GAV.java

package org.springframework.roo.project;

import java.util.Arrays;

import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.Validate;

/**
 * The combination of Maven-style groupId, artifactId, and version.
 * 
 * @author Andrew Swan
 * @since 1.2.0
 */
public class GAV implements Comparable<GAV> {

  /**
   * Returns an instance based on the given concatenated Maven coordinates.
   * 
   * @param coordinates the groupId, artifactId, and version, separated by
   *            {@link MavenUtils#COORDINATE_SEPARATOR}
   * @return a non-blank instance
   * @throws IllegalArgumentException if the string is not formatted as
   *             explained above, or if any of the elements are themselves
   *             invalid.
   */
  public static GAV getInstance(final String coordinates) {
    final String[] coordinateArray =
        ArrayUtils.nullToEmpty(StringUtils.split(coordinates, MavenUtils.COORDINATE_SEPARATOR));
    Validate.isTrue(coordinateArray.length == 3, "Expected three coordinates, but found "
        + coordinateArray.length + ": " + Arrays.toString(coordinateArray) + "; did you use the '"
        + MavenUtils.COORDINATE_SEPARATOR + "' separator?");
    return new GAV(coordinateArray[0], coordinateArray[1], coordinateArray[2]);
  }

  private final String artifactId;
  private final String groupId;
  private final String version;

  /**
   * Constructor
   * 
   * @param groupId must be a valid Maven ID
   * @param artifactId must be a valid Maven ID
   * @param version cannot be blank
   */
  public GAV(final String groupId, final String artifactId, final String version) {
    // Check
    Validate.isTrue(MavenUtils.isValidMavenId(groupId), "Invalid groupId '%s'", groupId);
    Validate.isTrue(MavenUtils.isValidMavenId(artifactId), "Invalid artifactId '%s'", artifactId);
    Validate.notBlank(version, "Version is required for %s:%s", groupId, artifactId);

    // Assign
    this.groupId = groupId;
    this.artifactId = artifactId;
    this.version = version;
  }

  public int compareTo(final GAV other) {
    Validate.notNull(other, "Cannot compare %s to null", this);
    int result = groupId.compareTo(other.getGroupId());
    if (result == 0) {
      result = artifactId.compareTo(other.getArtifactId());
    }
    if (result == 0) {
      result = version.compareTo(other.getVersion());
    }
    return result;
  }

  @Override
  public boolean equals(final Object other) {
    return other == this || other instanceof GAV && compareTo((GAV) other) == 0;
  }

  public String getArtifactId() {
    return artifactId;
  }

  public String getGroupId() {
    return groupId;
  }

  public String getVersion() {
    return version;
  }

  @Override
  public int hashCode() {
    return artifactId.hashCode();
  }

  @Override
  public String toString() {
    // For debugging
    return StringUtils.join(ArrayUtils.toArray(groupId, artifactId, version), ":");
  }
}