5

抱歉，我是 Java 新手，我的代码有问题。我已经通读了这些线程，并看到了许多有关此特定错误的示例(java.lang.NoSuchMethodError: main Exception in thread "main")。我似乎无法将我的头脑围绕在我将 ( static void main(String[] args)) 添加到代码中的位置上。如果你们能指出我正确的方向，我将不胜感激。

这是我所拥有的：

public class Employee {


String name;
String department;

double hourlyRate;

Employee(String name, String department, double hourlyRate) {
    this.name = name;
    this.department = department;
    this.hourlyRate = hourlyRate;
}

public void setDepartment(String department) {
    this.department = department;
}

public void setHourlyRate(double hourlyRate) {
    this.hourlyRate = hourlyRate;
}

public String getNameAndDepartment() {
    return name + " " + department;
}

double weeklyPay(int numOfHourWorked) {
    if (numOfHourWorked < 40) {
        return (numOfHourWorked * hourlyRate);
    } else
        return (40 * hourlyRate);

}
}

class UnionEmployee extends Employee {

double dues;

UnionEmployee(String name, String department, double hourlyRate, double dues) {
    super(name, department, hourlyRate);
    this.dues = dues;
}

public void setDues(double dues) {
    this.dues = dues;
}

double weeklyPay(int numOfHourWorked) {
    if (numOfHourWorked <= 40) {
        return (super.weeklyPay(numOfHourWorked));
    } else
return ((super.weeklyPay(40) + ((numOfHourWorked - 40) * hourlyRate * 1.5)) - dues);
}
}

class CommissionEmployee extends Employee {

double commisionRate;
double salesAmount;

CommissionEmployee(String name, String department, double hourlyRate) {
    super(name, department, hourlyRate);
}

public void setCommisionRate(double commisionRate) {
    this.commisionRate = commisionRate;
}

public void setSalesAmount(double salesAmount) {
    this.salesAmount = salesAmount;
}

double weeklyPay(int numOfHourWorked) {
    return (super.weeklyPay(numOfHourWorked) + (commisionRate * salesAmount));
}

}

class TestEmployee {
UnionEmployee uEmp = new UnionEmployee(null, null, 0, 0);
CommissionEmployee cEmp = new CommissionEmployee(null, null, 0);
Employee emp = new Employee(null, null, 0);

void display(Employee emp, int numOfHourWorked) {
    System.out.println("Name and department :" + emp.getNameAndDepartment    ());
    System.out.println("Weekly pay of employee :"
            + emp.weeklyPay(numOfHourWorked));
}

void display(UnionEmployee uEmp, CommissionEmployee cEmp,
        int numOfHourWorked) {
    System.out.println("Weekly Pay for UnionEmployee"
            + uEmp.weeklyPay(numOfHourWorked));
    System.out.println("Weekly Pay for UnionEmployee"
            + cEmp.weeklyPay(numOfHourWorked));
}

}

好的，所以我首先将每个类分成不同的文件。在查看 Java 教程时，它说添加 static void main(String[] args) 教程设置它的方式是这样的：

public class Misc {
static void main(String[] args) {

//body
   }
}

所以我这样做了：

class TestEmployee {

static void main(String[] args) {

UnionEmployee uEmp = new UnionEmployee(null, null, 0, 0);
CommissionEmployee cEmp = new CommissionEmployee(null, null, 0);
Employee emp = new Employee(null, null, 0);

void display(Employee emp, int numOfHourWorked) {
    System.out.println("Name and department :" + emp.getNameAndDepartment    ());
    System.out.println("Weekly pay of employee :"
            + emp.weeklyPay(numOfHourWorked));
}

void display(UnionEmployee uEmp, CommissionEmployee cEmp,
        int numOfHourWorked) {
    System.out.println("Weekly Pay for UnionEmployee"
            + uEmp.weeklyPay(numOfHourWorked));
    System.out.println("Weekly Pay for UnionEmployee"
            + cEmp.weeklyPay(numOfHourWorked));
}

}

}

仍然得到相同的错误：（java.lang.NoSuchMethodError：线程“main”中的主要异常）。

好的，我添加了 public，但现在我得到了这个：

线程“main”java.lang.Error 中的异常：未解决的编译问题：

void is an invalid type for the variable display
Syntax error on token "(", ; expected
Duplicate local variable emp
Syntax error on token ",", ; expected
Syntax error on token ")", ; expected
void is an invalid type for the variable display
Syntax error on token "(", ; expected
Duplicate local variable uEmp
Syntax error on token ",", ; expected
Duplicate local variable cEmp
Syntax error on token ",", ; expected
Duplicate local variable numOfHourWorked
Syntax error on token ")", ; expected

at TestEmployee.main(TestEmployee.java:9)
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1 回答 1

5

您对 main 的问题是它不存在，您需要在程序中添加一个才能运行。将它放在主类中，无论是哪个，但是虽然它需要在类中，在定义类的花括号中，但您还必须确保不要将它放在另一个方法中。

上面，我把它放在 TestEmployee 中。

我还要注意确保上面的每个类都被声明为 public 并且在它自己的文件中。所以上面包含 4 个类的代码应该由 4 个文件组成。

编辑
另外，请务必将您的主要方法声明为公共方法，如以下评论中所述的@Aniket。

编辑 2

  • 您仍然没有将 main 声明为公共方法。
  • 您在 main 方法中嵌入了方法。请记住，在 Java 中您不能这样做，因为所有方法都需要是类级别的。让他们脱离主要方法。
  • 您的代码缩进至少可以说是可怕的，这将使您或我们很难看到您的编码问题。您将需要投入时间和精力来正确缩进代码。如果你这样做了，你会立即看到方法内部有方法。
于 2013-11-10T04:20:52.817 回答