The tag library \u5fdbested?is included in Struts 1.1. In this tutorial we are going to explain what are the features of nested tag library and how you can use it. We can manage nested beans easily with the help of struts nested tag library. <\/FONT><\/P> Nested tags are used in the nested context. The Nested tags and its supporting classes extends the base struts tags and making them possible to relate to each other in the nested fashion. In case of Nested tags the original logic of the tags does not change and all the references to beans and bean properties is managed in the nested context. <\/FONT><\/P> As far as bean is concerned, one is associated with another internally and access to all the beans are through the current one. The beans that refers to another is the parent and the second related to the first one is its child. Here both ‘parent’ and ‘child’ denotes a hierarchical structure of beans. Herbert Schildt Object Class Books \tprivate int id; \t\/\/constructors \tpublic Books(int id, String name){ Object Class Authors<\/B> Action form class AuthorsBooksForm Action class AuthorsBooksAction<\/B> <\/PRE> The JSP file<\/FONT><\/B><\/P> Create a new JSP file authorsbooks.jsp<\/B>. authorsbooks.jsp<\/B><\/FONT><\/P> Configure the struts-config.xml<\/FONT><\/B> <\/P> Open the struts-config.xml and add the form bean and action mapping.<\/FONT> <\/P> struts-config.xml<\/B>
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For example, Take an object which represents a Author. Each author related to many book .If this case was translated to bean objects,
the author object would have a reference to the book objects he wrote, and each bunch object would hold a reference to
the chapters in the books.
The author object is the parent to the books object, and the books object is a child of the author object. The books object
is parent to its child chapters objects, and the child chapters objects children of the books object. The author is higher in
the hierarchy than the books, and the chapters lower in the hierarchy to the books.
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<\/B> Teach Yourself C++
Java: The Complete Reference, J2SE
Struts: the complete reference
O’Reilly
<\/B>.NET & XML
ADO.NET in a Nutshell
ADO: ActiveX Data Objects
Create a new struts 1.1 project to to understand nested tags.<\/FONT> <\/P>
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<\/B>Create a class Books<\/B> with properties id<\/B> and name<\/B> in the package roseindia.web.common<\/B>.
Add a getter and setter method for each property.
Also add a constructor that initialize the properties.
Books.java<\/B><\/FONT><\/P>
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\npackage roseindia.web.common;<\/PRE>
public class Books {<\/p>\n
\n\tprivate String name;<\/p>\n
\n\tpublic Books(){}<\/p>\n
\n\t\tthis.id = id;
\n\t\tthis.name = name;
\n\t}
\n\tpublic int getId() {
\n\t\treturn id;
\n\t}
\n\tpublic void setId(int id) {
\n\t\tthis.id = id;
\n\t}
\n\tpublic String getName() {
\n\t\treturn name;
\n\t}
\n\tpublic void setName(String name) {
\n\t\tthis.name = name;
\n\t}
\n}<\/PRE><\/TD><\/TR><\/TBODY><\/TABLE><\/P>
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Create a second java class Authors <\/B>in the same package roseindia.web.common<\/B>.
Add two properties, id<\/B> of type int and name<\/B> of type String and one property books <\/B>of type Collection, which holds a list of books<\/B>.
Add a getter and setter method for each property.
Also add a constructor that initialize the properties.
Authors.java<\/B><\/FONT><\/P>
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\npackage roseindia.web.common;<\/PRE>
import java.util.*;<\/PRE>
public class Authors {
\n\t<\/PRE>\tprivate int id;
\n\tprivate String name;
\n\t<\/PRE>\t\/\/books collection
\n\tprivate Collection books;
\n\t<\/PRE>\t\/\/constructors
\n\tpublic Authors() {}
\n\tpublic Authors(int id, String name, Collection books){
\n\t\tthis.id = id;
\n\t\tthis.name = name;
\n\t\tthis.books = books;
\n\t}<\/PRE>\tpublic Collection getBooks() {
\n\t\treturn books;
\n\t}
\n\tpublic void setBooks(Collection books) {
\n\t\tthis.books = books;
\n\t}
\n\tpublic int getId() {
\n\t\treturn id;
\n\t}
\n\tpublic void setId(int id) {
\n\t\tthis.id = id;
\n\t}
\n\tpublic String getName() {
\n\t\treturn name;
\n\t}
\n\tpublic void setName(String name) {
\n\t\tthis.name = name;
\n\t}
\n}<\/PRE><\/TD><\/TR><\/TBODY><\/TABLE><\/P>
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<\/B>Create a java class AuthorsBooksForm <\/B>in the package roseindia.web.struts.form<\/B>, which extends the class ActionForm of struts.
Add a property authors<\/B> of type Authors<\/B> .
Add a getter and setter method for the property authors<\/B> .
Implement the reset() method of the ActionForm class.
AuthorsBooksForm.java<\/FONT><\/P>
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\npackage roseindia.web.struts.form;<\/PRE>
import java.util.*;<\/PRE>
import org.apache.struts.action.ActionForm;
\nimport org.apache.struts.action.ActionMapping;
\nimport javax.servlet.http.HttpServletRequest;
\nimport javax.servlet.http.HttpServletResponse;
\nimport roseindia.web.common.Authors;
\nimport roseindia.web.common.Books;<\/PRE>public class AuthorsBooksForm extends ActionForm {<\/PRE>\tAuthors authors;<\/PRE>
\n\tpublic void setAuthors(Authors authors) {
\n\t\tthis.authors = authors;
\n\t}<\/PRE>\tpublic Authors getAuthors() {
\n\t\treturn authors;
\n\t}
\n\t<\/PRE>\tpublic void reset(ActionMapping mapping,HttpServletRequest request) {
\n\t\t<\/PRE>\t\t\/\/initial a dummy collection of books
\n\t\tCollection books = new ArrayList();
\n\t\t<\/PRE>\t\tbooks.add(new Books(1, “Teach Yourself C++”));
\n\t\tbooks.add(new Books(2, “Java: The Complete Reference, J2SE”));
\n\t\tbooks.add(new Books(3, “Struts: The Complete Reference”));<\/PRE>
\n\t\t\/\/initial a dummy authors
\n\t\tauthors = new Authors(1, “Herbert Schildt”, books);
\n\t\t<\/PRE>
\n\t}
\n}<\/PRE><\/TD><\/TR><\/TBODY><\/TABLE><\/P>
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Create a java class AuthorsBooksAction<\/B> in the package roseindia.web.struts.action<\/B>, which extends the class Action of struts.
Return the forward example<\/B>.
AuthorsBooksAction.java<\/B><\/FONT><\/P>
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\npackage roseindia.web.struts.action;<\/PRE>
import roseindia.web.struts.form.AuthorsBooksForm;<\/PRE>
import javax.servlet.http.HttpServletRequest;
\nimport javax.servlet.http.HttpServletResponse;
\nimport java.util.*;
\nimport org.apache.struts.action.Action;
\nimport org.apache.struts.action.ActionForm;
\nimport org.apache.struts.action.ActionForward;
\nimport org.apache.struts.action.ActionMapping;<\/p>\npublic class AuthorsBooksAction extends Action {
\n\t<\/PRE>
\n\tpublic ActionForward execute(
\n\t\tActionMapping mapping,
\n\t\tActionForm form,
\n\t\tHttpServletRequest request,
\n\t\tHttpServletResponse response) {
\n\t\tAuthorsBooksForm booksForm = (AuthorsBooksForm) form;
\n\t\t<\/PRE>\t\treturn mapping.findForward(“books”);
\n\t}<\/PRE>}<\/PRE><\/TD><\/TR><\/TBODY><\/TABLE><\/P>
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Add the reference to the tag library nested at the top of the file.<\/FONT><\/P>
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\n<%@ page language=”java”%>
\n<%@ taglib uri=”\/tags\/struts-bean” prefix=”bean” %>
\n<%@ taglib uri=”\/tags\/struts-html” prefix=”html” %>
\n<%@ taglib uri=”\/tags\/struts-logic” prefix=”logic” %>
\n<%@ taglib uri=”\/tags\/struts-nested” prefix=”nested”%>
\n <\/PRE><html>
\n\t<head>
\n\t\t<title>Struts nested tag Example<\/title>
\n\t<\/head>
\n\t<body>
\n\t <h1>Struts nested tag Example<\/h1><\/PRE>\t <b>Author and his books:<\/b>
\n\t\t<html:form action=”\/example” method=”post”> <\/PRE>\t\t\t<nested:nest property=”authors”>
\n\t\t\t\t<\/B><\/FONT><\/PRE>\t\t\t\t<b><nested:write property=”name”\/> <\/b>
\n\t\t\t\t<nested:iterate property=”books”>
\n\t\t\t\t\t\t<\/B><\/FONT><\/PRE>\t\t\t\t\t<ul><li><nested:write property=”name”\/><\/li><\/ul>
\n\t\t\t\t<\/nested:iterate>
\n\t\t\t<\/nested:nest><\/B><\/FONT>
\n\t\t\t<\/PRE>\t\t<\/html:form>
\n\t<\/body>
\n<\/html><\/PRE><\/TD><\/TR><\/TBODY><\/TABLE><\/P>
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