jsp问题

public List bookQuery(String type,String publish,String name){
//创建list集合
List list=null;
//实力化BaseDao类
BaseDao baseDao=new BaseDao();
//创建Connection对象
Connection con=null;
//创建PreparedStatement对象
PreparedStatement pStatement=null;
//创建结果集
ResultSet rs=null;
//需要执行在SQL语句
String sql="select * from book where book_type like '%?%' or book_publish like '%?%' or book_name like '%?%'";
try{
//得到Connection链接
con=baseDao.getConnection();

//通过Connection对象得到pStatement对象
pStatement=con.prepareStatement(sql);
//为参数赋值
pStatement.setString(1,type);
pStatement.setString(2,publish);
pStatement.setString(3,name);
//返回结果集
rs=pStatement.executeQuery();
//如果返回在结果集中有对象则循环读取
while(rs.next()){

//给实体类中在属性进行赋值
String bookname=rs.getString("book_name");
String bookpublish=rs.getString("book_publish");
String booktype=rs.getString("book_type");
String bookdate=rs.getString("book_date");
//实力化BookEntity类
BookEntity bookEntity=new BookEntity(bookname,bookpublish,booktype,bookdate);
//将bookEntity对象添加到Lis