ForeignKey.java

package org.springframework.roo.addon.dbre.addon.model;

import java.util.LinkedHashSet;
import java.util.Set;

import org.apache.commons.lang3.Validate;

/**
 * Represents a database foreign key.
 * <p>
 * A foreign key is modeled from the
 * {@link java.sql.DatabaseMetaData#getImportedKeys(String, String, String)} or
 * {@link java.sql.DatabaseMetaData#getExportedKeys(String, String, String)}
 * methods.
 * 
 * @author Alan Stewart
 * @since 1.1
 */
public class ForeignKey {

  /** Whether the foreign key is an imported or exported key */
  private boolean exported;

  /** The schema name of the foreign table. */
  private String foreignSchemaName;

  /** The target table. */
  private Table foreignTable;

  /** The name of the foreign (target) table. */
  private final String foreignTableName;

  /**
   * The sequence number of the key within the table for a given foreign
   * table.
   */
  private Short keySequence;

  /** The name of the foreign key, may be <code>null</code>. */
  private final String name;

  /** The action to perform when the referenced row is deleted. */
  private CascadeAction onDelete = CascadeAction.NONE;

  /** The action to perform when the value of the referenced column changes. */
  private CascadeAction onUpdate = CascadeAction.NONE;

  /** The references between local and remote columns. */
  private final Set<Reference> references = new LinkedHashSet<Reference>();

  ForeignKey(final String name, final String foreignTableName) {
    this.name = name;
    this.foreignTableName = foreignTableName;
  }

  public void addReference(final Reference reference) {
    Validate.notNull(reference, "Reference required");
    references.add(reference);
  }

  @Override
  public boolean equals(final Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj == null) {
      return false;
    }
    if (getClass() != obj.getClass()) {
      return false;
    }
    final ForeignKey other = (ForeignKey) obj;
    if (exported != other.exported) {
      return false;
    }
    if (foreignSchemaName == null) {
      if (other.foreignSchemaName != null) {
        return false;
      }
    } else if (!foreignSchemaName.equals(other.foreignSchemaName)) {
      return false;
    }
    if (foreignTableName == null) {
      if (other.foreignTableName != null) {
        return false;
      }
    } else if (!foreignTableName.equals(other.foreignTableName)) {
      return false;
    }
    if (name == null) {
      if (other.name != null) {
        return false;
      }
    } else if (!name.equals(other.name)) {
      return false;
    }
    return true;
  }

  String getForeignSchemaName() {
    return foreignSchemaName;
  }

  public Table getForeignTable() {
    return foreignTable;
  }

  String getForeignTableName() {
    return foreignTableName;
  }

  public Short getKeySequence() {
    return keySequence;
  }

  public String getName() {
    return name;
  }

  public CascadeAction getOnDelete() {
    return onDelete;
  }

  public CascadeAction getOnUpdate() {
    return onUpdate;
  }

  public int getReferenceCount() {
    return references.size();
  }

  public Set<Reference> getReferences() {
    return references;
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + (exported ? 1231 : 1237);
    result = prime * result + (foreignSchemaName == null ? 0 : foreignSchemaName.hashCode());
    result = prime * result + (foreignTableName == null ? 0 : foreignTableName.hashCode());
    result = prime * result + (name == null ? 0 : name.hashCode());
    return result;
  }

  public boolean hasLocalColumn(final Column column) {
    for (final Reference reference : references) {
      if (reference.getLocalColumn().equals(column)) {
        return true;
      }
    }
    return false;
  }

  public boolean isExported() {
    return exported;
  }

  public void setExported(final boolean exported) {
    this.exported = exported;
  }

  void setForeignSchemaName(final String foreignSchemaName) {
    this.foreignSchemaName = foreignSchemaName;
  }

  void setForeignTable(final Table foreignTable) {
    this.foreignTable = foreignTable;
  }

  public void setKeySequence(final Short keySequence) {
    this.keySequence = keySequence;
  }

  public void setOnDelete(final CascadeAction onDelete) {
    this.onDelete = onDelete;
  }

  public void setOnUpdate(final CascadeAction onUpdate) {
    this.onUpdate = onUpdate;
  }

  @Override
  public String toString() {
    return String
        .format(
            "ForeignKey [name=%s, exported=%s, foreignTableName=%s, foreignSchemaName=%s, onUpdate=%s, onDelete=%s, keySequence=%s, references=%s]",
            name, exported, foreignTableName, foreignSchemaName, onUpdate, onDelete, keySequence,
            references);
  }
}