SSH框架Action向页面传值差异
SSH框架Action向页面传值方式（本次主要介绍传值方式与jsp取值写法的差异）：
方式 一：在Action中声明一个List变量，生成get/set方法，通过自定义的action中的方法往List集合变量中赋值，再在jsp页面通过<s:iterator value="" var="">取值；
方式 二：在Action方法内声明一个List变量，然后通过数据库查询将结果用List集合变量存储，之后通过ServletActionContext.getRequest().setAttribute("list", list);将集合通过request传值到jsp页面，再在jsp页面通过<s:iterator value="" var="">取值；
ServletActionContext.getRequest().setAttribute("list", list)
等同于：HttpServletRequest=ServletActionContext.getRequest()；获取request请求
request.setAttribute("list", list);将list集合放入request请求，"list"表示页面取值的name或Id;list表示当前Action的查询结果集；
方式 一Action中get|set传值：
action：
1 package top.malloc.ssh.action;
2
3 import java.util.List;
4
5 import javax.servlet.http.HttpServletRequest;
6
7 import org.apache.struts2.ServletActionContext;
8
9 import top.malloc.ssh.bean.TbBook;
10 import top.malloc.ssh.service.ITbBookService;
11
12 public class BookAction {
13
14 private ITbBookService bookService;
15
16 private TbBook tbbook;
17 //申明List
18 private List< TbBook> list;
19 //产生get|set
20 public List<TbBook> getList() {
21 return list;
22 }
23
24 public void setList(List<TbBook> list) {
25 this.list = list;
26 }
27
28 public ITbBookService getBookService() {
29 return bookService;
30 }
31
32 public void setBookService(ITbBookService bookService) {
33 this.bookService = bookService;
34 }
35
36 public TbBook getTbbook() {
37 return tbbook;
38 }
39
40 public void setTbbook(TbBook tbbook) {
41 this.tbbook = tbbook;
42 }
43
44 public String addBook(){
45 bookService.save(tbbook);
46 System.out.println("success!");
47 return "success";
48 }
49
50 public String selectById(){
51 bookService.findById(tbbook.getBookid());
52 return "success";
53 }
54 //action自定义方法，查询赋值
55 public String selectAll(){
56 list=bookService.findAll();
57 return "list";
58 }
59
60 public String delBook(){
61 bookService.delete(tbbook);
62 return "success";
63 }
64
65 public String updBook(){
66
67 return "success";
68 }
69
70
71 }
private List< TbBook> list;
public List<TbBook> getList() {
return list;
}
public void setList(List<TbBook> list) {
this.list = list;
}
public String selectAll(){
//数据库查询赋值
list=bookService.findAll();
return "list";
}
jsp取值：
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <%@ taglib prefix="s" uri="/struts-tags"%> 3 4 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 5 <html> 6 <head> 7 <title>list.jsp</title> 8 </head> 9 10 <body> 11 <s:form action="selectAll_book.action" method="post"> 12 <h4 align="center">书籍查询</h4> 13 <table border="3" align="center"> 14 <tr> 15 <td>书名</td> 16 <td>作者</td> 17 <td>ISBN</td> 18 <td>出版社</td> 19 </tr> 20 <s:iterator value="list" var="book"> 21 <tr> 22 <td><s:property value="#book.bookname" /></td> 23 <td><s:property value="#book.author" /></td> 24 <td><s:property value="#book.isbn" /></td> 25 <td><s:property value="#book.publish" /></td> 26 </tr> 27 <br /> 28 </s:iterator> 29 </table> 30 </s:form> 31 </body> 32 </html>
get|set取值写法：<s:iterator value="list" var="book">
方式 二request传值：
1 package top.malloc.ssh.action;
2
3 import java.util.List;
4 import org.apache.struts2.ServletActionContext;
5 import top.malloc.ssh.bean.TbBook;
6 import top.malloc.ssh.service.ITbBookService;
7
8 public class BookAction {
9
10 private ITbBookService bookService;
11
12 private TbBook tbbook;
13
14 public ITbBookService getBookService() {
15 return bookService;
16 }
17
18 public void setBookService(ITbBookService bookService) {
19 this.bookService = bookService;
20 }
21
22 public TbBook getTbbook() {
23 return tbbook;
24 }
25
26 public void setTbbook(TbBook tbbook) {
27 this.tbbook = tbbook;
28 }
29
30 public String addBook(){
31 bookService.save(tbbook);
32 System.out.println("success!");
33 return "success";
34 }
35
36 public String selectById(){
37 bookService.findById(tbbook.getBookid());
38 return "success";
39 }
40
41 public String selectAll(){
42 //申明list集合变量
43 List list=bookService.findAll();
44 //将集合存入request请求
45 ServletActionContext.getRequest().setAttribute("list", list);
46 return "list";
47 }
48
49 public String delBook(){
50 bookService.delete(tbbook);
51 return "success";
52 }
53
54 public String updBook(){
55
56 return "success";
57 }
58
59
60 }
public String selectAll(){
//申明list集合变量
List list=bookService.findAll();
//将集合存入request请求
ServletActionContext.getRequest().setAttribute("list", list);
return "list";
}
jsp取值：
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <%@ taglib prefix="s" uri="/struts-tags"%> 3 4 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 5 <html> 6 <head> 7 <title>list.jsp</title> 8 </head> 9 10 <body> 11 <s:form action="selectAll_book.action" method="post"> 12 <h4 align="center">书籍查询</h4> 13 <table border="3" align="center"> 14 <tr> 15 <td>书名</td> 16 <td>作者</td> 17 <td>ISBN</td> 18 <td>出版社</td> 19 </tr> 20 <s:iterator value="#request.list" var="book"> 21 <tr> 22 <td><s:property value="#book.bookname" /></td> 23 <td><s:property value="#book.author" /></td> 24 <td><s:property value="#book.isbn" /></td> 25 <td><s:property value="#book.publish" /></td> 26 </tr> 27 <br /> 28 </s:iterator> 29 </table> 30 </s:form> 31 </body> 32 </html>
request取值：<s:iterator value="#request.list" var="book">
效果演示：
