嗨我真的需要帮助我的程序，我已经搜索了高低的解决方案，但似乎无法找到我正在寻找的。
我正在创建一个程序，用户在其中添加桌面，为其输入各种信息，然后将其添加到数组列表中。
以下是代码：
说明：
Scanner scan = new Scanner(System.in);
String input;
boolean looper = true;
DecimalFormat f = new DecimalFormat("#.00");
ArrayList<Desktop> desktopList = new ArrayList<>();
ArrayList<Laptop> laptopList = new ArrayList<>();
while (looper) {
System.out.println("");
System.out.println("******************* Artificial Intelligence Co. *************************");
System.out.println("1. Add Information for new Desktop");
System.out.println("2. Add Information for new Laptop");
System.out.println("3. Display all computer information");
System.out.println("4. Quit");
System.out.println("5. Credits");
System.out.println("*************************************************************************");
转换声明和案例1：
switch (input) {
case "1":
System.out.println("");
System.out.println("=========================================================================");
System.out.println("Information for new Desktop");
System.out.println("=========================================================================");
Desktop xx = new Desktop();
boolean loop = true;
while (loop) {
System.out.print("What is the Computer ID: ");
xx.setComputerID(scan.nextLine().toUpperCase());
if ((xx.getComputerID().startsWith("D")) && (xx.getComputerID().length() == 4)) {
loop = false;
} else {
System.out.println("Computer ID should start with a letter \"D\". and have 4 characters.");
System.out.println("");
}
}
loop = true;
while (loop) {
System.out.print("What is the Processor Speed: ");
xx.setCPUspeed(scan.nextLine().toUpperCase());
try {
if (StringisDouble(xx.getCPUspeed().substring(0, (xx.getCPUspeed().length() - 2))) ||
StringisDouble(xx.getCPUspeed().substring(0, (xx.getCPUspeed().length() - 3)))) { //checks the value before GHZ or HZ if its a double
if (xx.getCPUspeed().endsWith("GHZ") || xx.getCPUspeed().endsWith("HZ")) {
loop = false;
} else {
System.out.println("CPU Speed input should end with \"GHZ\" or \"HZ\".");
System.out.println("");
}
} else {
System.out.println("CPU Speed input should contain a decimal or number followed by a \"GHZ\" or a \"HZ\".");
System.out.println("");
}
} catch (StringIndexOutOfBoundsException e) {
System.out.println("CPU Speed input should contain a decimal or number followed by a \"GHZ\" or a \"HZ\".");
System.out.println("");
}
}
loop = true;
while (loop) {
System.out.print("What is the RAM: ");
xx.setRAM(scan.nextLine().toUpperCase());
try {
if (StringisInteger(xx.getRAM().substring(0, (xx.getRAM().length() - 2)))) { //checks the value if it is numeric and ending with GB or MB
if (xx.getRAM().endsWith("GB") || xx.getRAM().endsWith("MB")) {
loop = false;
} else {
System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\".");
System.out.println("");
}
} else {
System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\".");
System.out.println("");
}
} catch (StringIndexOutOfBoundsException e) {
System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\".");
System.out.println("");
}
}
loop = true;
while (loop) {
System.out.print("What is the Harddisk size: ");
xx.setHarddisk(scan.nextLine().toUpperCase());
try {
if (StringisInteger(xx.getHarddisk().substring(0, (xx.getHarddisk().length() - 2)))) { //checks the value if it is numeric and ending with GB or MB
if (xx.getHarddisk().endsWith("GB") || xx.getHarddisk().endsWith("TB")) {
loop = false;
} else {
System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\".");
System.out.println("");
}
} else {
System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\".");
System.out.println("");
}
} catch (StringIndexOutOfBoundsException e) {
System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\".");
System.out.println("");
}
}
loop = true;
while (loop) {
System.out.print("What is the Monitor: ");
xx.setMonitor(scan.nextLine().toUpperCase());
if (xx.getMonitor().equals("CRT") || xx.getMonitor().equals("LCD")) {
loop = false;
} else {
System.out.println("Please enter in CRT or LCD only.");
System.out.println("");
}
}
loop = true;
while (loop) {
try {
System.out.print("What is the price: $");
xx.setPrice(Double.parseDouble(scan.nextLine()));
loop = false;
} catch (NumberFormatException e) {
System.out.println("Price input should be numeric.");
System.out.println("");
}
}
desktopList.add(xx);
System.out.println("Information successfully added.");
System.out.println("");
System.out.println("");
break;
案例3，用户可以看到他/她输入的内容：
case "3":
int DesktopCounter = 1;
int LaptopCounter = 1;
System.out.println("");
if (desktopList.isEmpty()) {
System.out.println("No desktop added!");
System.out.println("");
} else {
for (int i = 0; i < desktopList.size(); i++) {
System.out.println("");
System.out.println("Desktop " + DesktopCounter);
System.out.println("Computer ID: " + desktopList.get(i).getComputerID());
System.out.println("Processor Speed: " + desktopList.get(i).getCPUspeed());
System.out.println("RAM: " + desktopList.get(i).getRAM());
System.out.println("Harddisk:" + desktopList.get(i).getHarddisk());
System.out.println("Monitor: " + desktopList.get(i).getMonitor());
System.out.println("Price: $" + f.format(desktopList.get(i).getPrice()));
DesktopCounter++;
}
}
break;
桌面类：
public class Desktop extends Computer //Child class of Computer
{
private static String Monitor;
public Desktop()
{
ComputerID = "-- No ID specified --";
CPUspeed = "-- No processor speed specified --";
RAM = "-- No RAM specified-";
Harddisk = "-- No Harddisk size specified --";
Monitor = "-- No Monitor specified --";
Price = 0.0;
}
//Setters and Getters
public String getMonitor()
{
return Monitor;
}
public void setMonitor(String monitor)
{
Monitor = monitor;
}
}
电脑课程：
public class Computer //Parent class
{
protected static String ComputerID;
protected static String CPUspeed;
protected static String RAM;
protected static String Harddisk;
protected static double Price;
public Computer() //Initializer
{
ComputerID = "-- No ID specified --";
CPUspeed = "-- No processor speed specified --";
RAM = "-- No amount RAM specified-";
Harddisk = "-- No Harddisk size specified --";
Price = 0.0;
}
public Computer(String computerID, String cpuspeed, String ram, String harddisk, double price) {
ComputerID = computerID;
CPUspeed = cpuspeed;
RAM = ram;
Harddisk = harddisk;
Price = price;
}
//Getters and Setters
public String getComputerID() {
return ComputerID;
}
public void setComputerID(String computerID) {
ComputerID = computerID;
}
public String getCPUspeed() {
return CPUspeed;
}
public void setCPUspeed(String cpuspeed) {
CPUspeed = cpuspeed;
}
public String getRAM() {
return RAM;
}
public void setRAM(String ram) {
RAM = ram;
}
public String getHarddisk() {
return Harddisk;
}
public void setHarddisk(String harddisk) {
Harddisk = harddisk;
}
public double getPrice() {
return Price;
}
public void setPrice(double price) {
Price = price;
}
//End of getters and setters
}
现在说如果我使用案例1添加一个桌面，并输入以下信息：
然后继续添加另一个桌面：
当我使用案例3代码块显示信息时，它输出：
当右侧时，桌面1应显示其自己的唯一属性。
我将不胜感激。
编辑：我通过使变量非静态来解决这个问题。
答案 0 :(得分：0)
更新
您的Desktop，Computer和Laptop课程中的字段不应为 static 。更改这些字段：
protected static String ComputerID;
protected static String CPUspeed;
protected static String RAM;
protected static String Harddisk;
protected static double Price;
到
protected String ComputerID;
protected String CPUspeed;
protected String RAM;
protected String Harddisk;
protected double Price;
静态字段对于类的每个对象都是相同的。因此，如果您有多个桌面并且您声明价格为静态，则所有桌面将共享相同的价格字段。这不是你想要的，显然所有桌面都有另一个价格。
同时更改
private static String Monitor;
到
private String Monitor;
您确实希望每台计算机都有一台独立的显示器，而不是为所有计算机共享同一台显示器。
旧回答
这里的代码运行完美，所以必须有一些缺失的信息：问题必须出现在你没有发布的代码的某些部分：
******************* Artificial Intelligence Co. *************************
1. Add Information for new Desktop
2. Add Information for new Laptop
3. Display all computer information
4. Quit
5. Credits
*************************************************************************
3
Desktop 1
Computer ID: D123
Processor Speed: 2GHZ
RAM: 2GB
Harddisk:1TB
Monitor: CRT
Price: $100.00
Desktop 2
Computer ID: D002
Processor Speed: 2GHZ
RAM: 16GB
Harddisk:2TB
Monitor: CRT
Price: $500.00
一些想法：
Desktop类，如果Desktop类中的字段被声明为静态，那将解释结果，确保它们不被声明为静态Desktop xx = new Desktop();不在上述代码中的case语句中desktopList.get(i)或desktopList.get(0)，则执行desktopList.get(someVariableThatIsAlwaysZero)你将始终打印相同的结果。使用新的foreach语法更安全：for (Desktop desktop : desktopList){ ... } 我会告诉你我的版本，你可能想比较一下：
public static void main(String args[]) {
Scanner scan = new Scanner(System.in);
String input;
boolean looper = true;
DecimalFormat f = new DecimalFormat("#.00");
ArrayList<Desktop> desktopList = new ArrayList<>();
ArrayList<Laptop> laptopList = new ArrayList<>();
while (looper) {
System.out.println("");
System.out.println("******************* Artificial Intelligence Co. *************************");
System.out.println("1. Add Information for new Desktop");
System.out.println("2. Add Information for new Laptop");
System.out.println("3. Display all computer information");
System.out.println("4. Quit");
System.out.println("5. Credits");
System.out.println("*************************************************************************");
input = scan.nextLine();
switch (input) {
case "1":
System.out.println("");
System.out.println("=========================================================================");
System.out.println("Information for new Desktop");
System.out.println("=========================================================================");
Desktop xx = new Desktop();
boolean loop = true;
while (loop) {
System.out.print("What is the Computer ID: ");
xx.setComputerID(scan.nextLine().toUpperCase());
if ((xx.getComputerID().startsWith("D")) && (xx.getComputerID().length() == 4)) {
loop = false;
} else {
System.out.println("Computer ID should start with a letter \"D\". and have 4 characters.");
System.out.println("");
}
}
loop = true;
while (loop) {
System.out.print("What is the Processor Speed: ");
xx.setCPUspeed(scan.nextLine().toUpperCase());
try {
if (StringisDouble(xx.getCPUspeed().substring(0, (xx.getCPUspeed().length() - 2))) ||
StringisDouble(xx.getCPUspeed().substring(0, (xx.getCPUspeed().length() - 3)))) { //checks the value before GHZ or HZ if its a double
if (xx.getCPUspeed().endsWith("GHZ") || xx.getCPUspeed().endsWith("HZ")) {
loop = false;
} else {
System.out.println("CPU Speed input should end with \"GHZ\" or \"HZ\".");
System.out.println("");
}
} else {
System.out.println("CPU Speed input should contain a decimal or number followed by a \"GHZ\" or a \"HZ\".");
System.out.println("");
}
} catch (StringIndexOutOfBoundsException e) {
System.out.println("CPU Speed input should contain a decimal or number followed by a \"GHZ\" or a \"HZ\".");
System.out.println("");
}
}
loop = true;
while (loop) {
System.out.print("What is the RAM: ");
xx.setRAM(scan.nextLine().toUpperCase());
try {
if (StringisInteger(xx.getRAM().substring(0, (xx.getRAM().length() - 2)))) { //checks the value if it is numeric and ending with GB or MB
if (xx.getRAM().endsWith("GB") || xx.getRAM().endsWith("MB")) {
loop = false;
} else {
System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\".");
System.out.println("");
}
} else {
System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\".");
System.out.println("");
}
} catch (StringIndexOutOfBoundsException e) {
System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\".");
System.out.println("");
}
}
loop = true;
while (loop) {
System.out.print("What is the Harddisk size: ");
xx.setHarddisk(scan.nextLine().toUpperCase());
try {
if (StringisInteger(xx.getHarddisk().substring(0, (xx.getHarddisk().length() - 2)))) { //checks the value if it is numeric and ending with GB or MB
if (xx.getHarddisk().endsWith("GB") || xx.getHarddisk().endsWith("TB")) {
loop = false;
} else {
System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\".");
System.out.println("");
}
} else {
System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\".");
System.out.println("");
}
} catch (StringIndexOutOfBoundsException e) {
System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\".");
System.out.println("");
}
}
loop = true;
while (loop) {
System.out.print("What is the Monitor: ");
xx.setMonitor(scan.nextLine().toUpperCase());
if (xx.getMonitor().equals("CRT") || xx.getMonitor().equals("LCD")) {
loop = false;
} else {
System.out.println("Please enter in CRT or LCD only.");
System.out.println("");
}
}
loop = true;
while (loop) {
try {
System.out.print("What is the price: $");
xx.setPrice(Double.parseDouble(scan.nextLine()));
loop = false;
} catch (NumberFormatException e) {
System.out.println("Price input should be numeric.");
System.out.println("");
}
}
desktopList.add(xx);
System.out.println("Information successfully added.");
System.out.println("");
System.out.println("");
break;
case "3":
int DesktopCounter = 1;
int LaptopCounter = 1;
System.out.println("");
if (desktopList.isEmpty()) {
System.out.println("No desktop added!");
System.out.println("");
} else {
for (int i = 0; i < desktopList.size(); i++) {
System.out.println("");
System.out.println("Desktop " + DesktopCounter);
System.out.println("Computer ID: " + desktopList.get(i).getComputerID());
System.out.println("Processor Speed: " + desktopList.get(i).getCPUspeed());
System.out.println("RAM: " + desktopList.get(i).getRAM());
System.out.println("Harddisk:" + desktopList.get(i).getHarddisk());
System.out.println("Monitor: " + desktopList.get(i).getMonitor());
System.out.println("Price: $" + f.format(desktopList.get(i).getPrice()));
DesktopCounter++;
}
}
break;
}
}
}
private static boolean StringisInteger(String substring) {return true;}
private static boolean StringisDouble(String substring) { return true; }
My Desktop类看起来像这样：
@Data
public class Desktop {
private double price;
private String computerID;
private String CPUspeed;
private String RAM;
private String harddisk;
private String monitor;
}
其中@Data是生成setter和getter的Lombok注释。如您所见，这些字段不是静态的。