JAVA 利用反射机制查询数据库返回相应对象-蒲公英云

JAVA 利用反射机制查询数据库返回相应对象

傷城~ 2022-08-25 11:53 221阅读 0赞

public static void main(String [] rags){
        SQLHepler SH=new SQLHepler();
        String  sql="select * from DB_Image";
        String [] p={"107"};
        try {
         List<Object> c=SH.excuteSelectSQL(sql, null, DBImage.class);
          for (Object o:c) {
              DBImage cam=(DBImage) o;
              System.out.println(cam.getImageID()+" "+cam.getImageRealPath());
         }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
    }
    private   List<String> getAllMethods(Class c){
        List<String> allMendth=new ArrayList<String>();
        Field [] f=c.getDeclaredFields();
        for(int i=0;i<f.length;i++){
            String m="set";
            m+=f[i].getName();
            allMendth.add(m);
        }
        return allMendth;
    }
    public List<Object> excuteSelectSQL(String sql,String [] parmates,Class clazz) throws Exception{
             List<Object> all=new ArrayList<Object>();
             Conn conn=new Conn();
             this.con=conn.getConn();
             this.ps=con.prepareStatement(sql);
             if(parmates!=null && !parmates.equals("")){
                   int index=1;
                   for(String s:parmates){
                       this.ps.setString(index, s);
                       index++;
                   }
              }
             this.rs=this.ps.executeQuery();
             while(rs.next()){
                    Object o = clazz.newInstance();
                    List<String> allMethods=getAllMethods(clazz);
                    int index=1;
                    for(String s:allMethods){
                        clazz.getDeclaredMethod(s, String.class).invoke(o, rs.getString(index));
                        index++;
                    }
                    all.add(o);
             }
            return all;
    }