common-types/src/main/java/org/apache/falcon/entity/v0/Entity.java

/**
 * 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.falcon.entity.v0;

import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamReader;
import java.io.StringReader;
import java.io.StringWriter;

/**
 * Base class that all entity jaxb object will extend.
 */
public abstract class Entity {
    public abstract String getName();

    public abstract String getTags();

    public abstract AccessControlList getACL();

    public EntityType getEntityType() {
        for (EntityType type : EntityType.values()) {
            if (type.getEntityClass().equals(getClass())) {
                return type;
            }
        }
        return null;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || !o.getClass().equals(this.getClass())) {
            return false;
        }

        Entity entity = (Entity) o;

        String name = getName();
        return !(name != null ? !name.equals(entity.getName()) : entity.getName() != null);
    }

    @Override
    public int hashCode() {
        String clazz = this.getClass().getName();

        String name = getName();
        int result = name != null ? name.hashCode() : 0;
        result = 31 * result + clazz.hashCode();
        return result;
    }

    @Override
    public String toString() {
        try {
            StringWriter stringWriter = new StringWriter();
            Marshaller marshaller = getEntityType().getMarshaller();
            marshaller.marshal(this, stringWriter);
            return stringWriter.toString();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static Entity fromString(EntityType type, String str) {
        try {
            Unmarshaller unmarshaler = type.getUnmarshaller();
            XMLInputFactory xif = SchemaHelper.createXmlInputFactory();
            XMLStreamReader xsr = xif.createXMLStreamReader(new StringReader(str));
            return (Entity) unmarshaler.unmarshal(xsr);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public String toShortString() {
        return "(" + getEntityType().name().toLowerCase() + ") " + getName();
    }

    public Entity copy() {
        return fromString(getEntityType(), toString());
    }
}