Top Banner
Project Refinery, Inc. 1 STRUTS Part of the Jakarta Project Sponsored by the Apache Software Foundation Developed by: Roger W Barnes of Project Refinery, Inc. Introduction to Struts
77

Struts Intro Course(1)

Sep 03, 2014

Download

Technology

wangjiaz

 
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Struts Intro Course(1)

Project Refinery, Inc. 1

STRUTSPart of the Jakarta ProjectSponsored by theApache Software Foundation

Developed by: Roger W Barnes of Project Refinery, Inc.

Introduction to Struts

Page 2: Struts Intro Course(1)

Project Refinery, Inc. 2

STRUTS Objectives

Course OverviewUnit 1 - Model-View-Controller Design

PatternUnit 2 - Model ComponentsUnit 3 - View ComponentsUnit 4 - Controller ComponentsUnit 5 - Tag Libraries

Page 3: Struts Intro Course(1)

Project Refinery, Inc. 3

STRUTS Objectives

Unit 6 - STRUTS Configuration FileUnit 7 - Web Application Descriptor FileUnit 8 - Application Resources FileUnit 9 – Resources

Page 4: Struts Intro Course(1)

Project Refinery, Inc. 4

Model-View-Controller Design Pattern

Unit 1

Page 5: Struts Intro Course(1)

Project Refinery, Inc. 5

STRUTS MVC Design Pattern

Central controller mediates application flow

Controller delegates to appropriate handler

Handlers are tied to model componentsModel encapsulates business logicControl forwarded back through the

Controller to the appropriate View

Page 6: Struts Intro Course(1)

Project Refinery, Inc. 6

STRUTS MVC Design Pattern

Page 7: Struts Intro Course(1)

Project Refinery, Inc. 7

STRUTS MVC Design Pattern

3 Major Components in STRUTS Servlet controller (Controller) Java Server Pages (View) Application Business Logic (Model)

Controller bundles and routes HTTP request to other objects in framework

Controller parses configuration file

Page 8: Struts Intro Course(1)

Project Refinery, Inc. 8

STRUTS MVC Design Pattern

Configuration file contains action mappings (determines navigation)

Controller uses mappings to turn HTTP requests into application actions

Mapping must specify A request path Object type to act upon the request

Page 9: Struts Intro Course(1)

Project Refinery, Inc. 9

Model Components

Unit 2

Page 10: Struts Intro Course(1)

Project Refinery, Inc. 10

STRUTS Model Components

Model divided into concepts Internal state of the system Actions that can change that state

Internal state of system represented by JavaBeans Enterprise JavaBeans

Page 11: Struts Intro Course(1)

Project Refinery, Inc. 11

STRUTS Model Components

JavaBeans and Scope Page – visible within a single JSP page, for the

lifetime of the current request Request – visible within a single JSP page, as well

as to any page or servlet that is included in this page, or forwarded to by this page

Session – visible to all JSP pages and servlets that participate in a particular user session, across one or more requests

Application - visible to all JSP pages and servlets that are part of a web application

Page 12: Struts Intro Course(1)

Project Refinery, Inc. 12

STRUTS Model Components

ActionForm Beans Extends the ActionForm class Create one for each input form in the application If defined in the ActionMapping configuration file,

the Controller Servlet will perform the following: Check session for instance of bean of appropriate class If no session bean exists, one is created automatically For every request parameter whose name corresponds to

the name of a property in the bean, the corresponding setter method will be called

The updated ActionForm bean will be passed to the Action Class perform() method when it is called, making these values immediately available

Page 13: Struts Intro Course(1)

Project Refinery, Inc. 13

STRUTS Model Components

When coding ActionForm beans consider: The ActionForm class itself requires no specific

methods to be implemented. It is used to identify the role these particular beans play in the overall architecture. Typically, an ActionForm bean will have only property getter and property setter methods, with no business logic

The ActionForm object also offers a standard validation mechanism. If you override a "stub" method, and provide error messages in the standard application resource, Struts will automatically validate the input from the form

Page 14: Struts Intro Course(1)

Project Refinery, Inc. 14

STRUTS Model Components

Continued Define a property (with associated getXxx() and

setXxx() methods) for each field that is present in the form. The field name and property name must match according to the usual JavaBeans conventions

Place a bean instance on your form, and use nested property references. For example, you have a "customer" bean on your Action Form, and then refer to the property "customer.name" in your JSP view. This would correspond to the methods customer.getName() and customer.setName(string Name) on your customer bean

Page 15: Struts Intro Course(1)

Project Refinery, Inc. 15

STRUTS Model Components

System State Beans Actual state of a system is normally represented

as a set of one or more JavaBeans classes, whose properties define the current state

A shopping cart system, for example, will include a bean that represents the cart being maintained for each individual shopper, and will (among other things) include the set of items that the shopper has currently selected for purchase

Page 16: Struts Intro Course(1)

Project Refinery, Inc. 16

STRUTS Model Components

Business Logic Beans Should encapsulate the functional logic of your

application as method calls on JavaBeans designed for this purpose

For maximum code re-use, business logic beans should be designed and implemented so that they do not know they are being executed in a web application environment

For small to medium sized applications, business logic beans might be ordinary JavaBeans that interact with system state beans passed as arguments, or ordinary JavaBeans that access a database using JDBC calls

Page 17: Struts Intro Course(1)

Project Refinery, Inc. 17

STRUTS Model Components

Business Logic Beans - Continued For larger applications, these beans will

often be stateful or stateless Enterprise JavaBeans (EJBs)

Page 18: Struts Intro Course(1)

Project Refinery, Inc. 18

STRUTS Model Components

Accessing Relational Databases Struts can define the datasources for an

application from within its standard configuration file

A simple JDBC connection pool is also provided

Page 19: Struts Intro Course(1)

Project Refinery, Inc. 19

View Components

Unit 3

Page 20: Struts Intro Course(1)

Project Refinery, Inc. 20

STRUTS View Components

Internationalized Messages Struts builds upon Java platform to provide assistance for

building internationalized and localized applications Locale - fundamental Java class that supports internationalization ResourceBundle - supports messages in multiple languages PropertyResourceBundle - standard implementation of

ResourceBundle that allows you to define resources using the same "name=value" syntax used to initialize properties files

MessageFormat - allows you to replace portions of a message string with arguments specified at run time

MessageResources - lets you treat a set of resource bundles like a database, and allows you to request a particular message string for a particular Locale

Page 21: Struts Intro Course(1)

Project Refinery, Inc. 21

STRUTS View Components

ApplicationResources.properties Contains the messages in the default

language for your server. If your default language is English, you might have an entry like this: prompt.hello=Hello

ApplicationResources_xx.properties Contains the same messages in the

language whose ISO language code is "xx"

Page 22: Struts Intro Course(1)

Project Refinery, Inc. 22

STRUTS View Components

Forms and FormBean interactions HTML Forms and their limitations Errors not easily handled

Page 23: Struts Intro Course(1)

Project Refinery, Inc. 23

STRUTS View Components

<%@ page language="java" %> <%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %> <%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %><html:html> <head> <title> <bean:message key="logon.title"/> </title> <body bgcolor="white"> <html:errors/> <html:form action=“/logonpath.do"> <table border="0" width="100%"> <tr> <th align="right"> <html:message key="prompt.username"/>

</th> <td align="left"> <html:text property="username" size="16"/>

</td> </tr> <tr> <td align="right"> <html:submit> <bean:message

key="button.submit"/> </html:submit> </td>

Page 24: Struts Intro Course(1)

Project Refinery, Inc. 24

STRUTS View Components

Building Forms with Struts The taglib directive tells the JSP page compiler

where to find the tag library descriptor for the Struts tag library

message tag is used to look up internationalized message strings from a MessageResources object containing all the resources for this application

The errors tag displays any error messages that have been stored by a business logic component, or nothing if no errors have been stored

Page 25: Struts Intro Course(1)

Project Refinery, Inc. 25

STRUTS View Components

Building Forms with Struts – continued The form tag renders an HTML <form> element, based on

the specified attributes The form tag also associates all of the fields within this form

with a request scoped FormBean that is stored under the key FormName

The form bean can also be specified in the Struts configuration file, in which case the Name and Type can be omitted here

The text tag renders an HTML <input> element of type "text“ The submit and reset tags generate the corresponding

buttons at the bottom of the form

Page 26: Struts Intro Course(1)

Project Refinery, Inc. 26

STRUTS View Components

Input field types supported checkboxes hidden fields password input fields radio buttons reset buttons select lists options submit buttons text input fields textareas

Page 27: Struts Intro Course(1)

Project Refinery, Inc. 27

STRUTS View Components

Useful Presentation Tags [logic] iterate repeats its tag body once for each

element of a specified collection (which can be an Enumeration, a Hashtable, a Vector, or an array of objects)

[logic] present depending on which attribute is specified, this tag checks the current request, and evaluates the nested body content of this tag only if the specified value is present

[logic] notPresent the companion tag to present, notPresent provides the same functionality when the specified attribute is not present

Page 28: Struts Intro Course(1)

Project Refinery, Inc. 28

STRUTS View Components

Useful Presentation Tags – continued [html] link generates a HTML <a> element as an

anchor definition or a hyperlink to the specified URL, and automatically applies URL encoding to maintain session state in the absence of cookie support

[html] img generates a HTML <img> element with the ability to dynamically modify the URLs specified by the "src" and "lowsrc" attributes in the same manner that <html:link> can

[bean] parameter retrieves the value of the specified request parameter, and defines the result as a page scope attribute of type String or String

Page 29: Struts Intro Course(1)

Project Refinery, Inc. 29

STRUTS View Components

Automatic Form Validation Struts offers an additional facility to validate the

input fields it has received To utilize this feature, override the validate()

method in your ActionForm class The validate() method is called by the controller

servlet after the bean properties have been populated, but before the corresponding action class's perform() method is invoked

Page 30: Struts Intro Course(1)

Project Refinery, Inc. 30

STRUTS View Components

Page Composition with Includes The development of the various segments

of a site is easier if you can divide up the work, and assign different developers to the different segments

Use the include capability of JavaServer Pages technology to combine the results into a single result page, or use the include tag provided with Struts

Page 31: Struts Intro Course(1)

Project Refinery, Inc. 31

STRUTS View Components

Page Composition with Includes – continued There are three types of include available,

depending on when you want the combination of output to occur:

An <%@ include file="xxxxx" %> directive can include a file that contains java code or jsp tags

The include action (<jsp:include page="xxxxx" flush="true" />) is processed at request time, and is handled transparently by the server

The bean:include tag takes either a an argument "forward" representing a logical name mapped to the jsp to include, or the "id" argument, which represents a page context String variable to print out to the jsp page

Page 32: Struts Intro Course(1)

Project Refinery, Inc. 32

Controller Components

Unit 4

Page 33: Struts Intro Course(1)

Project Refinery, Inc. 33

STRUTS Controller Components

Struts includes a Servlet that implements the primary function of mapping a request URI to an Action class (ActionServlet)

Page 34: Struts Intro Course(1)

Project Refinery, Inc. 34

STRUTS Controller Components

Your primary responsibilities are: Write an Action class (that is, an extension of the

Action class) for each logical request that may be received

Write the action mapping configuration file (in XML) that is used to configure the controller servlet (struts-config.xml)

Update the web application deployment descriptor file (in XML) for your application to include the necessary Struts components

Add the appropriate Struts components to your application

Page 35: Struts Intro Course(1)

Project Refinery, Inc. 35

STRUTS Controller Components

Action Classes: The Action class defines a perform

method that you override public ActionForward

perform(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException;

Page 36: Struts Intro Course(1)

Project Refinery, Inc. 36

STRUTS Controller Components

The goal of an Action class is to process this request, and then to return an ActionForward object that identifies the JSP page (if any) to which control should be forwarded to generate the corresponding response

Page 37: Struts Intro Course(1)

Project Refinery, Inc. 37

STRUTS Controller Components

A typical Action class will implement the following logic in its perform() method Validate the current state of the user's session If validation has not yet occurred, validate the form bean

properties as necessary Perform the processing required to deal with this request Update the server-side objects that will be used to create

the next page of the user interface Return an appropriate ActionForward object that

identifies the JSP page to be used to generate this response, based on the newly updated beans

Page 38: Struts Intro Course(1)

Project Refinery, Inc. 38

STRUTS Controller Components

Design issues to remember when coding Action classes include the following The controller Servlet creates only one instance of

your Action class, and uses it for all requests. Thus, you need to code your Action class so that it operates correctly in a multi-threaded environment, just as you must code a Servlet's service() method safely

The most important principle that aids in thread-safe coding is to use only local variables, not instance variables, in your Action class

Page 39: Struts Intro Course(1)

Project Refinery, Inc. 39

STRUTS Controller Components

Design issues to remember when coding Action classes include the following – continued The beans that represent the Model of your system

may throw exceptions due to problems accessing databases or other resources. You should trap all such exceptions in the logic of your perform() method, and log them to the application logfile

As a general rule, allocating scarce resources and keeping them across requests from the same user (in the user's session) can cause scalability problems

Page 40: Struts Intro Course(1)

Project Refinery, Inc. 40

STRUTS Controller Components

The ActionMapping Implementation type - Fully qualified Java class name of the Action

implementation class used by this mapping. name - The name of the form bean defined in the config

file that this action will use path - The request URI path that is matched to select this

mapping. See below for examples of how matching works. unknown - Set to true if this action should be configured

as the default for this application, to handle all requests not handled by another action. Only one action can be defined as a default within a single application.

validate - Set to true if the validate() method of the action associated with this mapping should be called.

Page 41: Struts Intro Course(1)

Project Refinery, Inc. 41

STRUTS Controller Components

The Actions Mapping Configuration File The developer's responsibility is to create an XML

file named struts-config.xml, and place it in the WEB-INF directory of your application

The outermost XML element must be <struts-config>

Inside of the <struts-config> element, there two important elements that you use to describe your actions:

Page 42: Struts Intro Course(1)

Project Refinery, Inc. 42

STRUTS Controller Components

<form-beans>This section contains your form bean definitions. You use a <form-bean> element for each form bean, which has the following important attributes:

name: The name of the request or session level attribute that this form bean will be stored as

type: The fully-qualified Java classname of your form bean

Page 43: Struts Intro Course(1)

Project Refinery, Inc. 43

STRUTS Controller Components

<action-mappings>This section contains your action definitions. You use an <action> element for each of your actions you would like to define. Each action element has requires the following attributes to be defined:

path: The application context-relative path to the action type: The fully qualified java classname of your Action

class name: The name of your <form-bean> element to use

with this action

Page 44: Struts Intro Course(1)

Project Refinery, Inc. 44

STRUTS Controller Components

One more section of good use is the <data-sources> section, which specifies data sources that your application can use.This is how you would specify a basic data source for your application inside of struts-config.xml:

<struts-config> <data-sources> <data-source autoCommit="false" description="Example Data Source Description"

driverClass="org.postgresql.Driver" maxCount="4" minCount="2" password="mypassword" url="jdbc:postgresql://localhost/mydatabase" user="myusername"/>

</data-sources> </struts-config>

Page 45: Struts Intro Course(1)

Project Refinery, Inc. 45

STRUTS Controller Components

The Web Application Deployment Descriptor The final step in setting up the application

is to configure the application deployment descriptor (stored in file WEB-INF/web.xml) to include all the Struts components that are required

Page 46: Struts Intro Course(1)

Project Refinery, Inc. 46

Tag Libraries

Unit 5

Page 47: Struts Intro Course(1)

Project Refinery, Inc. 47

STRUTS Tag Libraries

HTML TagsBean TagsLogic TagsTemplate TagsCustom Tags

Page 48: Struts Intro Course(1)

Project Refinery, Inc. 48

HTML Tags The tags in the Struts HTML library form a

bridge between a JSP view and the other components of a Web application. Since a dynamic Web application often depends on gathering data from a user, input forms play an important role in the Struts framework. Consequently, the majority of the HTML tags involve HTML forms. Other important issues addressed by the Struts-HTML tags are messages, error messages, hyperlinking and internationalization.

Page 49: Struts Intro Course(1)

Project Refinery, Inc. 49

HTML Tags HTML "form" tags

button cancel checkboxes file hidden image multibox password input fields radio buttons reset buttons

HTML "form" tags select lists with

embedded option options submit buttons text input fields textareas

Page 50: Struts Intro Course(1)

Project Refinery, Inc. 50

HTML Tags – Typical HTML Form<HTML>

<BODY>

<FORM>

<TABLE WIDTH="100%">

<TR><TD>First Name</TD>

<TD><INPUT TYPE="TEXT" NAME="Name" SIZE="40" MAXLENGTH="40"></TD></TR>

<TR><TD>Street Address</TD>

<TD><INPUT TYPE="TEXT" NAME="Address" SIZE="40" MAXLENGTH="40"></TD></TR>

<TR><TD>City</TD>

<TD><INPUT TYPE="TEXT" NAME="City" SIZE="20" MAXLENGTH="20"></TD></TR>

<TR><TD>State</TD>

<TD><INPUT TYPE="TEXT" NAME="State" SIZE="2" MAXLENGTH="2"></TD></TR>

<TR><TD>Postal Code</TD>

<TD><INPUT TYPE="TEXT" NAME="ZipCode" SIZE="9" MAXLENGTH="9"></TD></TR>

<TR><TD ALIGN=CENTER><INPUT TYPE="SUBMIT" NAME="Submit" VALUE="Save"></TD>

<TD><INPUT TYPE="RESET" NAME="Reset" VALUE="Cancel"></TD></TR>

</TABLE>

</FORM>

</BODY>

</HTML>

Page 51: Struts Intro Course(1)

Project Refinery, Inc. 51

HTML Tags – Typical Struts Form<HTML:HTML>

<BODY>

<HTML:FORM Action="/CustomerForm" focus=“name” >

<TABLE WIDTH="100%">

<TR><TD><bean:message key="customer.name"/></TD>

<TD><HTML:TEXT property="name" size="40" maxlength="40" /></TD></TR>

<TR><TD><bean:message key="customer.address"/></TD>

<TD><HTML:TEXT property="address" size ="40" maxlength ="40" /></TD></TR>

<TR><TD><bean:message key="customer.city"/></TD>

<TD><HTML:TEXT property="city" size ="20" maxlength ="20" /></TD></TR>

<TR><TD><bean:message key="customer.state"/></TD>

<TD><HTML:TEXT property="state" size ="2" maxlength ="2" /></TD></TR>

<TR><TD><bean:message key="customer.zip"/></TD>

<TD><HTML:TEXT property="zip" size ="9" maxlength ="9" /></TD></TR>

<TR><TD ALIGN=CENTER><html:submit property="action" value ="Save"/></TD>

<TD><html:reset property="action" value ="Reset"/></TD></TR>

</TABLE>

</HTML:FORM>

</BODY>

</HTML:HTML>

Page 52: Struts Intro Course(1)

Project Refinery, Inc. 52

Bean Tags The "struts-bean" tag library provides substantial enhancements to

the basic capability provided by <jsp:useBean>, as discussed in the following sections: Bean Properties - Extended syntax to refer to JavaBean properties with

simple names (same as the standard JSP tags <jsp:getProperty> and <jsp:setProperty>), nested names (a property named address.city returns the value retrieved by the Java expression getAddress().getCity()), and indexed names (a property named address[3] retrieves the fourth address from the indexed "address" property of a bean).

Bean Creation - New JSP beans, in any scope, can be created from a variety of objects and APIs associated with the current request, or with the servlet container in which this page is running.

Bean Output - Supports the rendering of textual output from a bean (or bean property), which will be included in the response being created by your JSP page.

Page 53: Struts Intro Course(1)

Project Refinery, Inc. 53

Bean TagsTag Name Description

cookie Define a scripting variable based on the value(s) of the specified request cookie.

define Define a scripting variable based on the value(s) of the specified bean property.

header Define a scripting variable based on the value(s) of the specified request header.

include Load the response from a dynamic application request and make it available as a bean.

message Render an internationalized message string to the response.

page Expose a specified item from the page context as a bean.

parameter Define a scripting variable based on the value(s) of the specified request parameter.

resource Load a web application resource and make it available as a bean.

size Define a bean containing the number of elements in a Collection or Map.

struts Expose a named Struts internal configuration object as a bean.

write Render the value of the specified bean property to the current JspWriter.

Page 54: Struts Intro Course(1)

Project Refinery, Inc. 54

Bean Tag Example<table border="2">

<tr>

<th align="left"><bean:message key=“imagebroker.lob”/></th>

<th align="left"><bean:message key=“imagebroker.unitnbr”/></th>

<th align="left"><bean:message key=“imagebroker.onbase_dns”/></th>

</tr>

<logic:iterate id="image" property="collection"

name="ImageLocationListForm">

<tr>

<td><a href="ImageLocationListForm.do?lob=<bean:write name='image'

property='lob'/>

&unitnbr=<bean:write name='image' property='unitnbr'/>

&onbase_dns=<bean:write name='image' property='onbase_dns'/>" >

<bean:write name="image" property="lob"/></a></td>

<td><bean:write name="image" property="unitnbr"/></td>

<td><bean:write name="image" property="onbase_dns"/></td>

</tr>

</logic:iterate>

</table>

Page 55: Struts Intro Course(1)

Project Refinery, Inc. 55

Logic Tags

The Logic tag library contains tags that are useful in managing conditional generation of output text, looping over object collections for repetitive generation of output text, and application flow management.

Page 56: Struts Intro Course(1)

Project Refinery, Inc. 56

Logic Tags For tags that do value comparisons (equal,

greaterEqual, greaterThan, lessEqual, lessThan, notEqual), the following rules apply: The specified value is examined. If it can be converted

successfully to a double or a long, it is assumed that the ultimate comparison will be numeric (either floating point or integer). Otherwise, a String comparison will be performed.

The variable to be compared to is retrieved, based on the selector attribute(s) (cookie, header, name, parameter, property) present on this tag. It will be converted to the appropriate type for the comparison, as determined above.

A request time exception will be thrown if the specified variable cannot be retrieved, or has a null value.

The specific comparison for this tag will be performed, and the nested body content of this tag will be evaluated if the comparison returns a true result.

Page 57: Struts Intro Course(1)

Project Refinery, Inc. 57

Logic Tags For tags that do substring matching (match,

notMatch), the following rules apply: The specified variable is retrieved, based on the

selector attribute(s) (cookie, header, name, parameter, property) present on this tag. The variable is converted to a String, if necessary.

A request time exception will be thrown if the specified variable cannot be retrieved, or has a null value.

The specified value is checked for existence as a substring of the variable, in the position specified by the location attribute, as follows: at the beginning (if location is set to start), at the end (if location is set to end), or anywhere (if location is not specified).

Page 58: Struts Intro Course(1)

Project Refinery, Inc. 58

Logic TagsTag Name Description

empty Evaluate the nested body content of this tag if the requested variable is either null or an empty string.

equal Evaluate the nested body content of this tag if the requested variable is equal to the specified value.

forward Forward control to the page specified by the specified ActionForward entry.

greaterEqual Evaluate the nested body content of this tag if requested variable is greater than or equal to specified value.

greaterThan Evaluate the nested body content of this tag if the requested variable is greater than the specified value.

iterate Repeat the nested body content of this tag over a specified collection.

lessEqual Evaluate the nested body content of this tag if requested variable is greater than or equal to specified value.

lessThan Evaluate the nested body content of this tag if the requested variable is less than the specified value.

match Evaluate the nested body content of this tag if specified value is an appropriate substring of requested variable.

messagesNotPresent Generate the nested body content of this tag if the specified message is not present in this request.

messagesPresent Generate the nested body content of this tag if the specified message is present in this request.

notEmpty Evaluate the nested body content of this tag if the requested variable is neither null nor an empty string.

notEqual Evaluate the nested body content of this tag if the requested variable is not equal to the specified value.

notMatch Evaluate the nested body content of tag if specified value not an appropriate substring of requested variable.

notPresent Generate the nested body content of this tag if the specified value is not present in this request.

present Generate the nested body content of this tag if the specified value is present in this request.

redirect Render an HTTP Redirect

Page 59: Struts Intro Course(1)

Project Refinery, Inc. 59

Logic Tags - Example<html:html>

<head>

<title><bean:message key="imagebrokerlink.title"/></title>

<META name="GENERATOR" content="IBM WebSphere Studio">

</head>

<body>

<html:form action="/ImageLocationForm" >

<center>

<font size=3>

<br>

<b>

<logic:notEqual property="action" name="ImageLocationForm" value="Insert">

<bean:message key="imagelocationdetail.title"/>

</logic:notEqual>

<logic:equal property="action" name="ImageLocationForm" value="Insert">

<bean:message key="imagelocationinsert.title"/>

</logic:equal>

Page 60: Struts Intro Course(1)

Project Refinery, Inc. 60

Template Tags

The Template tag library contains three tags: put, get, and insert. Put tags put content into request scope, which is retrieved by a get tag in a different JSP page (the template). That template is included with the insert tag.

Page 61: Struts Intro Course(1)

Project Refinery, Inc. 61

Template Tags Insert Inserts (includes, actually) a

template. Templates are JSP pages that include parameterized content. That content comes from put tags that are children of insert tags.

Put Puts content into request scope.Get Gets the content from request scope

that was put there by a put tag.

Page 62: Struts Intro Course(1)

Project Refinery, Inc. 62

Custom Tags <%@ taglib uri="WEB-INF/imagebroker.tld" prefix="broker" %>

<table width=750 cellspacing=0 cellpadding=2 border=2 >

<tr>

<td><broker:form

lob='<%=test.getLob()%>'

unitnbr='<%=test.getUnitnbr()%>'

userid='<%=test.getUserid()%>' >

<broker:doctype value="Invoice"/>

<broker:keyword name="CompanyNbr" value="55555"/>

<broker:keyword name="PONbr" value="M12345"/>

<broker:constraint name="FromDate" value="02/02/2002"/>

<broker:constraint name="ToDate" value="02/28/2002"/>

Image Broker Link Test

</broker:form>

</td>

</tr>

</table>

Page 63: Struts Intro Course(1)

Project Refinery, Inc. 63

Custom Tags – tld File<tag>

<name>doctype</name>

<tagclass>com.pri.brokertag.ImageBrokerDoctype</tagclass>

<attribute>

<name>value</name>

<required>true</required>

<rtexprvalue>true</rtexprvalue>

</attribute>

</tag>

Page 64: Struts Intro Course(1)

Project Refinery, Inc. 64

Custom Tags – Tag Classpublic class ImageBrokerDoctype extends TagSupport {

private String value = null;

public int doStartTag() throws JspException

{

Hashtable ht = null;

String keyword_count = null;

int iCnt = 0;

HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();

ht = (Hashtable) request.getAttribute("keyword_parms");

keyword_count = (String)

request.getAttribute("queryobject_count");

iCnt ++;

ht.put("QueryObject" + iCnt, value);

request.setAttribute("keyword_parms", ht);

request.setAttribute("queryobject_count", new String(new

Integer(iCnt).toString()));

return EVAL_PAGE; }

}

Page 65: Struts Intro Course(1)

Project Refinery, Inc. 65

STRUTS Configuration File

Unit 6

Page 66: Struts Intro Course(1)

Project Refinery, Inc. 66

STRUTS Configuration FileThe developer's responsibility is to

create an XML file named struts-config.xml, and place it in the WEB-INF directory of your application. This format of this document is constrained by it's definition in "struts-config_1_0.dtd". The outermost XML element must be <struts-config>.

Page 67: Struts Intro Course(1)

Project Refinery, Inc. 67

STRUTS Configuration File• Inside of the <struts-config> element, there are two important elements

that are used to describe your actions: <form-beans>This section contains your form bean definitions. You use a <form-bean> element for each form bean, which has the following important attributes:

• name: A unique identifier for this bean, which will be used to reference it in corresponding action mappings. Usually, this is also the name of the request or session attribute under which this form bean will be stored.

• type: The fully-qualified Java classname of your form bean. <action-mappings>This section contains your action definitions. You use an <action> element for each of your actions you would like to define. Each action element requires the following attributes to be defined:

• path: The application context-relative path to the action • type: The fully qualified java classname of your Action class • name: The name of your <form-bean> element to use with this

action

Page 68: Struts Intro Course(1)

Project Refinery, Inc. 68

Struts-config.xml<?xml version="1.0" encoding="ISO-8859-1" ?>

<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.0//EN"

"http://jakarta.apache.org/struts/dtds/struts-config_1_0.dtd">

<struts-config>

<!-- ========== Form Bean Definitions =================================== -->

<form-beans>

<form-bean name="CryptForm" type="com.pri.imagebrokerWeb.CryptForm" />

</form-beans>

<!-- ========== Global Forward Definitions ============================== -->

<global-forwards>

<forward name="start" path="/index.html"/>

</global-forwards>

<!-- ========== Action Mapping Definitions ============================== -->

<action-mappings>

<action path="/CryptForm" type="com.pri.imagebrokerWeb.CryptAction"

name="CryptForm" scope="request" input="/pgCrypt.jsp">

<forward name="encrypt" path="/pgCryptDisplay.jsp"/>

</action>

</action-mappings>

</struts-config>

Page 69: Struts Intro Course(1)

Project Refinery, Inc. 69

Web Application Descriptor File

Unit 7

Page 70: Struts Intro Course(1)

Project Refinery, Inc. 70

Web.xml FileThe final step in setting up the

application is to configure the application deployment descriptor (stored in file WEB-INF/web.xml) to include all the Struts components that are required. Using the deployment descriptor for the example application as a guide, we see that the following entries need to be created or modified.

Page 71: Struts Intro Course(1)

Project Refinery, Inc. 71

Web.xml File<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"

"http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">

<web-app id="WebApp">

<display-name>imagebrokerWeb</display-name>

<!-- Action Servlet Configuration -->

<servlet id="Servlet_1">

<servlet-name>action</servlet-name>

<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>

<init-param>

<param-name>application</param-name><param-value>imagebrokerWeb</param-value>

</init-param>

<init-param>

<param-name>config</param-name><param-value>WEB-INF/struts-config.xml</param-value>

</init-param>

</servlet>

Page 72: Struts Intro Course(1)

Project Refinery, Inc. 72

Web.xml File - continued <!-- Action Servlet Mapping -->

<servlet-mapping>

<servlet-name>action</servlet-name>

<url-pattern>*.do</url-pattern>

</servlet-mapping>

<!-- The Welcome File List -->

<welcome-file-list>

<welcome-file>index.html</welcome-file>

</welcome-file-list>

Page 73: Struts Intro Course(1)

Project Refinery, Inc. 73

Web.xml File - continued <!-- Struts Tag Library Descriptors -->

<taglib>

<taglib-uri>WEB-INF/struts-bean.tld</taglib-uri>

<taglib-location>/WEB-INF/struts-bean.tld</taglib-location>

</taglib>

<taglib>

<taglib-uri>WEB-INF/struts-html.tld</taglib-uri>

<taglib-location>/WEB-INF/struts-html.tld</taglib-location>

</taglib>

<taglib>

<taglib-uri>WEB-INF/struts-logic.tld</taglib-uri>

<taglib-location>/WEB-INF/struts-logic.tld</taglib-location>

</taglib>

</web-app>

Page 74: Struts Intro Course(1)

Project Refinery, Inc. 74

Application Resources File

Unit 8

Page 75: Struts Intro Course(1)

Project Refinery, Inc. 75

Application.properties Fileerror.cryptvalue.required=<li>You must enter some text.</li>

error.lob.required=<li>You must enter the Line of Business.</li>

error.unitnbr.required=<li>You must enter the Unit Number.</li>

error.onbase_dns.required=<li>You must enter the OnBase DNS.</li>

imagebroker.linkname=Project Refinery, Inc.

imagebroker.title=pri Image Broker

imagebrokerlink.title=pri Image Broker Link Test

imagelocationlist.title=Image Location List

imagelocationdetail.title=Image Location Detail

imagelocationinsert.title=Image Location Insert

errors.header=

errors.footer=

Page 76: Struts Intro Course(1)

Project Refinery, Inc. 76

Resources

Unit 9

Page 77: Struts Intro Course(1)

Project Refinery, Inc. 77

Resources

Main Struts Web Site http://jakarta.apache.org/struts/index.html

Struts User Guide http://jakarta.apache.org/struts/userGuide/index.html

Various Struts Resources http://jakarta.apache.org/struts/resources.html

Ted Husted Web Site http://www.husted.com/struts/