package lockmgr;public class XObj{    protected int xid = 0;        XObj() {        super();        this.xid = 0;    }        XObj(int xid) {        super();                if (xid > 0) {            this.xid = xid;        } else {            this.xid = 0;        }    }        public String toString() {        String outString = new String(this.getClass() + "::xid(" + this.xid + ")");        return outString;    }        public int getXId() {        return this.xid;    }        public int hashCode() {        return this.xid;    }        public boolean equals(Object xobj) {        if (xobj == null) return false;                if (xobj instanceof XObj) {            if (this.xid == ((XObj)xobj).getXId()) {                return true;            }        }        return false;    }        public Object clone() {        try {            XObj xobj = (XObj)super.clone();            xobj.SetXId(this.xid);            return xobj;        } catch (CloneNotSupportedException clonenotsupported) {            return null;        }    }        public int key() {        return this.xid;    }    // Used by clone.    public void SetXId(int xid) {        if (xid > 0) {            this.xid = xid;        }        return;    }}