java 获取主机IP

public class Chat extends JFrame {
public static JTextField jt;
public Chat(){
setLayout(new FlowLayout()));

setLocation(200, 200);
setSize(200, 200);
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
setVisible(true);
Container con=this.getContentPane();
JLabel title=new JLabel();
title.setText("get the local IP");
title.setLocation(50, 0);

JLabel tit=new JLabel("IP adress:");
tit.setLocation(0, 20);
JButton jba=new JButton("yes");
JButton jb2=new JButton("exit");
jt=new JTextField(10);
con.add(title);
con.add(tit);
con.add(jt);
con.add(jba);
con.add(jb2);
//button listenering
jba.addActionListener(new jbalistener());
jb2.addActionListener(new jblistener());
}
public static JTextField getJt() {
return jt;
}
public void setJt(JTextField jt) {
this.jt = jt;
}
public static void main(String args[]){
new Chat();
}
}