java web--javabean技术

Javabean是Java web程序的重要组件，它是一些封装了数据和操作的功能类，供JSP货Servlet调用，完成数据封装和数据处理等功能。

设计一个标准的javabean通常遵循以下规则：

1.Javabean是一个公共类。

2.Javabean类具有一个公共的无参的构造方法。

3.Javabean所有的属性定义为私有的。

4.在Javabean中，需要每队属性提供两个公共方法（get方法和set方法）。

5.定义Javabean时，通常放在一个命名的包下。

一、基于JSP脚本访问Javabean

package beans;

public class a02a_add {
private double number1;
private double number2;
private double sum;
public a02a_add() {
	super();
	// TODO Auto-generated constructor stub
}
public a02a_add(double number1, double number2) {
	super();
	this.number1 = number1;
	this.number2 = number2;
}
public double getNumber1() {
	return number1;
}
public void setNumber1(double number1) {
	this.number1 = number1;
}
public double getNumber2() {
	return number2;
}
public void setNumber2(double number2) {
	this.number2 = number2;
}
public double getSum() {
	sum=number1+number2;
	return sum;
}
public void setSum(double sum) {
	this.sum = sum;
}
public double Sum()
{
	return number1+number2;
}
}

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<p>按照格式要求，输入两个整数</p>
<hr>
<form action="a02b_yx.jsp" method="post">
加数：&nbsp;<input type="text" name="number1"><br>
<br>被加数：<input type="text" name="number2"><br>
<br>
<input type="submit" value="提交">
&nbsp;&nbsp;
<input type="reset" value="取消">
</form>
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    <%@page import="beans.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
String a=request.getParameter("number1");
String b=request.getParameter("number2");
int aa=Integer.parseInt(a);
int bb=Integer.parseInt(b);
a02a_add ad=new a02a_add(aa,bb);
%>
<%=a %>+<%=b %>=<%=ad.Sum() %>
</body>
</html>

2.基于JSP动作标签访问Javabean

package beans;

public class a02a_add {
private double number1;
private double number2;
private double sum;
public a02a_add() {
	super();
	// TODO Auto-generated constructor stub
}
public a02a_add(double number1, double number2) {
	super();
	this.number1 = number1;
	this.number2 = number2;
}
public double getNumber1() {
	return number1;
}
public void setNumber1(double number1) {
	this.number1 = number1;
}
public double getNumber2() {
	return number2;
}
public void setNumber2(double number2) {
	this.number2 = number2;
}
public double getSum() {
	sum=number1+number2;
	return sum;
}
public void setSum(double sum) {
	this.sum = sum;
}
public double Sum()
{
	return number1+number2;
}
}

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<p>按照格式要求，输入两个整数</p>
<hr>
<form action="a03b_yx.jsp" method="post">
加数：&nbsp;<input type="text" name="number1"><br>
<br>被加数：<input type="text" name="number2"><br>
<br>
<input type="submit" value="提交">
&nbsp;&nbsp;
<input type="reset" value="取消">
</form>
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    <%@page import="beans.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<jsp:useBean id="add" class="beans.a02a_add"></jsp:useBean>
<jsp:setProperty property="*" name="add"></jsp:setProperty>
显示结果：
<jsp:getProperty property="number1" name="add"/>
+
<jsp:getProperty property="number2" name="add"/>
=
<jsp:getProperty property="sum" name="add"/>
</body>
</html>

java web--javabean技术

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