Grails Java域类中的toString()导致

默认情况下,grails似乎会返回 <class name>:<id> 返回我想要的内容的toString()。当我尝试grails generate all标记类型时,出现以下错误:

java.lang.LinkageError: loader constraint violation: loader (instance of <bootloader>) previously initiated loading for a differen
t type with name "org/w3c/dom/NamedNodeMap"

我的代码如下。任何帮助都将不胜感激。

@Entity
@Table(name = "tagtype", catalog = "tigger")
@SuppressWarnings("serial")
public class Tagtype implements Serializable {

    /**
     * Attribute id.
     */
    private Integer id;

    /**
     * Attribute tagtype.
     */
    private String tagtype;

    /**
     * Attribute regexpression
     */
     private Regexpression regexpression;   

 . . .  

  @Override public String toString() {
    StringBuilder result = new StringBuilder();

    result.append(this.tagtype);

    return result.toString();
  }

}