mybatis mapper互相引用resultMap啟動出錯的解決

package pojo;
import java.io.Serializable;
import java.util.Date;
/**
 * 系統日志
 *
 * @author Administrator
 */
public class Log implements Serializable {
    private static final long serialVersionUID = -7372303516713218870L;
    private int id;//
    private int userId;//
    private String userName;
    private Date createDate;//創建日期
    private String content;//日志內容
    private String operation;//用戶所做的操作
    private String url;//用戶所做的操作
    public Log() {
    }
    public Log(int id, int userId, String userName, Date createDate, String content, String operation, String url) {
        this.id = id;
        this.userId = userId;
        this.userName = userName;
        this.createDate = createDate;
        this.content = content;
        this.operation = operation;
        this.url = url;
    }
    public static long getSerialVersionUID() {
        return serialVersionUID;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public int getUserId() {
        return userId;
    }
    public void setUserId(int userId) {
        this.userId = userId;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public Date getCreateDate() {
        return createDate;
    }
    public void setCreateDate(Date createDate) {
        this.createDate = createDate;
    }
    public String getContent() {
        return content;
    }
    public void setContent(String content) {
        this.content = content;
    }
    public String getOperation() {
        return operation;
    }
    public void setOperation(String operation) {
        this.operation = operation;
    }
    public String getUrl() {
        return url;
    }
    public void setUrl(String url) {
        this.url = url;
    }
    @Override
    public String toString() {
        return "Log{" +
                "id=" + id +
                ", userId=" + userId +
                ", userName='" + userName + '\'' +
                ", createDate=" + createDate +
                ", content='" + content + '\'' +
                ", operation='" + operation + '\'' +
                ", url='" + url + '\'' +
                '}';
    }
}

public List<Log> listAll();
    <resultMap id="LogMapper" type="Log">
        <id column="userid" property="userId"/>
        <result column="username" property="userName"/>
        <result column="content" property="content"/>
        <result column="operation" property="operation"/>
        <result column="createdate" property="createDate"/>
        <result column="url" property="url"/>
    </resultMap>
    <select id="listAll"   resultMap="LogMapper">
        SELECT * FROM t_log
    </select>