login.jsp<form method="post" action="login">
<input type="submit" value="提交" />
=============================================
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
=============================================
BookDao.javapublic List<TBook> selevtAllBook(){
Connection conn = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
List<TBook> bookList = new ArrayList<TBook>(); conn = this.getConn();
pstmt = conn.prepareStatement("select * from book");
rs = pstmt.executeQuery();
while(rs.next()){
TBook book = new TBook();
book.setBookName(rs.getString("bookName"));
book.setIsbn(rs.getString("isbn"));
book.setAuthor(rs.getString("author"));
book.setPublisher(rs.getString("publisher"));
book.setBookPrice(rs.getFloat("bookPrice"));
book.setDiscount(rs.getDouble("discount"));
book.setBookID(rs.getInt("bookID"));
bookList.add(book);
}
return bookList;
}
=============================================
loginservlet.java
BookDao bookDao = new BookDao();
List<TBook> bookList = bookDao.selevtAllBook();request.setAttribute("id", bookList.get(6));
request.setAttribute("bookList", bookList);
request.getRequestDispatcher("bookList.jsp").forward(request, response);我该如何在bookList.jsp这个页面,或者是在booklistservlet中得到bookList中的那个bookID我在bookListservlet中写request.getParameter("id")怎么不行啊,得到的是null;
<input type="submit" value="提交" />
=============================================
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
=============================================
BookDao.javapublic List<TBook> selevtAllBook(){
Connection conn = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
List<TBook> bookList = new ArrayList<TBook>(); conn = this.getConn();
pstmt = conn.prepareStatement("select * from book");
rs = pstmt.executeQuery();
while(rs.next()){
TBook book = new TBook();
book.setBookName(rs.getString("bookName"));
book.setIsbn(rs.getString("isbn"));
book.setAuthor(rs.getString("author"));
book.setPublisher(rs.getString("publisher"));
book.setBookPrice(rs.getFloat("bookPrice"));
book.setDiscount(rs.getDouble("discount"));
book.setBookID(rs.getInt("bookID"));
bookList.add(book);
}
return bookList;
}
=============================================
loginservlet.java
BookDao bookDao = new BookDao();
List<TBook> bookList = bookDao.selevtAllBook();request.setAttribute("id", bookList.get(6));
request.setAttribute("bookList", bookList);
request.getRequestDispatcher("bookList.jsp").forward(request, response);我该如何在bookList.jsp这个页面,或者是在booklistservlet中得到bookList中的那个bookID我在bookListservlet中写request.getParameter("id")怎么不行啊,得到的是null;
或者你页面中增加一个 hidden的元素赋值给它
你都没有把id放在你的提交参数中怎么能接收到呢
你能确定 bookList 里有7条数据么?
引用楼主 ericfung 的回复:
login.jsp<form method="post" action="login">
<input type="submit" value="提交" />
=============================================
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
……
+
2.request.setAttribute()用request.getParameter()取不出来如果在页面取可以使用el表达式
${id}取值,在servlet中用request.getAttribute(id)取值;
只是把bookList集合中的第7个对象放到request中
request.setAttribute("id", bookList.get(6).getBookID());
才是把bookList集合中的第7个对象的BookId放到request中至于在servlet中接受页面中传递来的id用request.getParameter("id");
另外就是这个list的size 事多少,你打印一下看看
引用楼主 ericfung 的回复:
login.jsp<form method="post" action="login">
<input type="submit" value="提交" />
=============================================
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
request.getParameter不管get还是post都能获取到好吧,request.getAttribute获取的是对象。
lz用form表单post方式提交可以用request.getParameter("id")得到!!