javac编译找不到符号.doc

javac 编译找不到符号 问题描述： javac course.java course.java:31:找不到符号 符号：类sqlBean 位置：类bean.course sqlBean db=new sqlBean ; …… course.java和sqlBean.java及其他一些文件同放于bean文件夹下 course.java: package bean; import java.sql.*; public class course { private String id; private String name; private String dep; private String prepare; private int mark; public void setPrepare(String s){prepare=s;} public String getPrepare(){return prepare;} public void setMark(int s){mark=s;} public int getMark(){return mark;} public void setDep(String s){dep=s;} public String getDep(){return dep;} public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public ResultSet getPrepares(){ //得到所能选择的预修课 String sql=select name,id from course ; sqlBean db = new sqlBean(); ResultSet rs = db.executeQuery(sql); return rs; } public String getPrepareDep(){ //察看预修课所在系 String s=no; String sql=select dep from course where id= prepare ; sqlBean db = new sqlBean(); try{ ResultSet rs = db.executeQuery(sql); if(rs.next()){ s=rs.getString(dep); } }catch(Exception e){ e.getMessage();} return s;} public ResultSet getCourse(){ //察看所有课程 String sql=select * from course ; sqlBean db= new sqlBean(); ResultSet rs = db.executeQuery(sql); return rs; } public int deleteCourse(String id){ int num=0; String sql=delete from Course where id = id ; sqlBean db= new sqlBean(); num=db.executeDelete(sql); return num; } public String getPrepareDep(String id){ String dep=; String sql=select dep from course where id= id ; sqlBean db= new sqlBean(); try{ ResultSet rs = db.executeQuery(sql); if(rs.next()) dep=rs.getString(dep); }catch(SQLException e){System.out.print(e.toString());} return dep; } public void updateCourse(String id){ String sql=update course  set name= name ,prepare= prepare , dep= dep ,mark= mark  where id= id ; sqlBean