org.picketlink.common.properties.query.PropertyQuery Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source
*
* Copyright 2013 Red Hat, Inc. and/or its affiliates.
*
* 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.picketlink.common.properties.query;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import org.picketlink.common.properties.MethodProperty;
import org.picketlink.common.properties.Properties;
import org.picketlink.common.properties.Property;
/**
*
* 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.
*
*
*
* This class is not thread-safe, however the result returned by the
* getResultList() method is.
*
*
* @see PropertyQueries
* @see PropertyCriteria
*/
public class PropertyQuery
{
private final Class targetClass;
private final List criteria;
PropertyQuery(Class targetClass)
{
if (targetClass == null)
{
throw new IllegalArgumentException("targetClass parameter may not be null");
}
this.targetClass = targetClass;
this.criteria = new ArrayList();
}
/**
* Add a criteria to query
*
* @param criteria the criteria to add
*/
public PropertyQuery 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 getFirstResult()
{
List> 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 getFirstWritableResult()
{
List> 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 getSingleResult()
{
List> 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 getWritableSingleResult()
{
List> 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> 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> 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> getResultList(boolean writable)
{
List> results = new ArrayList>();
// 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 property = Properties.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 prop = Properties.createProperty(field);
if (match && !resultsContainsProperty(results, prop.getName()))
{
if (!writable || !prop.isReadOnly())
{
results.add(prop);
}
}
}
cls = cls.getSuperclass();
}
return results;
}
private boolean resultsContainsProperty(List> results, String propertyName)
{
for (Property p : results)
{
if (propertyName.equals(p.getName()))
{
return true;
}
}
return false;
}
}