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JSimpleDB classes that map Java model classes onto the core API.

There is a newer version: 3.6.1


/*
 * Copyright (C) 2015 Archie L. Cobbs. All rights reserved.
 */

package org.jsimpledb.change;

import org.jsimpledb.JObject;
import org.jsimpledb.JTransaction;

/**
 * Notification object that gets passed to {@link org.jsimpledb.annotation.OnChange @OnChange}-annotated methods
 * when a simple field changes.
 *
 * @param  the type of the object containing the changed field
 * @param  the type of the changed field
 */
public class SimpleFieldChange extends FieldChange {

    private final V oldValue;
    private final V newValue;

    /**
     * Constructor.
     *
     * @param jobj Java object containing the field that changed
     * @param storageId the storage ID of the affected field
     * @param fieldName the name of the field that changed
     * @param oldValue the old field value
     * @param newValue the new field value
     * @throws IllegalArgumentException if {@code jobj} or {@code fieldName} is null
     */
    public SimpleFieldChange(T jobj, int storageId, String fieldName, V oldValue, V newValue) {
        super(jobj, storageId, fieldName);
        this.oldValue = oldValue;
        this.newValue = newValue;
    }

    @Override
    public  R visit(ChangeSwitch target) {
        return target.caseSimpleFieldChange(this);
    }

    @Override
    public void apply(JTransaction jtx, JObject jobj) {
        jtx.writeSimpleField(jobj, this.getStorageId(), this.newValue, false);
    }

    /**
     * Get the value of the field before the change.
     *
     * @return the old field value
     */
    public V getOldValue() {
        return this.oldValue;
    }

    /**
     * Get the value of the field after the change.
     *
     * @return the new field value
     */
    public V getNewValue() {
        return this.newValue;
    }

// Object

    @Override
    public boolean equals(Object obj) {
        if (obj == this)
            return true;
        if (!super.equals(obj))
            return false;
        final SimpleFieldChange that = (SimpleFieldChange)obj;
        return (this.oldValue != null ? this.oldValue.equals(that.oldValue) : that.oldValue == null)
          && (this.newValue != null ? this.newValue.equals(that.newValue) : that.newValue == null);
    }

    @Override
    public int hashCode() {
        return super.hashCode()
          ^ (this.oldValue != null ? this.oldValue.hashCode() : 0)
          ^ (this.newValue != null ? this.newValue.hashCode() : 0);
    }

    @Override
    public String toString() {
        return "SimpleFieldChange[object=" + this.getObject() + ",field=\"" + this.getFieldName() + "\",oldValue="
          + this.oldValue + ",newValue=" + this.newValue + "]";
    }
}