看看有关问题出在什么地方

       private static DatabaseManager dbm = new DatabaseManager("codetable", 1000,            "com.mysql.jdbc.Driver", "jdbc:mysql://localhost:3306/codetable",            "root", "root");    public static void method2() {        try {            List<CustTable> list = new ArrayList<CustTable>();            List<CustTable> cutList = (List<CustTable>) dbm.executeQuery(list,                    "select * from custtable");            for (int i = 0; i < cutList.size(); i++) {                System.out.println(cutList.get(i).getCustId());//异常产生地方                // System.out.println(cutList.get(i).getClass());            }            dbm.close();        } catch (DatabaseException e) {            e.printStackTrace();        }    }package com.mainClass;public class CustTable {    private String custId;    private String value;    private String codeNum;    private String valueId;    public CustTable() {    }    public CustTable(String custId) {        this.custId = custId;    }    public CustTable(String custId, String value, String codeNum, String valueId) {        this.custId = custId;        this.value = value;        this.codeNum = codeNum;        this.valueId = valueId;    }    public String getCustId() {        return custId;    }    public void setCustId(String custId) {        this.custId = custId;    }    public String getValue() {        return value;    }    public void setValue(String value) {        this.value = value;    }    public String getCodeNum() {        return codeNum;    }    public void setCodeNum(String codeNum) {        this.codeNum = codeNum;    }    public String getValueId() {        return valueId;    }    public void setValueId(String valueId) {        this.valueId = valueId;    }    public String toString() {        return custId + ", " + value + ", " + codeNum + ", " + valueId;    }}