用Java写一个定义一个复数类，完成复数的加法运算，并进行测试。要求：使用重载构造方法和setComplex方法，为变量成员赋值。

好的，以下是一个复数类的代码示例：

public class Complex {
    private double real;
    private double imag;

    // 无参构造方法
    public Complex() {
        this.real = 0.0;
        this.imag = 0.0;
    }

    // 带参构造方法
    public Complex(double real, double imag) {
        this.real = real;
        this.imag = imag;
    }

    // 设置复数的实部和虚部
    public void setComplex(double real, double imag) {
        this.real = real;
        this.imag = imag;
    }

    // 获取复数的实部和虚部
    public double getReal() {
        return this.real;
    }

    public double getImag() {
        return this.imag;
    }

    // 复数加法运算
    public Complex add(Complex other) {
        double real = this.real + other.getReal();
        double imag = this.imag + other.getImag();
        return new Complex(real, imag);
    }

    // 测试代码
    public static void main(String[] args) {
        Complex c1 = new Complex(1.0, 2.0);
        Complex c2 = new Complex(2.0, 3.0);
        Complex c3 = c1.add(c2);
        System.out.printf("(%f+%fi) + (%f+%fi) = %f + %fi", 
                          c1.getReal(), c1.getImag(), 
                          c2.getReal(), c2.getImag(), 
                          c3.getReal(), c3.getImag());
    }
}

输出结果为：`(1.000000+2.000000i) + (2.000000+3.000000i) = 3.000000 + 5.000000i`。