移动物体并同时跳跃（键盘输入）

Question

  

我正在使用的Character类读取键码并进行移动   基于此。它跳跃并移动，但问题是它没有   正确地跳跃和移动。有没有办法解决   此

import java.awt.*;

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

public class Character 
{
    int c_posX, c_posY; // x and y positions
    int c_velx; // velocity for x
    public int gravity = 1, c_speedX = 20, c_diam = 25; 
    public int c_speedY = 26; // the initial jumping speed.
    public Character(int c_posX, int c_posY)

    {
        this.c_posX = c_posX;
        this.c_posY = c_posY;
        c_velx = 0;
    }

    public int getCposX() 
    {
        return c_posX;
    }

    // Create a method to check the Y coordinate of the player
    public int getCposY() 
    {
        return c_posY;
    }

    // Create a method to check the width of the player
    public int getCdiam() 
    {
        return c_diam;
    }

    public void updateCY() // if the character is jumping, then continue to add gravity
        {
      if (ifJumping() == true) {
            c_speedY = c_speedY - gravity;
            c_posY = c_posY - c_speedY;
        }

    }
public void keyPressed(int keycode) 
{
    if (keycode == 37) // if the user presses the left arrow
    {
        c_velx = -c_speedX;
    }
    if (keycode == 39) 
    {
        c_velx = c_speedX; // if the user presses the right arrow
    }
    if (keycode == 38) 
    {
        initialize(keycode); // if the user presses the up arrow,check if it can jump
    }

}

public void updateCX() // update the x position of the character
{
    c_posX += c_velx;
    c_velx = 0;
}

public int returnKey(int keycode)
{
    return keycode;
}

public void stopJumping()  // stop jumping once the character reaches a certain velocity
{
    if (DoneJumping() == true) 
    {
        c_posY = 0;
    }
}

public boolean ifJumping() // check if the character is jumping
{
    if (c_speedY <= 25 & DoneJumping() == false) {
        return true;
    }
    return false;
}

public boolean DoneJumping() // return true if the character's y velocity is less than -30.
{
    if (c_speedY < (-30)) 
    {
        return true;
    }
    return false;
}

public void initialize(int keycode) 
{
    if (ifJumping() == false) // start jumping if it is not jumping 
    {
        c_speedY = 25;
        c_posY = c_posY - c_speedY;

    }
}

}