (results.isEmpty()) {
throw new RuntimeException("Expected one property match, but the criteria did not match any properties on " + targetClass.getName());
} else {
throw new RuntimeException("Expected one property match, but the criteria matched " + results.size() + " properties on " + targetClass.getName());
}
}
/**
* Get the result from the query, causing the query to be run.
*
* @return the results, or an empty list if there are no results
*/
public List<Property<V>> getResultList() {
return getResultList(false);
}
/**
* Get the non read only results from the query, causing the query to be run.
*
* @return the results, or an empty list if there are no results
*/
public List<Property<V>> getWritableResultList() {
return getResultList(true);
}
/**
* Get the result from the query, causing the query to be run.
*
* @param writable if this query should only return properties that are not
* read only
* @return the results, or an empty list if there are no results
*/
private List<Property<V>> getResultList(boolean writable) {
List<Property<V>> results = new ArrayList<Property<V>>();
// First check public accessor methods (we ignore private methods)
for (Method method : targetClass.getMethods()) {
if (!(method.getName().startsWith("is") || method.getName().startsWith("get")))
continue;
boolean match = true;
for (PropertyCriteria c : criteria) {
if (!c.methodMatches(method)) {
match = false;
break;
}
}
if (match) {
MethodProperty<V> property = Properties.<V>createProperty(method);
if (!writable || !property.isReadOnly()) {
results.add(property);
}
}
}
Class<?> cls = targetClass;
while (cls != null && !cls.equals(Object.class)) {
// Now check declared fields
for (Field field : cls.getDeclaredFields()) {
boolean match = true;
for (PropertyCriteria c : criteria) {
if (!c.fieldMatches(field)) {
match = false;
break;
}
}
Property<V> prop = Properties.<V>createProperty(field);
if (match && !resultsContainsProperty(results, prop.getName())) {
if (!writable || !prop.isReadOnly()) {
results.add(prop);
}
}
}
cls = cls.getSuperclass();
}
return results;
}
private boolean resultsContainsProperty(List<Property<V>> results, String propertyName) {
for (Property<V> p : results) {
if (propertyName.equals(p.getName()))
return true;
}
return false;
}
}