如何用Java编程实现复数类（ComplexNumber），并完成加法、减法、乘法和除法的运算方法？

在Java中，你可以创建一个名为`ComplexNumber`的类来表示复数，它包含两个成员变量分别代表实部（realPart）和虚部（imaginaryPart）。以下是一个基础的实现：

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

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

    // 获取和设置方法
    public double getRealPart() { return realPart; }
    public void setRealPart(double real) { this.realPart = real; }
    public double getImaginaryPart() { return imaginaryPart; }
    public void setImaginaryPart(double imag) { this.imaginaryPart = imag; }

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

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

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

    // 除法（假设除数非零）
    public ComplexNumber divide(ComplexNumber divisor) {
        double denominator = divisor.getRealPart() * divisor.getRealPart() + divisor.getImaginaryPart() * divisor.getImaginaryPart();
        double realQuotient = (this.realPart * divisor.getRealPart() + this.imaginaryPart * divisor.getImaginaryPart()) / denominator;
        double imagQuotient = (this.imaginaryPart * divisor.getRealPart() - this.realPart * divisor.getImaginaryPart()) / denominator;
        return new ComplexNumber(realQuotient, imagQuotient);
    }
}

现在你可以在其他类中实例化`ComplexNumber`对象，并使用这些方法来进行复数运算。例如：

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

    ComplexNumber sum = c1.add(c2); // 输出结果是 (4, 6)
    System.out.println("Sum: " + sum.getRealPart() + ", " + sum.getImaginaryPart());

    // ... 省略其他运算方法的示例
}