package grad.util.homework;import java.util.*;import java.sql.*;import grad.util.DataBase;public class op_homework {  public op_homework() {  }  /**   * 查看指定課程所發布的全部作業   * @param sourseid   * @return   */  public ArrayList getAllHomeworkPub(String sourseid){     Connection conn=null;     Statement st=null;     ResultSet rs=null;     String sql ="select * from t_homework where course_code='"+sourseid+"' and type=1";     ArrayList al=new ArrayList();     try{       DataBase ds = new DataBase();       conn = ds.conn;       st = conn.createStatement();       rs = st.executeQuery(sql);       while (rs.next()) {          homework cs=new homework();          cs.setid(rs.getInt(1));          cs.settitle(rs.getString(2));          cs.setlink(rs.getString(3));          cs.setdate(rs.getString(4));          cs.settype(rs.getString(5));          cs.setcourse_code(rs.getString(6));          cs.setuser_id(rs.getString(7));          al.add(cs);       }       return al;     }catch(Exception e){System.out.println(e.getMessage());return null;}    }    /**     * 查詢指定課程作業 全部學生提交的作業     * @param sourseid     * @return     */public ArrayList getAllHomeworkCommit(String sourseid){     Connection conn=null;     Statement st=null;     ResultSet rs=null;     String sql ="select * from t_homework where course_code='"+sourseid+"' and type=2 order by user_id desc";     ArrayList al=new ArrayList();     try{       DataBase ds = new DataBase();       conn = ds.conn;       st = conn.createStatement();       rs = st.executeQuery(sql);       while (rs.next()) {          homework cs=new homework();          cs.setid(rs.getInt(1));          cs.settitle(rs.getString(2));          cs.setlink(rs.getString(3));          cs.setdate(rs.getString(4));          cs.settype(rs.getString(5));          cs.setcourse_code(rs.getString(6));          cs.setuser_id(rs.getString(7));          cs.setstatus(rs.getString(8));          al.add(cs);       }       return al;     }catch(Exception e){System.out.println(e.getMessage());return null;}    }    /**     * 查詢學生為某門課程提交的全部作業答案     * @param sourseid     * @param stuentid     * @return     */public ArrayList getAllHomeworkCommitBystu(String sourseid,String stuentid){     Connection conn=null;     Statement st=null;     ResultSet rs=null;     String sql ="select * from t_homework where course_code='"+sourseid+"' and type=2 and user_id='"+stuentid+"'";     ArrayList al=new ArrayList();     try{       DataBase ds = new DataBase();       conn = ds.conn;       st = conn.createStatement();       rs = st.executeQuery(sql);       while (rs.next()) {          homework cs=new homework();          cs.setid(rs.getInt(1));          cs.settitle(rs.getString(2));          cs.setlink(rs.getString(3));          cs.setdate(rs.getString(4));          cs.settype(rs.getString(5));          cs.setcourse_code(rs.getString(6));          cs.setuser_id(rs.getString(7));          cs.setstatus(rs.getString(8));          al.add(cs);       }       return al;     }catch(Exception e){System.out.println(e.getMessage());return null;}    }    /**     * 添加作業 老師發布的作業 或者學生為作業提交的答案     * @param rs     */    public void addHomework(homework rs)      {        Connection conn=null;       Statement st=null;       String sql="insert into t_homework(title,link,date,type,course_code,user_id)values("+                  " '"+rs.gettitle()+"',"+                  " '"+rs.getlink()+"',"+                  " getdate(),"+                  " '"+rs.gettype()+"',"+                  " '"+rs.getcourse_code()+"',"+                  " '"+rs.getuser_id()+"')";              System.out.println(sql);       try{         DataBase ds = new DataBase();         conn = ds.conn;         st = conn.createStatement();         st.executeUpdate(sql);       }catch(Exception e){System.out.println(e.getMessage());return ;}      }      /**       * 老師刪除已發布作業       * @param id       */      public void delHomeWork(String id)      {        Connection conn=null;      Statement st=null;      String sql="delete from t_homework where id='"+id+"'";             System.out.println(sql);      try{        DataBase ds = new DataBase();        conn = ds.conn;        st = conn.createStatement();        st.executeUpdate(sql);      }catch(Exception e){System.out.println(e.getMessage());return ;}      }      /**       * 學生提交答案 當老師閱覽過后 置狀態位為2       * @param id       */      public static void  updateHomeWorkSta(String id)           {             Connection conn=null;           Statement st=null;           String sql="update  t_homework set status='2' where id='"+id+"'";                  System.out.println(sql);           try{             DataBase ds = new DataBase();             conn = ds.conn;             st = conn.createStatement();             st.executeUpdate(sql);           }catch(Exception e){System.out.println(e.getMessage());return ;}           }}