How can I align labels and text fields added to a split pane?

Question

In the below code I want to align my labels and text fields.in the left Pane. I have tried using setBounds() and setLocation() methods but it does not work.

Here is my code:

package com.sample.GUI;

import java.awt.*;
import java.io.*;
import javax.swing.*;

class GUI extends JFrame 
{  

    public void GUI(){
        JPanel leftPan = new JPanel(); 
        JPanel rightPan = new JPanel();
        JSplitPane splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, leftPan,rightPan);
         
        JLabel l1,l2;  
        JTextField t1 = new JTextField();
        JTextField t2 = new JTextField();       
        JFilePicker filePicker = new JFilePicker("Select FIle", "Browse...");
        filePicker.setMode(JFilePicker.MODE_OPEN);
        String filePath = filePicker.getSelectedFilePath();
        rightPan.add(filePicker);
        l1=new JLabel("Label1");   
        l2=new JLabel("Label2");
        l2.setBounds(100,150, 100,30); 
        l2.setBounds(100,100, 100,30);  
        splitPane.setDividerLocation(0.6);
        splitPane.setDividerSize(1);
        getContentPane().setLayout(new GridBagLayout());
        getContentPane().add(splitPane, null);
        leftPan.add(l1);
        leftPan.add(l2);  
        leftPan.add(t1);
        leftPan.add(t2);
        setSize(700,500);  
        setTitle("GUI");
        setVisible(true); 
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);
   } 
}