web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">
    <filter>
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>
 

struts.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE struts PUBLIC
        "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
        "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>
    <package name="myPackge" namespace="/" extends="struts-default">
        <action name="pluralAction" class="com.Action.pluralAction">
            <result name="success">/index.jsp</result>
        </action>
    </package>
</struts>
 

pluralAction

package com.Action;

import com.opensymphony.xwork2.ActionSupport;

public class pluralAction extends ActionSupport {
   private String first1;
   private String check1;
   private String first2;
   private String check;
   private String second1;
   private String check2;
   private String second2;
   private String res1;
   private String check3;
   private String res2;
   private String info;

   public String getFirst1() {
      return first1;
   }

   public void setFirst1(String first1) {
      this.first1 = first1;
   }

   public String getCheck1() {
      return check1;
   }

   public void setCheck1(String check1) {
      this.check1 = check1;
   }

   public String getFirst2() {
      return first2;
   }

   public void setFirst2(String first2) {
      this.first2 = first2;
   }

   public String getCheck() {
      return check;
   }

   public void setCheck(String check) {
      this.check = check;
   }

   public String getSecond1() {
      return second1;
   }

   public void setSecond1(String second1) {
      this.second1 = second1;
   }

   public String getCheck2() {
      return check2;
   }

   public void setCheck2(String check2) {
      this.check2 = check2;
   }

   public String getSecond2() {
      return second2;
   }

   public void setSecond2(String second2) {
      this.second2 = second2;
   }

   public String getRes1() {
      return res1;
   }

   public void setRes1(String res1) {
      this.res1 = res1;
   }

   public String getCheck3() {
      return check3;
   }

   public void setCheck3(String check3) {
      this.check3 = check3;
   }

   public String getRes2() {
      return res2;
   }

   public void setRes2(String res2) {
      this.res2 = res2;
   }

   public String getInfo() {
      return info;
   }

   public void setInfo(String info) {
      this.info = info;
   }

   @Override
   public String execute() throws Exception {
      //第一個複數
      String first1 = getFirst1();
      String check1 = getCheck1();
      String first2 = getFirst2();
      //運算子
      String check = getCheck();
      //第二個複數
      String second1 = getSecond1();
      String check2 = getCheck2();
      String second2 = getSecond2();

      if (isNumeric(first1) && isNumeric(first2) && isNumeric(second1) && isNumeric(second2)) {
         if (check.equalsIgnoreCase("+")) {
            res1 = Integer.parseInt(first1) + Integer.parseInt(second1) + "";
            check3 = "+";
            res2 = Integer.parseInt(first2) + Integer.parseInt(second2) + "";
         } else if (check.equalsIgnoreCase("-")) {
            res1 = Integer.parseInt(first1) - Integer.parseInt(second1) + "";
            check3 = "-";
            res2 = Integer.parseInt(first2) - Integer.parseInt(second2) + "";
         } else if (check.equalsIgnoreCase("*")) {
            res1 = Integer.parseInt(first1) * Integer.parseInt(second1) - Integer.parseInt(second2) * Integer.parseInt(first2) + "";
            check3 = "+";
            res2 = Integer.parseInt(first2) * Integer.parseInt(second1) + Integer.parseInt(second2) * Integer.parseInt(first1) + "";
         } else if (check.equalsIgnoreCase("/")) {
            int x1 = Integer.parseInt(first1) * Integer.parseInt(second1) + Integer.parseInt(second2) * Integer.parseInt(first2);
            int x2 = Integer.parseInt(first2) * Integer.parseInt(second1) - Integer.parseInt(first1) * Integer.parseInt(second2);
            int x3 = Integer.parseInt(second1) * Integer.parseInt(second1) + Integer.parseInt(second2) * Integer.parseInt(second2);
            res1 = x1 / x3 + "";
            check3 = "-";
            res2 = x2 / x3 + "";
         }
         info = "計算結果為:" + res1 + check3 + res2 + "i";
      } else {
         info = "您輸入的格式錯誤";
      }
      return SUCCESS;
   }

   private static boolean isNumeric(String str) {
      for (int i = str.length(); --i >= 0; ) {
         if (!Character.isDigit(str.charAt(i))) {
            return false;
         }
      }
      return true;
   }

   private static String isMore(String test) {
      if (Integer.parseInt(test) < 0) {
         return "-";
      } else {
         return "+";
      }
   }
}
 

index.jsp

<%@ taglib prefix="s" uri="/struts-tags" %>
<%--
  Created by IntelliJ IDEA.
  User: Elijah
  Date: 2018/9/27
  Time: 19:21
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>複數運算</title>
</head>
<body>
<s:form action="pluralAction">
    <s:label value="請輸入第一個複數" theme="simple"/><br/>
    <s:textfield name="first1" theme="simple"/>+<s:textfield name="first2" theme="simple"/>i<br/>
    <br/>
    <s:select list="{'+','-','*','/'}" name="check" label="運算子" theme="simple"/><br/><br/>
    <s:label value="請輸入第二個複數" theme="simple"/><br/>
    <s:textfield name="second1" theme="simple"/>+<s:textfield name="second2" theme="simple"/>i<br/>
    <s:submit value="計算"/>
</s:form>
<br>
<hr width="100%">
<s:property value="info"/>
</body>
</html>