如何在Java中设置背景色

Question

Hey guys I'm actually new in java programming.Where can I put the line of code for background color.Because when I put a jpanel with a color yellow in main method .The setting of background color in jframe works but the jlabel,jtextfield and jbutton are now missing..everything is just yellow.

package testpath;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.io.*;

public class Testpath extends JFrame {

        JLabel label;
        JTextField tf;
        JButton button;

 public Testpath(){
       setLayout(new FlowLayout());

       label= new JLabel("Enter First Name");
       add(label);

       tf=new JTextField(10);
       add(tf);

       button=new JButton("Log In");
       add(button);

       event e=new event();
     button.addActionListener(e);
  }

 public class event implements ActionListener{
     public void actionPerformed(ActionEvent e){
         try{
             String word=tf.getText();
             FileWriter stream= new     FileWriter("C://Users//Keyboard//Desktop//file.txt");
             BufferedWriter out=new   BufferedWriter(stream);
             out.write(word);
         }catch (Exception ex){}
     }
 }


public static void main(String[] args) {
    Testpath gui=new Testpath();
    gui.setLocationRelativeTo(null);
    gui.setVisible(true);
    gui.setSize(400,250);
    gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  

}

}

Answer 1

Change the jPanel Backgroundcolor: jPanel.setBackground(Color.YELLOW); And then you need to set jPanel.setOpaque(false); because default it´s transparent. Other components doesn´t change their color if you just add this on a specific component.

Answer 2

Try to develop using netbeans. It has all the features to decorate using the IDE itself. Then you can see the code also in the source.