求帮忙

package delu1805;

import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class SD {
JFrame jf=new JFrame("跳转界面");
@SuppressWarnings("unused")
public void init(){
jf.setSize(200, 200);
jf.setLocation(300, 300);
jf.setVisible(true);
JFrame jf=new JFrame("二手车估价软件");
JPanel p1=new JPanel();
JPanel p2=new JPanel();
JPanel p3=new JPanel();
JPanel p4=new JPanel();
JPanel p5=new JPanel();
JPanel p6=new JPanel();
JLabel l1=new JLabel("买入价格（万）");
TextField t1 = new TextField(10);
JLabel l2=new JLabel("购买时间");
JComboBox<String> jcb1=new JComboBox<String>();
jcb1.addItem("2011");
jcb1.addItem("2012");
jcb1.addItem("2013");
jcb1.addItem("2014");
jcb1.addItem("2015");
jcb1.addItem("2016");
jcb1.addItem("2017");
jcb1.addItem("2018");
jcb1.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
jcb1.getSelectedItem();
}
});
JLabel l3=new JLabel("行驶里程（万公里）");
TextField t3 = new TextField(10);
JLabel l4=new JLabel("卖出时间");
JComboBox<String> jcb2=new JComboBox<String>();
jcb2.addItem("2019");
jcb2.addItem("2020");
jcb2.addItem("2021");
jcb2.addItem("2022");
jcb2.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
jcb2.getSelectedItem();
}
});
}
}
运行不出来怎末办