mysql的模糊查询语句怎么写？：报错

代码如下，我想在学生表中模糊查询名字。
报错
java.sql.SQLException: Parameter index out of range (1 > number of parameters, which is 0).

public class SerchDao {

public List<Student> serch(String name) throws ClassNotFoundException, SQLException{

ArrayList<Student> list=new ArrayList<Student>();

//得到数据库的连接

Connection conn=MysqlConn.getConn();

//创建sql语句

String sql="select * from student where name like '?%'";

//创建执行对象

PreparedStatement prep=conn.prepareStatement(sql);

//设置占位符参数

prep.setString(1, name);

ResultSet rs=prep.executeQuery();

while(rs.next()){

int idDB=Integer.parseInt(rs.getObject("id").toString());

String nameDB=rs.getObject("name").toString();

int ageDB=Integer.parseInt(rs.getObject("age").toString());

String sexDB=rs.getObject("sex").toString();

//保存对象的信息

Student stu=new Student();

stu.setId(idDB);

stu.setName(nameDB);

stu.setAge(ageDB);

stu.setSex(sexDB);

list.add(stu);

}

return list;

}

}