basic usage of java Spring Framework

Keywords

• Object Dependencies
• Dependency Injection
• Spring Containers

Features of Spring

Dependency Injection

• also called Inversion of Control(IoC)
• Dependency Inversion Principle plus Single Responsibility Principles

### Kinds of DI

1. Constructor Injection

   <constructor-arg ref="cat"></constructor-arg>
   

2. Method(Settor) Injection

   <property name="myname" value="poodle"></property>
   

3. Field Injection (Interface)

Advantages of DI

1. Reduced Dependencies
2. More Resuable Code
3. More Testable Code
4. More Readable Code

Bean definition for DI

Spring Container

• manage the bean object

Spring Container Metadata

1. XML
   • bean definition
   • dependency injection
2. Java Annotations
3. Java Code

Spring Container Types

1. BeanFactory
   • The simplest factory, mainly for DI
   • Used when resources are limited
   • org.springframework.beans.factory.BeanFactory
   • ex) XMLBeanFactory
2. ApplicationContext
   • The advanced and more complex factory
   • Features

     1) Enterprise-aware functions 2) Publish application events to listeners 3) Wire and dispose beans on request

   • org.springframework.context.ApplicationConText
   • ex) ClassPathXmlApplicationContext

     ApplicationContext context = new ClassPathXmlApplicationContext("spring.di.beans.bean.xml");
     HelloWorld helloWorld = (HelloWorld) context.getBean("helloWorld");
     

Embeded Redis Server for Spring test

Spring framework web example in Windows 10

1. install java

• java -version

  openjdk version “11.0.7” 2020-04-14

• add JAVA_HOME to system variables in Windows or profile in linux

  2. maven

• download maven : https://maven.apache.org/download.cgi#
• add MAVEN_HOME to system variable
• add %MAVEN_HOME%\bin on the PATH
• mvn -version

  Apache Maven 3.6.3

  3. Apache Tomcat

• Download : https://tomcat.apache.org/download-80.cgi
• conf/server.xml

  <!-- default -->
  <Connector port="8080" protocol="HTTP/1.1"
             connectionTimeout="20000"
             redirectPort="8443" />
  
  <!-- add URIEncoding -->
  <Connector port="8080" protocol="HTTP/1.1"
             connectionTimeout="20000"
             redirectPort="8443"
             URIEncoding="UTF-8" />
  

• conf/logging.properties

  <!-- default -->
  java.util.logging.ConsoleHandler.encoding = UTF-8
  
  <!-- change encoding if you need -->
  java.util.logging.ConsoleHandler.encoding = EUC-KR
  

• conf/tomcat-users.xml
  • uncomment and change username and password ```xml <!–

  –>

  ```

• Run : [cmd] - change to tomcat bin dir and execute [startup.bat]
• Test : http://localhost:8080

4. Spring Boot

• Create a Spring Boot Project and download
  • https://start.spring.io/
• “src” and “pom.xml” are required and others can be deleted