public void configPlugin(Plugins plugins) {
    String dbURL="jdbc:sqlserver://localhost:1433;DatabaseName=student";
    SQLServerDataSource dataSource = new SQLServerDataSource();
    dataSource.setURL(dbURL);
    dataSource.setUser("sa");
    dataSource.setPassword("619353515");
    ActiveRecordPlugin arp = new ActiveRecordPlugin(dataSource);
    arp.addMapping("Course","Cno" ,CModel.class);
    arp.addMapping("SC", "Sno",SCModel.class);
    arp.addMapping("Student","Sno", SModel.class);
    arp.setDialect(new SqlServerDialect());
    plugins.add(arp);

}

运行

CModel cModel = new CModel();
cModel.find("select *from Course");

出现错误

Exception in thread "main" java.lang.NullPointerException

at com.jfinal.plugin.activerecord.Model.find(Model.java:588)

at com.jfinal.plugin.activerecord.Model.find(Model.java:596)

at Test.main(Test.java:38)

这是怎么回事，要怎么解决呢