Java 在服务器和客户端之间获取和发送数据

我们正在制作一个六人多人游戏，我负责一个网络课程。游戏采用了流畅的2D。游戏中有实体（代码如下所示）

这是战斗代码，其中包含主要的游戏代码，代码目前尚未完成，只有移动：

 package Game;

import java.util.ArrayList;

import org.lwjgl.input.*;
import org.newdawn.slick.*;
import org.newdawn.slick.geom.Rectangle;
import org.newdawn.slick.state.*;

public class Battle extends BasicGameState {

    private ArrayList<Entity> entities = new ArrayList<Entity>();
    private Hero player;
    private Image background;
    private int midScreen, ground;

    public void init(GameContainer gc, StateBasedGame sbg) throws SlickException{
        gc.setVSync(true);
        player = new Ares();
        player.setCurrent(player.getStanding());
        entities.add(player);
        background = new Image("res/Background.png");
        midScreen = 800;
        ground = 625;
    }


    public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException{
        g.translate((float)-player.getLocationX() + midScreen, (float)-player.getLocationY() + ground);
        background.draw(0, -920);
        for(int i = 0; i < entities.size(); i++)
            entities.get(i).getCurrent().draw((float)entities.get(i).getLocationX(), (float)entities.get(i).getLocationY());
    }

    public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException {
            player.getCurrent().update(delta); // ensures
            Input kb = gc.getInput();

            if (kb.isKeyDown(Input.KEY_SPACE) && player.getGrounded()) {
                player.setGrounded(false);
                player.setVelocity(7);
               player.setLocation(player.getLocationX(), player.getLocationY() - player.getVelocity());
                player.setCurrent(player.getStanding());
            }
            else if (kb.isKeyDown(Input.KEY_A) && player.getLocationX() > 800) {
                player.setLocation(player.getLocationX() - player.getSpeed() * delta, player.getLocationY());
                if(player.grounded)
                    player.setCurrent(player.getRight());
            }
            else if (kb.isKeyDown(Input.KEY_D) && player.getLocationX() < 8580) {
                player.setLocation(player.getLocationX() + player.getSpeed() * delta, player.getLocationY());
                if(player.grounded)
                    player.setCurrent(player.getRight());
            }
            else
                player.setCurrent(player.getStanding());

            if (Math.abs(player.getLocationY() - ground) < .01)
                player.setGrounded(true);
            if (player.getGrounded() == false) {
                player.setVelocity(player.getVelocity() - player.getGravity());
                player.setLocation(player.getLocationX(), player.getLocationY() - player.getVelocity());
            }  
    }    

    public int getID(){
        return 1;
    }
}

打包游戏；
导入java.util.ArrayList；
导入组织lwjgl.input.*；
导入org.newdawn.slick.*；
导入org.newdawn.slick.geom.Rectangle；
导入org.newdawn.slick.state.*；
公共阶级斗争扩展到基本美国国家{
私有ArrayList实体=新ArrayList（）；
私人英雄玩家；
私有图像背景；
私人中屏，地面；
public void init（GameContainer gc，StateBasedGame sbg）引发异常{
gc.setVSync（真）；
玩家=新战神（）；
player.setCurrent（player.getStanding（））；
实体。添加（玩家）；
背景=新图像（“res/background.png”）；
中屏=800；
接地=625；
}
公共void呈现（GameContainer gc、StateBasedGame sbg、Graphics g）引发异常{
g、 翻译（（float）-player.getLocationX（）+屏幕中间，（float）-player.getLocationY（）+地面）；
背景图（0，-920）；
对于（int i=0；i800）{
player.setLocation（player.getLocationX（）-player.getSpeed（）*delta，player.getLocationY（））；
如果（球员接地）
player.setCurrent（player.getRight（））；
}
else if（kb.isKeyDown（Input.KEY_D）和&player.getLocationX（）<8580）{
player.setLocation（player.getLocationX（）+player.getSpeed（）*delta，player.getLocationY（））；
如果（球员接地）
player.setCurrent（player.getRight（））；
}
其他的
player.setCurrent（player.getStanding（））；
if（Math.abs（player.getLocationY（）-ground）<.01）
player.setGrounded（true）；
if（player.getground（）==false）{
player.setVelocity（player.getVelocity（）-player.getGravity（））；
player.setLocation（player.getLocationX（），player.getLocationY（）-player.getVelocity（））；
}  
}    
公共int getID（）{
返回1；
}
}

我遇到的困难是创建一个服务器和客户端，从玩家那里获取输入，例如位置，谁选择了哪个玩家，等等。我想知道，如果在战斗中，当玩家对象被制作出来时，我如何能够获取对象的位置和其他特定属性，并将它们提供给其他计算机

注意：我正在用Java编写代码，并尝试使用TCP连接来编写代码。我对UDP持开放态度，如果你认为它可能更容易。只是给一个需要做什么的基本概述，也许有一点代码，不要简单地给我答案

    package Game;

import org.newdawn.slick.Animation;

public abstract class Hero extends Entity{

    static double gravity = 0.1;
    double velocity;
    int level;
    boolean disabled, grounded = true;

    public void setLevel(int i){
        level = i;
    }
    public void setVelocity(double d){
        velocity = d;
    }
    public void setDisabled(boolean b){
        disabled = b;
    }
    public void setGrounded(boolean b){
        grounded = b;
    }
    public int getLevel(){
        return level;
    }
    public double getVelocity(){
        return velocity;
    }
    public boolean getDisabled(){
        return disabled;
    }
    public boolean getGrounded(){
        return grounded;
    }
    public double getGravity(){
        return gravity;
    }

    public boolean isAlive(){
        if(getHealth() > 0)
            return true;
        return false;
    }

    public void attack(Entity gettingAttacked, Hero attacking) {
        gettingAttacked.setHealth(gettingAttacked.getHealth() - attacking.getDamage());
    }

    public boolean isReadyToRegenerate(long delta) {
        if(pastTime < 1 * 1000){
            pastTime += delta;
            return false;
        }
        else{
            pastTime = 0;
            return true;
        }
    }   

    public static void regenerate(Hero h, long delta){
        if(h.getHealth() >= 0 && h.getHealth() < h.getMaxHealth())
            if(h.isReadyToRegenerate(delta))
                h.setHealth(h.getHealth() + (h.getMaxHealth()) * 0.01);
    }
    public abstract void levelUp();
}

   package Game;

import org.newdawn.slick.Animation;
import org.newdawn.slick.SlickException;
import org.newdawn.slick.SpriteSheet;

public class Ares extends Hero {

    public Ares() throws SlickException {
        setHealth(500);
        setSpeed(0.4);
        setDamage(70);
        setLocation(850,625);
        setSprites(new Animation(new SpriteSheet("res/Ares.png", 191, 275), 200), new Animation(new SpriteSheet("res/AresWalk.png", 191, 275), 200));
    }

    public void levelUp() {
        level += 1;
        health *= 1.1;
        damage *= 1.1;
    }

    public double getAttackRange() {
        return 250;
    }

    public double maxHealth() {
        return 500;
    }

}

 package Game;

import java.util.ArrayList;

import org.lwjgl.input.*;
import org.newdawn.slick.*;
import org.newdawn.slick.geom.Rectangle;
import org.newdawn.slick.state.*;

public class Battle extends BasicGameState {

    private ArrayList<Entity> entities = new ArrayList<Entity>();
    private Hero player;
    private Image background;
    private int midScreen, ground;

    public void init(GameContainer gc, StateBasedGame sbg) throws SlickException{
        gc.setVSync(true);
        player = new Ares();
        player.setCurrent(player.getStanding());
        entities.add(player);
        background = new Image("res/Background.png");
        midScreen = 800;
        ground = 625;
    }


    public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException{
        g.translate((float)-player.getLocationX() + midScreen, (float)-player.getLocationY() + ground);
        background.draw(0, -920);
        for(int i = 0; i < entities.size(); i++)
            entities.get(i).getCurrent().draw((float)entities.get(i).getLocationX(), (float)entities.get(i).getLocationY());
    }

    public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException {
            player.getCurrent().update(delta); // ensures
            Input kb = gc.getInput();

            if (kb.isKeyDown(Input.KEY_SPACE) && player.getGrounded()) {
                player.setGrounded(false);
                player.setVelocity(7);
               player.setLocation(player.getLocationX(), player.getLocationY() - player.getVelocity());
                player.setCurrent(player.getStanding());
            }
            else if (kb.isKeyDown(Input.KEY_A) && player.getLocationX() > 800) {
                player.setLocation(player.getLocationX() - player.getSpeed() * delta, player.getLocationY());
                if(player.grounded)
                    player.setCurrent(player.getRight());
            }
            else if (kb.isKeyDown(Input.KEY_D) && player.getLocationX() < 8580) {
                player.setLocation(player.getLocationX() + player.getSpeed() * delta, player.getLocationY());
                if(player.grounded)
                    player.setCurrent(player.getRight());
            }
            else
                player.setCurrent(player.getStanding());

            if (Math.abs(player.getLocationY() - ground) < .01)
                player.setGrounded(true);
            if (player.getGrounded() == false) {
                player.setVelocity(player.getVelocity() - player.getGravity());
                player.setLocation(player.getLocationX(), player.getLocationY() - player.getVelocity());
            }  
    }    

    public int getID(){
        return 1;
    }
}