所以我试图将存储在一个类Liquor的ArrayList中的数据显示到另一个类Bar中 . ArrayList保存5个字符串(酒的名称)和5个整数(每种酒的量) . 当我运行代码来显示信息时,我得到一个很长的错误:
barinventory.BarInv.jButtonDisplayActionPerformed(BarInv.java:355)at barinventory.BarInv.access $ 200(BarInv.java:8)at barinventory.BarInv $ 3.actionPerformed中的线程“AWT-EventQueue-0”java.lang.NullPointerException中的异常(BarInv.java:219)javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)at javax.swing.AbstractButton $ Handler.actionPerformed(AbstractButton.java:2348)at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel . java:402)at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)at java.awt.Component.processMouseEvent(Component.java) :6535)在javax.swing.JComponent.processMouseEvent(JComponent.java:3324)java.awt.Component.processEvent(Component.java:6300)java.awt.Container.processEvent(Container.java:2236)at java .awt.Component.dispatchEventImpl(Component.java:4891)at java.awt.Container.dispatchEventImpl(Containe) r.java:2294)java.awt.Light上的java.awt.Component.dispatchEvent(Component.java:4713)java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525) )java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)at java.awt.Container.dispatchEventImpl(Container.java:2280)at java.awt.Window.dispatchEventImpl(Window.java:2750)at java.awt .Component.dispatchEvent(Component.java:4713)位于java.awt.EventQueue.access上的java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758),java.awt.EventQueue $ 3中的$ 500(EventQueue.java:97) . 在java.security.ProtectionDomain的Java.security.AccessController.doPrivileged(Native Method)java.awt.EventQueue $ 3.run(EventQueue.java:703)上运行(EventQueue.java:709)$ JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java) :76)at java.security.ProtectionDomain $ JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)at java.awt.EventQueue $ 4.run(EventQueue.java:731) at java.awt.EventQueue $ 4.run(EventQueue.java:729)at java.security.AutorController.doPrivileged(Native Method)at java.security.ProtectionDomain $ JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)at java.awt . 位于java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)的java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)中的EventQueue.dispatchEvent(EventQueue.java:728),位于java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread) .java:105)at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) BUILD STOPPED(总时间:12秒)
我的酒类:
final class Liquor
{
//String[] liquor = {"Vodka", "Whiskey", "Rum", "Gin", "Brandy"};
private final String vodka, whiskey, rum, gin, brandy;
private final int vCount, wCount, rCount, gCount, bCount;
ArrayList<Liquor> liquors = new ArrayList<>();
// public Liquor(ArrayList<Liquor> liquors)
// {
//
// this.vodka = "Vodka";
// this.whiskey = "Whiskey";
// this.rum = "Rum";
// this.gin = "Gin";
// this.brandy = "Brandy";
// this.vCount = getVC();
// this.wCount = getWC();
// this.rCount = getRC();
// this.gCount = getGC();
// this.bCount = getBC();
// } was trying to pass it through the ArrayList itself... Didn't work.
//The stock number kept being read in as 0.
public Liquor(String vodka, String whiskey, String rum, String gin,
String brandy, int v, int w, int r, int g, int b)
{
this.vodka = vodka;
this.whiskey = whiskey;
this.rum = rum;
this.gin = gin;
this.brandy = brandy;
this.vCount = v;
this.wCount = w;
this.rCount = r;
this.gCount = g;
this.bCount = b;
}
public String getV()
{
return vodka;
}
public String getW()
{
return whiskey;
}
public String getR()
{
return rum;
}
public String getG()
{
return gin;
}
public String getB()
{
return brandy;
}
public int getVC()
{
return vCount;
}
public int getWC()
{
return wCount;
}
public int getRC()
{
return rCount;
}
public int getGC()
{
return gCount;
}
public int getBC()
{
return bCount;
}
@Override
public String toString()
{
return "\nLiquor currently in stock:\n" + vodka + ": " + vCount + "\n" +
whiskey + ": " + wCount + "\n" + rum + ": " + rCount + "\n" +
gin + ": " + gCount + "\n" + brandy + ": " + bCount;
}
}
我的酒吧班:
class Bar
{
private final String barLoc, barName;
private final boolean music, food;
//ArrayList<Liquor> liquor;
public Bar(String l, String n, boolean m, boolean f)
{
this.barLoc = l;
this.barName = n;
this.music = m;
this.food = f;
}
//ArrayList<Liquor> liquor = new ArrayList<>();
private Liquor liquor;
public Liquor getLiquor()
{
return liquor;
}
@Override
public String toString()
{
return "The " + barLoc + " bar is named: " + barName + "\nLive music: "
+ music + "\nFood Service: " + food;
}
}
用于显示的代码:
for(int i=0; i<bars.size(); i++)
{
jTextAreaDisplay.append(jTextAreaDisplay.getText()
+ bars.get(i).toString() + bars.get(i).getLiquor().toString()
+ "\n\n");
}
我认为这个问题与初始化我的Bar类中的 private Liquor liquor;
有关,我认为它是正确的 . 任何帮助将不胜感激!
示例运行:
(barLocation)栏名为:(barName)现场音乐:(真或假)食品服务:(真或假)现有的酒:伏特加:(库存量)威士忌:(库存量)朗姆酒:(库存量)杜松子酒:(库存量)白兰地:(库存量)
2 回答
好吧,据我所知,你从来没有初始化酒 .
初始化看起来像这样
我没有达到创造一个含有更多液体(伏特加等)的单一酒对象的目的 . 但也许你有理由 . 如果没有,那么我会设计不同的酒,因为你所做的并不像现实 . 通常,类Liquor应该具有这样的属性:
然后我会在你的栏中创建一个Liquors的ArrayList并用一些值填充它 .
现在我的fill方法显然需要你的Liquid类有一个带有2个参数的构造函数(String name,int alcohol)
您尚未初始化Liquor对象 . 请尝试以下语句