Filter.java

package org.springframework.roo.project;

import org.apache.commons.lang3.Validate;
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.w3c.dom.Element;

/**
 * Simplified immutable representation of a filter.
 * 
 * @author Alan Stewart
 * @since 1.1
 */
public class Filter implements Comparable<Filter> {

  private final String value;

  /**
   * Convenience constructor for creating a filter instance from a XML Element
   * 
   * @param element containing the property definition (required)
   */
  public Filter(final Element element) {
    Validate.notNull(element, "Element required");
    value = element.getTextContent();
  }

  /**
   * Convenience constructor creating a filter instance
   * 
   * @param value the property value (required)
   */
  public Filter(final String value) {
    Validate.notBlank(value, "Value required");
    this.value = value;
  }

  public int compareTo(final Filter o) {
    if (o == null) {
      throw new NullPointerException();
    }
    return value.compareTo(o.value);
  }

  @Override
  public boolean equals(final Object obj) {
    return obj instanceof Filter && compareTo((Filter) obj) == 0;
  }

  /**
   * The value of a filter
   * 
   * @return the value
   */
  public String getValue() {
    return value;
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + (value == null ? 0 : value.hashCode());
    return result;
  }

  @Override
  public String toString() {
    final ToStringBuilder builder = new ToStringBuilder(this);
    builder.append("value", value);
    return builder.toString();
  }
}