试图存储变量中以前的值,然后进行更新,但它';它只是存储当前值?JAVA
我试图将一个数组对象(ao1)的值存储在另一个arraylist对象(ao2)中,然后修改ao1的值 然后我想比较这些值 然而,ao2(应该有旧的值)仍然会有像ao1一样的新值。为了使这更复杂一点,ao2每5秒通过一个定时器类随机改变一次。在一点上下文中,这是为了模拟股票市场。对于更复杂的问题,它涉及到Swing GUI的使用 这是我的代码(我添加了我认为相关的内容,在本例中,ao1将是“股票市场”,ao2将是“预股票市场”): StockGUI类 市场运动班试图存储变量中以前的值,然后进行更新,但它';它只是存储当前值?JAVA,java,swing,arraylist,timer,Java,Swing,Arraylist,Timer,我试图将一个数组对象(ao1)的值存储在另一个arraylist对象(ao2)中,然后修改ao1的值 然后我想比较这些值 然而,ao2(应该有旧的值)仍然会有像ao1一样的新值。为了使这更复杂一点,ao2每5秒通过一个定时器类随机改变一次。在一点上下文中,这是为了模拟股票市场。对于更复杂的问题,它涉及到Swing GUI的使用 这是我的代码(我添加了我认为相关的内容,在本例中,ao1将是“股票市场”,ao2将是“预股票市场”): StockGUI类 市场运动班 private Random rn
private Random rn1=new Random();
//确定是否使市场朝着积极方向(1)或消极方向(0)移动
私人机构1;
private ArrayList preStockList=new ArrayList();
//创建一个计时器,这样我就可以复制不断的市场运动
java.util.Timer Timer=新的java.util.Timer();
公共市场运动(市场){
getChangedMarket(市场);
}
公众街市(街市){
ArrayList listOfStocks=market.getStockList();
用于(库存:库存清单){
rand1=rn1.nextInt(2);
if(rand1==1){
market.piup(stock.getStockName().toString());
System.out.println(“当前库存上升”+Stock.getStockName());
}
否则{
market.pipDown(stock.getStockName().toString());
System.out.println(“当前股票下跌”+Stock.getStockName());
}
}
}
公共仓库预库存(市场){
for(Stock:market.getStockList()){
预库存清单。添加(库存);
}
}
公开无效getChangedMarket(市场股票市场){
//这个计时器允许我不断运行随机器,以确定市场应该向哪个方向移动
timer.schedule(新TimerTask()
{
@凌驾
公开募捐{
storePreStock(股票市场);
//rand1=rn1.nextInt(2);
证券市场;
}
}, 0, 5000);
}
公共ArrayList getPreStockList(){
返回预库存列表;
}
市场等级
私人股本1;
私人股本2;
私人股本3;
private ArrayList stockList=new ArrayList();
int[]可能性={0,1,1,1,1,1,2,2,2,3,3,4,4,5,5,5,6,7,8,9,9,10,11,12,1,1,1,2,2,3,3};
private int rnd=new Random().nextInt(可能性.length);
/**
*类市场对象的构造函数
*/
公开市场()
{
//初始化实例变量
股票1=新股(“英镑/美元”,1.2245,1.2244);
股票2=新股(“英镑/欧元”,1.3342,1.3341);
股票3=新股票(“欧元/美元”,1.0224,1.0223);
库存清单。添加(库存1);
库存清单。添加(库存2);
存货清单。添加(存货3);
}
公共void piup(字符串stockname){
//循环遍历ArrayList“stockList”中的每个项目,并根据MarketMovement.alterMarket()创建的输入更改其值
用于(库存:库存清单){
if(stock.getStockName().equals(stockname)){
//将增加值更改为随机数
double currentBuy=stock.getBuy();
double currentSell=stock.getSell();
股票.setBuy(四舍五入(当前买入+(0.0001*可能性[rnd]),4);
股票集合销售(四舍五入(当前卖出+(0.0001*可能性[rnd]),4);
}
}
}
公共void下拉列表(字符串stockname){
用于(库存:库存清单){
if(stock.getStockName().equals(stockname)){
//将增加值更改为随机数
double currentBuy=stock.getBuy();
double currentSell=stock.getSell();
股票.setBuy(四舍五入(当前买入-(0.0001*可能性[rnd]),4);
股票集合销售(四舍五入(当前卖出-(0.0001*可能性[rnd]),4);
}
}
}
也许当我将stockMarket中的值分配给preStockMarket变量时,它只是引用了地址而不是实际存储的值,因此不管怎样都会有新的值
抱歉,我还是Java新手。如果要复制
列表
请使用复制构造函数
List<Integer> oldList = new ArrayList<>();
List<Integer> newList = new ArrayList<>(oldList);
List oldList=new ArrayList();
List newList=newarraylist(oldList);
欢迎使用堆栈溢出!看起来您需要学习使用调试器。请随便吃点。如果您以后仍然有问题,请随时回来提供更多详细信息。我甚至不知道这个存在!我想这已经成功了-谢谢!
private Random rn1 = new Random();
//to determine whether to make the market move in a positive direction (1) or negative (0)
private int rand1;
private ArrayList<Stock> preStockList = new ArrayList();
//create a timer so that I can replicate constant market movement
java.util.Timer timer = new java.util.Timer();
public MarketMovement(Market market){
getChangedMarket(market);
}
public void alterMarket(Market market){
ArrayList<Stock> listOfStocks = market.getStockList();
for (Stock stock : listOfStocks){
rand1 = rn1.nextInt(2);
if (rand1 == 1){
market.pipUp(stock.getStockName().toString());
System.out.println("current Stock is up " + stock.getStockName());
}
else {
market.pipDown(stock.getStockName().toString());
System.out.println("current Stock is down " + stock.getStockName());
}
}
}
public void storePreStock(Market market){
for (Stock stock : market.getStockList()){
preStockList.add(stock);
}
}
public void getChangedMarket(Market stockMarket){
//This timer allows me to run a randomiser constantly to determine which direction the market should move
timer.schedule(new TimerTask()
{
@Override
public void run() {
storePreStock(stockMarket);
//rand1 = rn1.nextInt(2);
alterMarket(stockMarket);
}
}, 0, 5000);
}
public ArrayList<Stock> getPreStockList(){
return preStockList;
}
private Stock stock1;
private Stock stock2;
private Stock stock3;
private ArrayList<Stock> stockList = new ArrayList();
int[] possibility = {0,1,1,1,1,1,2,2,2,2,3,3,3,4,4,5,5,5,6,6,7,8,9,9,10,11,12,1,1,1,2,2,2,3,3,3};
private int rnd = new Random().nextInt(possibility.length);
/**
* Constructor for objects of class Market
*/
public Market()
{
// initialise instance variables
stock1 = new Stock("GBP/USD", 1.2245, 1.2244);
stock2 = new Stock("GBP/EUR", 1.3342, 1.3341);
stock3 = new Stock("EUR/USD", 1.0224, 1.0223);
stockList.add(stock1);
stockList.add(stock2);
stockList.add(stock3);
}
public void pipUp(String stockname){
//Loop through each item in the ArrayList "stockList" and change its value based on the input created from MarketMovement.alterMarket()
for (Stock stock : stockList){
if (stock.getStockName().equals(stockname)){
//change the increase value by a random number
double currentBuy = stock.getBuy();
double currentSell = stock.getSell();
stock.setBuy(round(currentBuy + (0.0001*possibility[rnd]), 4));
stock.setSell(round(currentSell + (0.0001*possibility[rnd]), 4));
}
}
}
public void pipDown(String stockname){
for (Stock stock : stockList){
if (stock.getStockName().equals(stockname)){
//change the increase value by a random number
double currentBuy = stock.getBuy();
double currentSell = stock.getSell();
stock.setBuy(round(currentBuy - (0.0001*possibility[rnd]), 4));
stock.setSell(round(currentSell - (0.0001*possibility[rnd]), 4));
}
}
}
List<Integer> oldList = new ArrayList<>();
List<Integer> newList = new ArrayList<>(oldList);