Java编写一个复数类，具有实部虚部成员变量，可以完成加减 乘除获得实部虚部等操作，并编写一个主类对其进行测试

在Java中，我们可以创建一个名为`ComplexNumber`的类来表示复数，包括实部（realPart）和虚部（imaginaryPart）作为成员变量。这里是一个简单的示例：

public class ComplexNumber {
    private double realPart;
    private double imaginaryPart;

    // 构造函数
    public ComplexNumber(double real, double imaginary) {
        this.realPart = real;
        this.imaginaryPart = imaginary;
    }

    // 获取实部和虚部
    public double getRealPart() {
        return realPart;
    }

    public double getImaginaryPart() {
        return imaginaryPart;
    }

    // 加法运算
    public ComplexNumber add(ComplexNumber other) {
        double newReal = this.realPart + other.getRealPart();
        double newImaginary = this.imaginaryPart + other.getImaginaryPart();
        return new ComplexNumber(newReal, newImaginary);
    }

    // 减法运算
    public ComplexNumber subtract(ComplexNumber other) {
        double newReal = this.realPart - other.getRealPart();
        double newImaginary = this.imaginaryPart - other.getImaginaryPart();
        return new ComplexNumber(newReal, newImaginary);
    }

    // 乘法运算
    public ComplexNumber multiply(ComplexNumber other) {
        double realProduct = this.realPart * other.getRealPart() - this.imaginaryPart * other.getImaginaryPart();
        double imaginaryProduct = this.realPart * other.getImaginaryPart() + this.imaginaryPart * other.getRealPart();
        return new ComplexNumber(realProduct, imaginaryProduct);
    }

    // 除法运算（假设除数不为0）
    public ComplexNumber divide(ComplexNumber divisor) {
        double denominator = divisor.getRealPart() * divisor.getRealPart() + divisor.getImaginaryPart() * divisor.getImaginaryPart();
        double newReal = (this.realPart * divisor.getRealPart() + this.imaginaryPart * divisor.getImaginaryPart()) / denominator;
        double newImaginary = (this.imaginaryPart * divisor.getRealPart() - this.realPart * divisor.getImaginaryPart()) / denominator;
        return new ComplexNumber(newReal, newImaginary);
    }

    // 打印复数
    @Override
    public String toString() {
        return "Complex Number (" + realPart + " + " + imaginaryPart + "i)";
    }
}

接下来，在`Main`类中我们可以对这个复数类进行测试：

public class Main {
    public static void main(String[] args) {
        ComplexNumber c1 = new ComplexNumber(3, 4);
        ComplexNumber c2 = new ComplexNumber(1, 2);

        System.out.println("c1: " + c1);
        System.out.println("c2: " + c2);

        ComplexNumber sum = c1.add(c2);
        System.out.println("Sum: " + sum);

        ComplexNumber difference = c1.subtract(c2);
        System.out.println("Difference: " + difference);

        ComplexNumber product = c1.multiply(c2);
        System.out.println("Product: " + product);

        try {
            ComplexNumber quotient = c1.divide(c2);
            System.out.println("Quotient: " + quotient);
        } catch (ArithmeticException e) {
            System.out.println("Cannot divide by zero");
        }
    }
}

在这个例子中，我们创建了两个复数对象，进行了加、减、乘、除的操作，并打印出结果。