javaBean+jsp实现复数的4则运算

首先，需要定义一个JavaBean类来表示复数，如下所示：

public class Complex {
    private double real; // 实部
    private double imag; // 虚部

    public Complex(double real, double imag) {
        this.real = real;
        this.imag = imag;
    }

    public double getReal() {
        return real;
    }

    public void setReal(double real) {
        this.real = real;
    }

    public double getImag() {
        return imag;
    }

    public void setImag(double imag) {
        this.imag = imag;
    }

    // 定义复数的加法
    public Complex add(Complex c) {
        return new Complex(this.real + c.real, this.imag + c.imag);
    }

    // 定义复数的减法
    public Complex sub(Complex c) {
        return new Complex(this.real - c.real, this.imag - c.imag);
    }

    // 定义复数的乘法
    public Complex mul(Complex c) {
        return new Complex(this.real * c.real - this.imag * c.imag,
                this.real * c.imag + this.imag * c.real);
    }

    // 定义复数的除法
    public Complex div(Complex c) {
        double d = c.real * c.real + c.imag * c.imag;
        return new Complex((this.real * c.real + this.imag * c.imag) / d,
                (this.imag * c.real - this.real * c.imag) / d);
    }
}

然后，在JSP页面中，需要使用JavaBean来进行复数的四则运算。具体实现可以按照以下步骤进行：

1. 在JSP页面中，使用`<jsp:useBean>`指令创建JavaBean对象。

<jsp:useBean id="complex1" class="Complex" scope="page">
    <jsp:setProperty name="complex1" property="real" value="1" />
    <jsp:setProperty name="complex1" property="imag" value="2" />
</jsp:useBean>

<jsp:useBean id="complex2" class="Complex" scope="page">
    <jsp:setProperty name="complex2" property="real" value="3" />
    <jsp:setProperty name="complex2" property="imag" value="4" />
</jsp:useBean>

2. 在JSP页面中，使用脚本let标签来进行复数的四则运算，并将结果保存在JavaBean中。

<%
    Complex result = complex1.add(complex2);
    complex1.setReal(5);
    complex1.setImag(6);
    complex2.setReal(7);
    complex2.setImag(8);
    result = complex1.sub(complex2);
    complex1.setReal(9);
    complex1.setImag(10);
    complex2.setReal(11);
    complex2.setImag(12);
    result = complex1.mul(complex2);
    complex1.setReal(13);
    complex1.setImag(14);
    complex2.setReal(15);
    complex2.setImag(16);
    result = complex1.div(complex2);
%>

3. 在JSP页面中，使用EL表达式来获取JavaBean中保存的结果。

<p>复数1：${complex1.real}+${complex1.imag}i</p>
<p>复数2：${complex2.real}+${complex2.imag}i</p>
<p>复数1+复数2：${complex1.add(complex2).real}+${complex1.add(complex2).imag}i</p>
<p>复数1-复数2：${complex1.sub(complex2).real}+${complex1.sub(complex2).imag}i</p>
<p>复数1*复数2：${complex1.mul(complex2).real}+${complex1.mul(complex2).imag}i</p>
<p>复数1/复数2：${complex1.div(complex2).real}+${complex1.div(complex2).imag}i</p>

以上就是使用JavaBean和JSP实现复数的四则运算的方法。