It’s really not difficult to make one billion. If you don’t believe me, look at the code below

  private void ComputeActionPerformed(java.awt.event.ActionEvent evt) {
    
                                            
        // TODO add your handling code here:
       if(Salary.getText().isEmpty()||Aim.getText().isEmpty()||Saving.getText().isEmpty()) {
    
    
             JOptionPane.showMessageDialog(rootPane,"战胜恐惧的最好办法就是面对恐惧，乖乖把信息填全"); return;
       }
        Double money=Double.parseDouble(Salary.getText());
       Double Target=Double.parseDouble(Aim.getText());
       Double saving=Double.parseDouble(Saving.getText());
       double a =saving;
       int numofyears=0; 
        do
        {
    
       int i=0;
            for(i=1;i<13;i++)
          saving=saving + saving*0.004+money;
          numofyears += 1;
           }while(saving < Target);
        Result.setText("你的目标"+Target+"元"+"\n"+"您现在已有资金："+a+"\n"+"需要"+numofyears +"年才可达到");
      
    }