每日一算法4--将毫秒转化为日期

import java.awt.BorderLayout;
import java.awt.Frame;
import java.awt.TextArea;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.text.SimpleDateFormat;
import java.util.Date;


public class Day4 {


public static void main(String[] args) {
new ConvertLong2Date().launchFrame();
}


public static class ConvertLong2Date extends Frame {
TextField tf = new TextField();
TextArea ta = new TextArea();

//主要方法,将毫秒转为日期
public String convertL2D(long l) {
long _l = 0L;
Date _d = null;
SimpleDateFormat _sdf = null;
String _s = null;
_l = l;
_d = new Date(_l);
_sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
_s = _sdf.format(_d);
return _s;
}

//设置布局属性
public void launchFrame() {
setLocation(300, 300);
setSize(480, 320);
setResizable(false);
add(tf, BorderLayout.SOUTH);
add(ta, BorderLayout.NORTH);
pack();
tf.addActionListener(new tfActionListener());
this.setVisible(true);
this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
}

//添加监听
public class tfActionListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
long l = Long.parseLong(tf.getText());
ta.setText(new ConvertLong2Date().convertL2D(l));


tf.setText("");
}
}
}
}