【Java Web】设计网页计算一元二次方程的解

水深无声 2022-12-23 06:14 196阅读 0赞

# 通过JSP求解一元二次方程的解 #

### 文章目录 ###

*  通过JSP求解一元二次方程的解
 *  一、问题描述
 *  二、具体实现
 *   *  1.代码
     *  2.程序结构图

--------------------

# 一、问题描述 #

通过创建JSP表单和服务器来接收和计算传入值，计算得出一元二次方程的解。

# 二、具体实现 #

## 1.代码 ##

input.jsp

<%@ page contentType="text/html; charset=gb2312"%>
    <html>
    <body><font size=2>
    <form action="handleData" method="post">
    <br>输入一元二次方程的系数：
    <br>二次项系数a:<input type=text name="a" size=4>
                  一次项系数b:<input type=text name="b" size=4>
                  常数项系数c:<input type=text name="c" size=4>
        <input type=submit value="提交">
        </form>
        </font>
    </body>
    </html>

show.jsp

<%@ page contentType="text/html; charset=gb2312"%>
    <jsp:useBean id="equation" type="mybean.data.Equation" scope="request"/>
    <html>
    <body><font size=2>
                       一元二次方程的系数是：
            <br>二次项系数：<jsp:getProperty name="equation" property="a"/>
                                               一次项系数：<jsp:getProperty name="equation" property="b"/>
                                               常数项：<jsp:getProperty name="equation" property="c"/>
             <br>是一元二次方程吗？<jsp:getProperty name="equation" property="isSquareEquation"/>
             <br>方程的两个根: <jsp:getProperty name="equation" property="rootOne"/>
                           <jsp:getProperty name="equation" property="rootTwo"/>
                           </font>
    </body>
    </html>

circle\_bean.java

package mybean.data;
    
    public class circle_bean {
        
    	double radius;
    	double area;
    	public void setRadius(double a) {
        
    		radius=a;
    	}
    	public double getRadius() {
        
    		return radius;
    	}
    	public void setArea(double b) {
        
    		area=b;
    	}
    	public double getArea() {
        
    		return area;
    	}
    
    }

Equation.java

package mybean.data;
    
    public class Equation {
        
    	double a,b,c;
    	String rootOne,rootTwo;
    	boolean squareEquation;
    	public void setA(double a) {
        
    		this.a=a;
    	}
    	public double getA() {
        
    		return a;
    	}
    	public void setB(double b) {
        
    		this.b=b;
    	}
    	public double getB() {
        
    		return b;
    	}	
    	public void setC(double c) {
        
    		this.c=c;
    	}
    	public double getC() {
        
    		return c;
    	}
    	public void setRootOne(String root) {
        
    		rootOne=root;
    	}
    	public String getRootOne() {
        
    		return rootOne;
    	}
    	public void setRootTwo(String root) {
        
    		rootTwo=root;
    	}
    	public String getRootTwo() {
        
    		return rootTwo;
    	}
    	public void setIsSquareEquation(boolean b) {
        
    		squareEquation=b;
    	}
    	public boolean getIsSquareEquation() {
        
    		return squareEquation;
    	}
    }

Servlet\_control.java

package myservlet.control;
    
    import java.io.*;
    import javax.servlet.*;
    import javax.servlet.http.*;
    import mybean.data.circle_bean;
    
    public class circle_Servlet extends HttpServlet{
        
    	   public void init(ServletConfig config) throws ServletException{
        
    		      super.init(config);
    		   }
    	   public void doPost(HttpServletRequest request,HttpServletResponse response)
                   throws IOException, ServletException{
        
    		   circle_bean circle_bean=new circle_bean();
                request.setAttribute("circle_bean", circle_bean);
                double radius=Double.parseDouble(request.getParameter("radius"));
                
                circle_bean.setRadius(radius);
                double area=0;
                area=3.14*radius*radius;
                circle_bean.setArea(area);
                RequestDispatcher dispatcher=request.getRequestDispatcher("show_area.jsp");
                dispatcher.forward(request, response);
                }
    
    
    }

HandleData.java

package myservlet.control;
    
    import mybean.data.*;
    import java.io.*;
    import javax.servlet.*;
    import javax.servlet.http.*;
    
    public class HandleData  extends HttpServlet{
        
    	   public void init(ServletConfig config) throws ServletException{
        
    		      super.init(config);
    		   }
    	   public void doPost(HttpServletRequest request,HttpServletResponse response)
                throws IOException, ServletException{
        
    		   Equation equ=new Equation();
    		   request.setAttribute("equation", equ);
    		   double a= Double.parseDouble(request.getParameter("a"));
    		   double b= Double.parseDouble(request.getParameter("b"));
    		   double c= Double.parseDouble(request.getParameter("c"));
    		   equ.setA(a);
    		   equ.setB(b);
    		   equ.setC(c);
    		   if(a!=0)
    			   equ.setIsSquareEquation(true);
    		   else
    			   equ.setIsSquareEquation(true);
    		   double disk=b*b-4*a*c;
    		   if(disk<0) {
        
    			   equ.setRootOne("无实根");
    			   equ.setRootTwo("无实根");
    		   }
    		   else {
        
    			   double root1=(-b+Math.sqrt(disk))/(2*a),
    			          root2=(-b-Math.sqrt(disk))/(2*a);
    			   equ.setRootOne(""+root1);
    			   equ.setRootTwo(""+root2);
    		   }
    		   RequestDispatcher dispatcher=request.getRequestDispatcher("show.jsp");
    		   dispatcher.forward(request, response);
    	   }
    	   public void doGet(HttpServletRequest request,HttpServletResponse response)
    	            throws IOException, ServletException{
        
    		   doPost(request,response);
    	   }
    
    }

## 2.程序结构图 ##

程序结构  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80ODcwMTUyMQ_size_16_color_FFFFFF_t_70_pic_center]

实现效果  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80ODcwMTUyMQ_size_16_color_FFFFFF_t_70_pic_center 1]  
![在这里插入图片描述][20201122201112656.png_pic_center]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80ODcwMTUyMQ_size_16_color_FFFFFF_t_70_pic_center]: /images/20221120/9193c2fadf39495d8bcb69a9b613914e.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80ODcwMTUyMQ_size_16_color_FFFFFF_t_70_pic_center 1]: /images/20221120/9a38349975d04a34aa88fbd1f1143b10.png
[20201122201112656.png_pic_center]: https://img-blog.csdnimg.cn/20201122201112656.png#pic_center