eGovFrame Training Book II

eGovFrame Center

2012

Table of contents

DI(Dependency Injection), IoC(Inversion of Control)

AOP (Aspect Oriented Programming)

MVC (Model, View, Controller) pattern concept

Programming Procedure based on eGovFrame

Common component concept

Page l 2

I

II

III

IV

V

Page l 3

DI(Dependency Injection), IoC(Inversion of Control)

public class MovieLister{

public void list() {

MovieFinder finder = new MovieFinderImpl();

}

}

public class MovieLister{

public void list() {

MovieFinder finder = Assember.getBean("movieFinder");

}

}

Change the flow of control between classes and reducing dependence(Ease

of maintainability)

When change Impl class, need to change Lister as well

Assembler manages dependency

Composition of eGovFrame

Page l 4

AOP (Aspect Oriented Programming)(1/2)

AOP is a programming paradigm which aims to increase

modularity by allowing the separation of cross-cutting concerns.

Separate add-on services (ex: logging, security, exception, etc)

that are repeated in a number of biz logic code in an information

system as Aspect. Make that a separate module and maintain a

program with configuration files.

When changes occur in additional functions(add-ons), simply by

changing Aspect, the change can be reflected to the biz logic code

and the maintenance of the code will be much easier.

Improve readability as removing duplicated code in business logic.

Composition of eGovFrame

Page l 5

AOP (Aspect Oriented Programming)(2/2) Composition of eGovFrame

[ Separating Aspect] [ Weaving]

Aspect: A modularization of a concern that cuts across multiple objects

Join point: A point during the execution of a program, such as the execution of a method or the

handling of an exception

Advice: Action taken by an aspect at a particular join point

Pointcut: A predicate that matches join points. Advice is associated with a pointcut expression and

runs at any join point matched by the pointcut (for example, the execution of a method with a

certain name)

Weaving: Linking aspects with other application types or objects to create an advised object

Credit

Transfer

Deposit

Withdraw

Calculating

interest

Logging

Security

Transaction

Core Concerns

Cross

cutting

Concerns

Core Concerns

Module

Calculating

interest

Deposit

Withdraw

Credit

Transfer

Crosscutting

Concerns Module

Logging

SecurityWeaving

Page l 6

Object Relational Mapping(ORM)

Features General Development ORM based

Apply MappingNeed direct mapping java classes to the table

columns

Developers can be processed directly in terms of object-

oriented

FlexibilityWhen SQL changes, directly modify source code

and deploy

Can be applied only with modifications of the mapping

information

Standard Pattern No patternMapping information, XML, etc can be applied in the form

of template

DB Control Directly control DB In case of Mapping, direct control can be difficult

Technology in use SQL Persistence framework (Hibernate, iBatis)

Composition of eGovFrame

SQL

Java-Mapping

Business LogicBusiness Logic

DB Column –

Java Class

Mapping

JDBC

DataBase

JDBC

DataBaseBusiness Logic

SQL MAP

(Process SQL in

the form of XML)

Full ORM (Hibernate)

Partial ORM (iBatis)

ORM does not use SQL in source code, instead, directly maps java classes to the

columns of the table or runs and handles SQL in the form of XML

Page l 7

SQL Map Implementation Code Example

• Separate SQL from business logic

• Provide simple transaction control (Provide declarative transaction)

• Provide a familiar SQL-based ORM model

Statement st = null;

ResultSet rs = null;

try {

st = con.createStatement();

StringBuffer query = new StringBuffer();

query.append("\n SELECT A.CHKLST_NO, ");

query.append("\n A.EVALFL_CD, ");

query.append("\n FROM PR_EVALIT_MB A ");

query.append("\n WHERE A.CHKLST_NO = '"

+ sChklstNo + "' ");

query.append("\n ORDER BY EVALIT_NO

rs = st.executeQuery(st.toString());

while(rs.next) {

...

}

} finally {

try {rs.close();} catch (Exception e) {}

try {st.close();} catch (Exception e) {}

}

// Component

List result =

ISqlManagement.getList(“sql.id”,”value”)

// SqlMap.xml

<select id=“id” resultclass =“hmap”>

SELECT A.CHKLST_NO, A.EVALFL_CD FROM

PR_EVALIT_MB A WHERE A.CHKLST_NO = #value#

ORDER BY EVALIT_NO

</select>

Separation of

business

logic and S

QL

enhance

productivity,

maintainabilit

y, and

reusability,

Composition of eGovFrame

Page l 8

MVC (Model, View, Controller) pattern concept

MVC is a software architecture, considered an architectural pattern used in software

engineering.

The MVC pattern isolates ‘domain logic’(the application logic for the user - model) from

user interface (input and presentation - view), then the controller handles the input event

from the user interface to process the request through the domain logic.

It permits independent development, testing and maintenance of each.

Especially, Spring MVC provides DispatcherServlet (*FrontController) that is designed

to implement Presentation layer easier in MVC architecture

Composition of eGovFrame

DispatcherServlet Controller

Http Request

Http Response

ModelView

[ Conceptual Sequence of MVC pattern with DispatcherServlet ]

Page l 9

Spring MVC Architecture Composition of eGovFrame

View

(JSP)

Controller

Model(Biz

Logic)

Dispatcher Servlet

(Front Controller)

DB

Model and

View

HandlerMapping

View

Resolver

Request

Response

RequestContoller

Request

View NameView Response

Model and

View

Model and

View

Spring's Web MVC framework is designed around a DispatcherServlet that

dispatches requests to handlers, with configurable handler mappings, view

resolution.

Page l 10

Programming Procedure based on eGovFrame (1/8)

Presentation Layer Business Layer Data Access Layer

View(JSP)

Dispatcher

Servlet

Controller

Service Interface

ServiceImpl

DAO

DataBase

Request

SQL(XML)

Development Configuration

HandlerMapping

ViewResolver

Spring Config(transaction)

Spring Config(datasource)

Spring Config.

(ORM)

Data Value Object Value Object

Programming Procedure

Spring Module

Page l 11

Output Screen

Programming Procedure based on eGovFrame (2/8) Programming Procedure

Page l 12

Controller : Receive a request and call a service(biz logic)

Implement features such as data binding, forms processing, and muti-action, etc

@Controller@SessionAttributes(types=SampleVO.class)public class EgovSampleController {

/** SampleService */@Resource(name = "sampleService")private EgovSampleService sampleService;

/*** Inquire post list. (pageing)* @param searchVO - SampleDefaultVO* @param model* @return "/sample/egovSampleList"* @exception Exception*/

@RequestMapping(value="/sample/egovSampleList.do")public String selectSampleList(@ModelAttribute("searchVO") SampleDefaultVO searchVO,

ModelMap model) throws Exception {

List sampleList = sampleService.selectSampleList(searchVO);model.addAttribute("resultList", sampleList);

return "/sample/egovSampleList";}

}

JSP Controller Service DAO

VO SQL

Programming ProcedureProgramming Procedure based on eGovFrame (3/8)

Page l 13

Service : Interface that declares methods for business functions

public interface EgovSampleService {

/**

* Inquire post list.

* @param searchVO – VO including search information

* @return post list

* @exception Exception

*/

List selectSampleList(SampleDefaultVO searchVO) throws Exception;

}

JSP Controller ServiceImpl DAO

VO SQL

Service

Programming ProcedureProgramming Procedure based on eGovFrame (4/8)

Page l 14

ServiceImpl : Implementation class that implements methods that defined in a

service

@Service("sampleService")

public class EgovSampleServiceImpl extends AbstractServiceImpl implements

EgovSampleService {

/** SampleDAO */

@Resource(name="sampleDAO")

private SampleDAO sampleDAO;

/**

* Inquire post list.

* @param searchVO - VO including search information

* @return post list

* @exception Exception

*/

public List selectSampleList(SampleDefaultVO searchVO) throws Exception {

return sampleDAO.selectSampleList(searchVO);

}

}

※ Tip : In case of a ServiceImpl, AbstractServiceImpl must be extended

JSP Controller ServiceImpl DAO

VO SQL

Service

Programming ProcedureProgramming Procedure based on eGovFrame (5/8)

Page l 15

DAO : Process data transaction (support iBatis connection)

@Repository("sampleDAO")

public class SampleDAO extends EgovAbstractDAO {

/**

* Inquire post list.

* @param searchVO - VO including search information

* @return post list

* @exception Exception

*/

public list<SampleVO> selectSampleList(SampleVO vo) throws Exception {

return list("sampleDAO.selectSampleList_D", vo);

}

Call EgovAbstractDAO’s list method to run iBatis

Query ID

JSP Controller Service DAO

VO SQL

※ Tip : In case of a DAO, EgovAbsractDAO must be extended.

Programming ProcedureProgramming Procedure based on eGovFrame (6/8)

Method Summary

int delete(java.lang.String queryId, java.lang.Object parameterObject) : Execute delete SQL mapping.

java.lang.Object insert(java.lang.String queryId, java.lang.Object parameterObject) : Execute Insert SQL mapping

java.util.List list(java.lang.String queryId, java.lang.Object parameterObject) : Execute list SQL mapping

java.util.ListlistWithPaging(java.lang.String queryId, java.lang.Object parameterObject, int pageIndex, int pageSize) : Execute sub range list SQL mapping

java.lang.Object selectByPk(java.lang.String queryId, java.lang.Object parameterObject) : select one result by PK

voidsetSuperSqlMapClient(com.ibatis.sqlmap.client.SqlMapClient sqlMapClient) Execute configuration as receiving sqlMapClientin the form of Annotation and calling setSqlMapClient method of super(SqlMapClientDaoSupport)

int update(java.lang.String queryId, java.lang.Object parameterObject) : Execute update SQL mapping

Page l 16

iBatis SQL Map : Define SQL execution query

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE sqlMap PUBLIC "-//iBATIS.com//DTD SQL Map 2.0//EN" "http://www.ibatis.com/dtd/sql-map-2.dtd">

<sqlMap namespace="Sample">

<typeAlias alias="egovMap" type="egovframework.rte.psl.dataaccess.util.EgovMap"/><typeAlias alias="searchVO" type="egovframework.rte.sample.service.SampleDefaultVO"/>

<resultMap id="sample" class="egovframework.rte.sample.service.SampleVO"><result property="id" column="id"/><result property="name" column="name"/><result property="description" column="description"/><result property="useYn" column="use_yn"/><result property="regUser" column="reg_user"/></resultMap>

<select id="sampleDAO.selectSampleList_D" parameterClass="searchVO" resultClass="egovMap“>SELECTID, NAME, DESCRIPTION, USE_YN, REG_USERFROM SAMPLEWHERE 1=1<isEqual prepend="AND" property="searchCondition" compareValue="0">ID = #searchKeyword#</isEqual><isEqual prepend="AND" property="searchCondition" compareValue="1">NAME LIKE '%' || #searchKeyword# || '%'</isEqual>ORDER BY ID DESCLIMIT #recordCountPerPage# OFFSET #firstIndex#</select>

</sqlMap>

JSP Controller Service DAO

VO SQL

Programming ProcedureProgramming Procedure based on eGovFrame (7/8)

Page l 17

VO : The object used for the purpose of data transfer between objects

public class SampleVO extends SampleDefaultVO {

private static final long serialVersionUID = 1753729060514530707L;

/** ID */private String id;

/** Name */private String name;

public String getId() {return id;}

public void setId(String id) {this.id = id;}

public String getName() {return name;}

public void setName(String name) {this.name = name;}

}

JSP Controller Service DAO

VO SQL

Programming ProcedureProgramming Procedure based on eGovFrame (8/8)

Page l 18

Common component concept

A collection of reusable common modules in developing

applications for e-Government projects

An software unit that can run itself

Example

- Notice board, log-in, string validation check, etc

Common Components

Page l 19