Question

我现在在JAVA学习命令行。我是初学者。我为我的项目编写了一个硬代码，但我不知道如何应用命令行。

public class SalesRep 

private String firstName;
private String lastName;
private String employeeID;
private double grossSales;
private double commissionRate;

public SalesRep(String[] args)
{
    if (args.length != 5)
        System.out.printf("Error");
    else
    {
        firstName = args[0];
        lastName = args[1];
        employeeID = args[2];
        grossSales = Double.parseDouble(args[3]);
        commissionRate = Double.parseDouble(args[4]);
    }
    if (grossSales < 0.0)
        throw new IllegalArgumentException
        ("Gross sale must be greater than or equal 0.0");
    if (commissionRate <= 0.0 || commissionRate >= 1.0)
        throw new IllegalArgumentException
        ("Comission rate must be in between 0.0 and 1.0");
}

public String getFirstName()
{
    return firstName;
}
public String getLastName()
{
    return lastName;
}
public String getEmployeeID()
{
    return employeeID;
}
public void setGrossSales(double grossSales)
{
    if (grossSales < 0.0)
        throw new IllegalArgumentException
        ("Gross sales must be greater than or equal 0.0");
    this.grossSales = grossSales;
}
public double getGrossSales()
{
    return grossSales;
}
public void setCommissionRate(double commissionRate)
{
    if (commissionRate <= 0.0 || commissionRate >= 1.0)
        throw new IllegalArgumentException
        ("Comission rate must be in between 0.0 and 1.0");
    this.commissionRate = commissionRate;
}
public double getCommissionRate()
{
    return commissionRate;
}
public double earnings()
{
    return getCommissionRate() * getGrossSales();
}
@Override
public String toString()
{
    return String.format("%s: %s %s%n%s: %s%n%s: %.2f%n%s: %.2f", 
            "Sale Representatives", firstName, lastName,
            "Employee ID", employeeID,
            "Gross Sales", grossSales,
            "Commission Rate", commissionRate);
}

我知道命令行参数有问题。但我不知道如何解决它。有人可以帮帮我吗？

Answer 1

你的程序正在进入这种情况：

if (args.length != 5)
        System.out.printf("Error");

因此，＆＃34;错误＆＃34>打印在输出中。要使用命令行参数运行程序，请使用：

java SalesRepTest arg0 arg1 arg2 arg3 arg4

其中arg0，...，arg4代表你的论点。

Answer 2

正确的代码是：

public class SalesRep{

private String firstName;
private String lastName;
private String employeeID;
private double grossSales;
private double commissionRate;

public SalesRep(String[] args)
{
    if (args.length != 5)
        System.out.printf("Error");
    else
    {
        firstName = args[0];
        lastName = args[1];
        employeeID = args[2];
        grossSales = Double.parseDouble(args[3]);
        commissionRate = Double.parseDouble(args[4]);
    }
    if (grossSales < 0.0)
        throw new IllegalArgumentException
        ("Gross sale must be greater than or equal 0.0");
    if (commissionRate <= 0.0 || commissionRate >= 1.0)
        throw new IllegalArgumentException
        ("Comission rate must be in between 0.0 and 1.0");
}

public String getFirstName()
{
    return firstName;
}
public String getLastName()
{
    return lastName;
}
public String getEmployeeID()
{
    return employeeID;
}
public void setGrossSales(double grossSales)
{
    if (grossSales < 0.0)
        throw new IllegalArgumentException
        ("Gross sales must be greater than or equal 0.0");
    this.grossSales = grossSales;
}
public double getGrossSales()
{
    return grossSales;
}
public void setCommissionRate(double commissionRate)
{
    if (commissionRate <= 0.0 || commissionRate >= 1.0)
        throw new IllegalArgumentException
        ("Comission rate must be in between 0.0 and 1.0");
    this.commissionRate = commissionRate;
}
public double getCommissionRate()
{
    return commissionRate;
}
public double earnings()
{
    return getCommissionRate() * getGrossSales();
}
@Override
public String toString()
{
    return String.format("%s: %s %s%n%s: %s%n%s: %.2f%n%s: %.2f", 
            "Sale Representatives", firstName, lastName,
            "Employee ID", employeeID,
            "Gross Sales", grossSales,
            "Commission Rate", commissionRate);
}        

public static void main(String [] args){
SalesRep s =  new SalesRep(args);
}

}

然后你需要像

一样编译你的代码

javac SalesRep.java

然后你可以运行并提供这样的命令行参数：

java SalesRep arg1 arg2 arg3 arg4 arg4

好的，这将有效。你不能为构造函数提供命令行参数，它只能用于main方法，但你可以将命令行参数作为参数传递给构造函数。

命令行参数

2 个答案: