/*
* 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.ambari.server.collections.functors;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import org.apache.ambari.server.collections.Predicate;
/**
* {@link ContainsPredicate} is a predicate implementation testing whether a string value exists
* within some set of strings.
* <p>
* It it expected that the data supplied to the {@link #evaluate(Object)} method is as {@link Set}
* of {@link String}s retrieved from a context (a {@link Map} of keys to values, where each value
* can be an explicit value or a {@link Map} of values creating a tree structure.
*/
public class ContainsPredicate extends OperationPredicate {
/**
* The name of this {@link Predicate} implementation
*/
public static final String NAME = "contains";
/**
* The value to test for
*/
private final String value;
/**
* Creates a new {@link ContainsPredicate} using the given {@link Map} of data.
* <p>
* It is expected that the map contains a single {@link java.util.Map.Entry} where the key name
* is "contains" and the value is a {@link Collection} of 2 {@link String}s. The first value
* should be the key to use when retrieving data from the context, which should resolve to a
* {@link Set} of {@link String}s (or null). The second value should be the value to check for
* existing in the relevant set.
*
* @return a new {@link ContainsPredicate}
*/
public static ContainsPredicate fromMap(Map<String, Object> map) {
Object data = (map == null) ? null : map.get(NAME);
if (data == null) {
throw new IllegalArgumentException("Missing data for '" + NAME + "' operation");
} else if (data instanceof Collection) {
Collection<?> collection = (Collection) data;
if (collection.size() == 2) {
Iterator<?> iterator = collection.iterator();
Object d1 = iterator.next();
Object d2 = iterator.next();
if ((d1 instanceof String) && (d2 instanceof String)) {
return new ContainsPredicate(new ContextTransformer((String) d1), (String) d2);
} else {
throw new IllegalArgumentException(String.format("Unexpected data types: %s and %s", d1.getClass().getName(), d2.getClass().getName()));
}
} else {
throw new IllegalArgumentException(String.format("Missing data for '" + NAME + "' operation - 2 predicates are needed, %d found", collection.size()));
}
} else {
throw new IllegalArgumentException(String.format("Unexpected data type for '" + NAME + "' operation - %s", data.getClass().getName()));
}
}
/**
* Constructor
*
* @param transformer the {@link ContextTransformer} configured with the context key to find
* @param value the value to test
*/
public ContainsPredicate(ContextTransformer transformer, String value) {
super(NAME, transformer);
this.value = value;
}
/**
* Gets the test value
*
* @return a string
*/
public String getValue() {
return value;
}
@Override
protected boolean evaluateTransformedData(Object data) {
return (this.value != null) && (data instanceof Set) && ((Set<?>) data).contains(this.value);
}
@Override
public Map<String, Object> toMap() {
return Collections.<String, Object>singletonMap(NAME,
new ArrayList<>(Arrays.asList(getContextKey(), value)));
}
@Override
public int hashCode() {
return super.hashCode() +
(37 * ((this.value == null) ? 0 : this.value.hashCode()));
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
} else if (obj == null) {
return false;
} else if (super.equals(obj) && (obj instanceof ContainsPredicate) && (hashCode() == obj.hashCode())) {
ContainsPredicate p = (ContainsPredicate) obj;
return (value == null) ? (p.value == null) : value.equals(p.value);
} else {
return false;
}
}
}