EL表达式的具体用法我暂时先不说了
这里就简单说说注意点
package test.com.servlet.jstl;
public class Book {
private String isbn;
private String title;
private Double price;
public Book(String isbn,String title,double price) {
this.isbn = isbn;
this.title = title;
this.price = price;
}
public String getIsbn() {
return isbn;
}
public void setIsbn(String isbn) {
this.isbn = isbn;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public Double getPrice() {
return price;
}
public void setPrice(Double price) {
this.price = price;
}
}
package test.com.servlet.jstl;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet(urlPatterns = {"/books"})
public class BooksServlet extends HttpServlet{
/**
*
*/
private static final long serialVersionUID = -8775932947610791148L;
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
List<Book> books = new ArrayList<Book>();
Book book1 = new Book("978-213213213", "Java 7:A Beginner‘s Tutorial", 45.00);
Book book2 = new Book("978-446767456", "Struts 2 Design and Programming: A Tutorial", 49.95);
Book book3 = new Book("978-545644452", "Dimensional Data Warehousing with MySQL: A Tutorial", 39.95);
books.add(book1);
books.add(book2);
books.add(book3);
request.setAttribute("books", books);
RequestDispatcher rd = request.getRequestDispatcher("/books.jsp");
rd.forward(request, response);
}
}
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!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>Book List</title>
</head>
<body>
Books in Simple Table
<table>
<tr>
<td>ISBN</td>
<td>Title</td>
</tr>
<c:forEach var = "book" items="${books }">
<tr>
<td>${book.isbn }</td>
<td>${book.title }</td>
</tr>
</c:forEach>
</table>
</body>
</html>
访问后页面如下
${book.isbn }这个怎么取值的？
其实是通过Book的getIsbn()
不信咱们把getTitle()方法注释起来再访问下试试
结果就成这样了
javax.el.PropertyNotFoundException: Property ‘title‘ not readable on type test.com.servlet.jstl.Book
at javax.el.BeanELResolver$BeanProperty.read(BeanELResolver.java:357)
at javax.el.BeanELResolver$BeanProperty.access$000(BeanELResolver.java:305)
at javax.el.BeanELResolver.getValue(BeanELResolver.java:97)
......
所以简单理解，他是通过实体属性的get方法获得的
时间： 2024-10-24 11:12:22