Java-list中两种不同的对象类型for each遍历时用Object类型，出现了乱码，这事什么意思

Question

public class cartil {

    private String owerid;
    private String type;
    private String buydate;
    private String cph;
    public String getOwerid() {
        return owerid;
    }
    public void setOwerid(String owerid) {
        this.owerid = owerid;
    }
    public String getType() {
        return type;
    }
    public void setType(String type) {
        this.type = type;
    }
    public String getBuydate() {
        return buydate;
    }
    public void setBuydate(String date) {
        this.buydate = date;
    }
    public String getCph() {
        return cph;
    }
    public void setCph(String cph) {
        this.cph = cph;
    }
    
}

public class person {

    private String hostname;
    private String hostage;
    private String hostid;
    private String hostaddress;
    public String getHostname() {
        return hostname;
    }
    public void setHostname(String hostname) {
        this.hostname = hostname;
    }
    public String getHostage() {
        return hostage;
    }
    public void setHostage(String hostage) {
        this.hostage = hostage;
    }
    public String getHostid() {
        return hostid;
    }
    public void setHostid(String hostid) {
        this.hostid = hostid;
    }
    public String getHostaddress() {
        return hostaddress;
    }
    public void setHostaddress(String hostaddress) {
        this.hostaddress = hostaddress;
    }
}

public List selectallbycph(String cph){
        List list=new ArrayList();
        conn=DBUtil.getconn();
        try {
            psmt=conn.prepareStatement("select * from modelcar inner join host on host.hostid=modelcar.owerid where cph=?");
            psmt.setString(1, cph);
            res=psmt.executeQuery();
            if(res.next()){
                //System.out.print("jsafhjafjas");
                cartil c=new cartil();
                 person p=new person();
                c.setBuydate(res.getString("buydate"));
                c.setCph(res.getString("cph"));
                c.setOwerid(res.getString("owerid"));
                c.setType(res.getString("type"));
                p.setHostid(res.getString("hostid"));
                p.setHostname(res.getString("hostname"));
                p.setHostage(res.getString("hostage"));
                p.setHostaddress(res.getString("hostaddress"));
                list.add(c);
                list.add(p);
            }
            return list;
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try {
                conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return null;
    }

 
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
        // TODO add your handling code here:
        DefaultTableModel dtm = new DefaultTableModel();
        dtm.addColumn("车牌号");
        dtm.addColumn("证件号");
        dtm.addColumn("车型");
        dtm.addColumn("购买日期");
        dtm.addColumn("用户身份证号");
        dtm.addColumn("用户姓名");
        dtm.addColumn("用户年龄");
        dtm.addColumn("用户地址");
        cardao cd = new cardao();
        List c = (List) cd.selectallbycph(jTextField1.getText());
        Vector v = new Vector();
        for(Object s :c){
            v.add(s);
        }
        //v.add(c);
        dtm.addRow(v);
        jTable1.setModel(dtm);

        this.initable();

    }

Answer 1

18行断点试一下,从list取出来的Ojbect是Object类型
要或者你试试instanceof判断下类型?

Answer 2

重新看了一下问题, 传入的是一个对象实例, 所以给出dao.person@b6c6a2 这种. 这个不叫乱码啊...
java.lang.Object.toString():

public String toString() {
return getClass().getName() + "@" + Integer.toHexString(hashCode());
}

如果想得到有意义的数据, 覆写Object的toString()方法.