net.java.ao.schema.ddl.DDLForeignKey Maven / Gradle / Ivy

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/*
 * Copyright 2007 Daniel Spiewak
 * 
 * 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 net.java.ao.schema.ddl;

import net.java.ao.schema.Case;

/**
 * Database-agnostic representation of a foreign key constraint.  To
 * avoid unnecessary object creation (and to simplify schema parsing)
 * this class only contains table and field names, rather than
 * the full DDL representation.  Basically, this class just wraps around
 * the data represented by a fully-rendered foreign key constraint.
 *
 * This class also defines the convention used to determine foreign
 * key names.  It is important that this convention be observed by DDL
 * renderings (i.e. database providers) otherwise migrations will do
 * strange things.
 *
 * @author Daniel Spiewak
 */
public class DDLForeignKey {
    private String field = "";

    private String domesticTable = "";
    private String table = "";
    private String foreignField = "";

    public String getField() {
        return field;
    }

    public void setField(String field) {
        this.field = field;
    }

    public String getTable() {
        return table;
    }

    public void setTable(String table) {
        this.table = table;
    }

    public String getForeignField() {
        return foreignField;
    }

    public void setForeignField(String foreignField) {
        this.foreignField = foreignField;
    }

    public String getFKName() {
        return new StringBuilder()
                .append("fk_")
                .append(Case.LOWER.apply(getDomesticTable()))
                .append('_')
                .append(Case.LOWER.apply(getField()))
                .toString();
    }

    public String getDomesticTable() {
        return domesticTable;
    }

    public void setDomesticTable(String domesticTable) {
        this.domesticTable = domesticTable;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }

        if (obj instanceof DDLForeignKey) {
            DDLForeignKey key = (DDLForeignKey) obj;

            if (key.field.equals(field) && key.foreignField.equals(foreignField) && key.table.equals(table) && key.domesticTable.equals(domesticTable)) {
                return true;
            }
        }

        return false;
    }

    @Override
    public int hashCode() {
        return field.hashCode() + table.hashCode() + foreignField.hashCode() + domesticTable.hashCode();
    }

    @Override
    public String toString() {
        return getDomesticTable() + "." + getField() + " => " + getTable() + "." + getForeignField();
    }
}