Test.java
package package1;
public class Test {
double side1 = -1 , side2 = -1 , side3 = -1 , area = -1;
boolean triangle;
public double getSide1() {
return side1;
}
public void setSide1(double side1) {
this.side1 = side1;
}
public double getSide2() {
return side2;
}
public void setSide2(double side2) {
this.side2 = side2;
}
public double getSide3() {
return side3;
}
public void setSide3(double side3) {
this.side3 = side3;
}
public double getArea() {
double p = (side1 + side2 + side3)/2.0;
if(triangle) area = Math.sqrt( p * (p - side1) * (p - side2) * (p - side3) );
return area;
}
public void setArea(double area) {
this.area = area;
}
public boolean isTriangle() {
if(side1<side2+side3 && side2<side1+side3 && side3<side1+side2)
triangle=true;
else triangle=false;
return triangle;
}
public void setTriangle(boolean triangle) {
this.triangle = triangle;
}
}
triangle.jsp
<%@page contentType="text/html;charset=gb2312" pageEncoding="gb2312" %>
<%@page import="package1.Test" %>
<jsp:useBean id="tri" class="package1.Test" scope="page" />
<html>
<head></head>
<body>
<form action="" method="post">
a:<input type="text" name="side1" value="0" />
b:<input type="text" name="side2" value="0" />
c:<input type="text" name="side3" value="0" />
<input type="submit" value="submit" />
</form>
<jsp:setProperty name="tri" property="*" />
三角形的三边是：
边a ：<jsp:getProperty name="tri" property="side1" />
边b ：<jsp:getProperty name="tri" property="side2" />
边c ：<jsp:getProperty name="tri" property="side3" />
<br />
是否能组成三角形：
<jsp:getProperty name="tri" property="triangle" />
<!-- 如果不先判断是否是triangle的话，servlet类中获得面积时的triangle判断恒为假，area输出结果值始终为-1 -->
面积是:
<jsp:getProperty name="tri" property="area" />
</body>
</html>
运行结果：
a: b: c:
三角形的三边是： 边a ：2.0 边b ：4.0 边c ：5.0
是否能组成三角形： true 面积是: 3.799671038392666
时间： 2024-08-15 20:06:57