com.wzk.CMS.Users cannot be cast to java.util.List

Question

恩 我编写了一个 Users类 。。。
[code="java"]
package com.wzk.CMS;
public class Users {

 private int id;
 private int wor_id;
 private int deb_id;            
 private int war_id;           
 private int dep_id;        
 private int fil_id;      
 private int cul_id;    
 private int dut_id;     
 private String username;   
 private String password;
 private String name;
public int getDeb_id() {
    return deb_id;
}
public void setDeb_id(int debId) {
    deb_id = debId;
}
public int getDep_id() {
    return dep_id;
}
public void setDep_id(int depId) {
    dep_id = depId;
}
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}
public int getWor_id() {
    return wor_id;
}
public void setWor_id(int worId) {
    wor_id = worId;
}
public int getWar_id() {
    return war_id;
}
public void setWar_id(int warId) {
    war_id = warId;
}
public int getFil_id() {
    return fil_id;
}
public void setFil_id(int filId) {
    fil_id = filId;
}
public int getCul_id() {
    return cul_id;
}
public void setCul_id(int culId) {
    cul_id = culId;
}
public int getDut_id() {
    return dut_id;
}
public void setDut_id(int dutId) {
    dut_id = dutId;
}
public String getUsername() {
    return username;
}
public void setUsername(String username) {
    this.username = username;
}
public String getPassword() {
    return password;
}
public void setPassword(String password) {
    this.password = password;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}

}
[/code]
然后 编写了 一个 DAO实现方法 其中声明private static final String select_users_sql="select * from users order by id desc" ;
[code="java"]
//****************读取表中所有记录*******************

public List getUserList() {

    QueryRunner qr=getQueryRunner();
    List userList=null;

    try {
        userList=(List)qr.query(select_users_sql, new BeanHandler(Users.class));

    } catch (Exception e) {
        e.printStackTrace();
    }

    return userList;
}

[/code]

编译运行后 报错
[code="java"]
java.lang.ClassCastException: com.wzk.CMS.Users cannot be cast to java.util.List
at com.wzk.CMS.dao.DaoJdbc.getUserList(DaoJdbc.java:81)
at com.wzk.CMS.servlet.UsersServlet.getUsersList(UsersServlet.java:73)
at com.wzk.CMS.servlet.UsersServlet.doPost(UsersServlet.java:34)
at com.wzk.CMS.servlet.UsersServlet.doGet(UsersServlet.java:22)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)

[/code]

UsersServlet代码 为
[code="java"]
public void getUsersList(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
Dao dao = new DaoJdbc();
List userList = dao.getUserList();
request.setAttribute("userList", userList);
request.getRequestDispatcher("/userList.jsp")
.forward(request, response);

}

[/code]
怎么办呀

Answer 1

userList=(List)qr.query(select_users_sql, new BeanHandler(Users.class));

改成：
userList=(List)qr.query(select_users_sql, new BeanListHandler(Users.class));