java 定义和实现复数类，使其完成复数的加减乘除及输出

在Java中定义和实现复数类，通常我们会创建一个名为`ComplexNumber`的类，它包含两个私有成员变量：实部（realPart）和虚部（imaginaryPart）。下面是一个简单的复数类的定义和实现：

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;
    }

    // 复数运算方法：加法、减法、乘法和除法
    public ComplexNumber add(ComplexNumber other) {
        double newReal = this.realPart + other.realPart;
        double newImag = this.imaginaryPart + other.imaginaryPart;
        return new ComplexNumber(newReal, newImag);
    }

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

    public ComplexNumber multiply(ComplexNumber other) {
        double newReal = this.realPart * other.realPart - this.imaginaryPart * other.imaginaryPart;
        double newImag = this.realPart * other.imaginaryPart + this.imaginaryPart * other.realPart;
        return new ComplexNumber(newReal, newImag);
    }

    // Java的复数除法涉及分母的共轭，这里假设除数不为零
    public ComplexNumber divide(ComplexNumber divisor) {
        double denominatorSquare = divisor.realPart * divisor.realPart + divisor.imaginaryPart * divisor.imaginaryPart;
        double newReal = (this.realPart * divisor.realPart + this.imaginaryPart * divisor.imaginaryPart) / denominatorSquare;
        double newImag = (this.imaginaryPart * divisor.realPart - this.realPart * divisor.imaginaryPart) / denominatorSquare;
        return new ComplexNumber(newReal, newImag);
    }

    // 输出复数
    @Override
    public String toString() {
        if (imaginaryPart >= 0) {
            return "(" + realPart + " + " + imaginaryPart + "i)";
        } else {
            return "(" + realPart + " - " + Math.abs(imaginaryPart) + "i)";
        }
    }
}