我是新来的，这个世界的代码。我试图建立一个简单的Web应用程序，有CoffeeOrder.html代表欢迎页面，CoffeeProcess.jsp处理计算（在这种情况下，我不做任何计算）和CoffeeBean.java类。
这些都是我的代码的附件。
CoffeeBean.java
package coffee.bean;
public class CoffeeBean implements java.io.Serializable
{
private int numSugar;
private double price;
private String typeCoffee;
//default constructor
public CoffeeBean()
{}
//normal constructor
public CoffeeBean(int numSugar, double price, String typeCoffee)
{
this.numSugar = numSugar;
this.price = price;
this.typeCoffee = typeCoffee;
}
//accessor method
public int getSugar()
{ return numSugar; }
public double getPrice()
{ return price; }
public String getType()
{ return typeCoffee; }
//mutator method
public void setSugar(int numSugar)
{ this.numSugar = numSugar; }
public void setPrice(double price)
{ this.price = price; }
public void setCoffee(String typeCoffee)
{ this.typeCoffee = typeCoffee; }
}
CoffeeOrder.html
<!DOCTYPE html>
<html>
<head>
<title>Order</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<h1>Javabeans in JSP</h1><br>
<h1>Coffee Order</h1>
<form action='CoffeeProcess.jsp' method='POST'>
Type of Coffee <input type='text' name='typeCoffee'/><br>
Number of Sugar <input type='text' name='numSugar'/><br>
Price <input type='text' name='price'/><br>
<input type='Submit' value='Submit'/>
</form>
</body>
</html>
咖啡过程.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Javabeans in JSP</title>
</head>
<body>
<h1>Customer Order</h1>
<jsp:useBean id = "coffee" scope="request" class= "coffee.bean.CoffeeBean">
<jsp:setProperty name = "coffee" property = "numSugar" value="1"/>
<jsp:setProperty name = "coffee" property = "price" value="23"/>
<jsp:setProperty name = "coffee" property = "typeCoffee" value="asf"/>
</jsp:useBean>
<p>Type of Coffee:<jsp:getProperty name="coffee" property="typeCoffee"/></p>
<p>Number of Sugar:<jsp:getProperty name="coffee" property="numSugar"/></p>
<p>Price:<jsp:getProperty name="coffee" property="price"/></p>
</body>
</html>
这是我在CoffeeOrder.html中点击提交按钮时得到的错误。
某个人 :c
你已经得到了这个错误，因为jsp是能够找到的。typeCoffee 你给你的方法起的名字是getter setter方法。getType() 和 setType() 同样 numSugar 以及是不匹配的。相反，你的 getter-setter 应该像下面一样。
//getter for numSugar
public int getNumSugar() {
return numSugar;
}
//setter for numSugar
public void setNumSugar(int numSugar) {
this.numSugar = numSugar;
}
//getter for typeCoffee
public String getTypeCoffee() {
return typeCoffee;
}
//setter for typeCoffee
public void setTypeCoffee(String typeCoffee) {
this.typeCoffee = typeCoffee;
}
另外，如果你需要传递来自于 form 对你的 <jsp:setProperty..> 你可以像下面这样做。
<jsp:useBean id = "coffee" scope="request" class= "coffee.bean.CoffeeBean">
<jsp:setProperty name = "coffee" property = "numSugar" value="${param.numSugar}"/>
<jsp:setProperty name = "coffee" property = "price" value="${param.price}"/>
<jsp:setProperty name = "coffee" property = "typeCoffee" value="${param.typeCoffee}"/>
</jsp:useBean>