[JAVA] [For internal use] For those assigned to the Spring Boot project (under construction)

This agenda is used to explain to employees who have been assigned to Spring Boot for the first time.

Prerequisite knowledge

• Java 8 basic syntax
• HTML5, CSS3, JavaScript(ES5)
• Servlet3.1
• HTTP GET, POST

Development environment

• Eclipse Pleiades 4.7
• Java8
• Spring Boot 1.5.10
• PostgreSQL 9.6
• superagent.js

Target

Aim to be able to:

• Add screen
• Addition of client-server processing (addition of Restful API)
• Access DB (MyBatis)
• Understanding each file
• Understanding Controller, Service, etc. corresponding to MVC
• Create and deploy jar with Maven
• Add library from Maven
• Addition of access authority processing (Spring Security)
• Understanding the idea of convention over configuration

Library description

Spring Boot

• A collection of many Spring-related libraries
• Hello World can be displayed with the minimum configuration --Necessary settings such as log settings have been made in advance.
• Is it becoming popular?

MyBatis

• Upgraded version of O / R Mapper. IBatis
• SQL can be written not only in XML but also in annotations

Thmeleaf

• Template engine. Something like JSP.
• While JSP specifies a tag dedicated to JSP, Thymeleaf specifies it with an attribute dedicated to Thmeleaf. --Since the browser just ignores the unrecognized attributes, does the layout break? --Division of labor between designers and programmers
• Spring Boot recommends Thymeleaf instead of JSP

What is Maven

[For super beginners] Maven super introduction

• Build management tool
• Set to pom.xml
• External libraries can be used with <dependency>.

Specific explanation

1. Explanation of folder structure

Spring and MVC

• Controller
• Service
• Model
• View

1. Add screen

procedure

1. Place the HTML in the src / main / static / template folder
2. Create a method in Controller class that returns the created HTML

SampleController.java

public ModelAndView index(ModelAndView mav) {
    mav.setViewName("sample");
    return mav;
}

point

• The VIEW name passed to setViewName does not require an extension (it does not matter if it has an extension). It seems to be able to use both JSP and Thymeleaf.

2. Add Restful API

POST API

• superagent uses post, send methods

POST API (file upload)

• superagent uses post, field, ... methods

Restful API https://qiita.com/TakahiRoyte/items/949f4e88caecb02119aa

• API naming convention
• Use GET and POST properly

3. Access DB with MyBatis

MyBatis Official Website

XML

• mybatis-config.xml
• src/main/resources/mybatis/mapper/*.xml
• Tags can be used to dynamically generate SQL --<if>, <foreach>, <where>, etc.
• You probably don't need the parameterType attribute as it guesses the information MyBatis will receive.

DAO class

• Add @Component
• Call methods such as selectOne and selectList of sqlSession

4. Spring Security Spring Security Reference Thymeleaf + Spring Security integration basics

SecurityConfig.java

Set the following items, etc.

• URLs that can be accessed without logging in
• URLs that cannot be accessed without the role

Thymeleaf

• You can write something like sec: authorize =" hasRole ('ROLE_USER') "

5. How to use Maven

Settings on existing system

• pom.xml (spring-boot-starter-parent) for Spring Boot is specified by<parent> --The version of the external library to be used is also defined. --If you want to specify the version, specify it with <properties>.
• Use of own library
• JavaDoc generation

Maven update in eclipse

After modifying pom.xml, update it with" Right-click project> Maven> Update project ".

Generate jar file (for deployment)

• When you execute the mvn install command, a jar file will be created in the project / target folder.
• If you want to skip the execution of the test code, run mvn install -Dmaven.test.skip = true.

6. Spring Boot related

application.properties https://docs.spring.io/spring-boot/docs/current/reference/html/common-application-properties.html

• File that defines external settings for Spring Boot
• If you open it in Eclipse's "Spring Property Editor", you can complete the input for the key.
• Can also be specified as an argument of the java command. java -jar sample.jar --server.port = 8081 https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-external-config.html https://docs.spring.io/spring-boot/docs/current/reference/html/howto-properties-and-configuration.html

Profile https://area-b.com/blog/2015/01/30/2316/ http://endok.hatenablog.com/entry/2016/06/12/181900 https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-profiles.html

• A mechanism to switch the setting values for each execution environment.
• You can switch to Java class with @Profile ("test ") etc.
• Thymeleaf uses @environment to switch https://blog.tagbangers.co.jp/ja/2015/01/18/thymeleaf-environment-properties

Settings on existing system

• Define 3 types of profiles in the existing system --local: Start in local environment --test: Start on the server of the development environment --release: Start on production server

• Specify a profile like --spring.profiles.active = local in the argument of java command

• ʻApplication.properties is prepared for each profile. --ʻApplication.properties: Default setting value. --ʻApplication-test.properties: Settings for the test environment. --ʻApplication-release.properties: Settings for production environment. Disable tools such as Swagger, enable cache --ʻApplication-local.properties`: Personal settings. Assuming not committing.

Deployment method

1. Run mvn install -Dmaven.test.skip = true with the command to generate the jar file

• Generated in the project / target folder

2. Start the server with the java command

• There is a batch file for starting (start.bat)

Log settings for existing projects

• Adopted a combination of SLF4J (interface) and Logback (implementation) --On older systems, there are many combinations of commons-logging (interface) and log4j (implementation).
• src/main/resources/logbakc.xml --Add individual settings to the log format prepared from the beginning
• Generate field log with @ Slf4j of Lombok
• Log4jdbc was adopted to output the executed SQL (prepared value is also output) to the log.
  • https://qiita.com/YAKINIKU/items/5141c7205f3c67691c92
• Output log before and after Cntroller (AOP)

JUnit

Spring @autowired

Exercise

Prerequisites

• Development environment is in place
• Add functionality to existing projects using Spring Boot
• Ajax communication uses superaget.js

Database

create_table.sql

CREATE table user (
  SERIAL user_id NOT NULL,
  TEXT user_name NOT NULL,
  TEXT section NOT NULL,
  PRIMARY KEY (user_id)
);

Add Controller class

• Check Request / Response in the browser development tool

Creating an HTML file

Create sample.html and display the contents of sample.html with URL /sample.html

• Refer to the value in the message file (message.properties)

Create GET API (1 parameter)

• Receive one number from the client with @RequestParam.
• On the server side, calculate the square of the received number and return it to the client

Create GET API (pass one piece of information)

• Receive one number from the client with @RequestParam.
• On the server side, calculate the square of the received number and return it to the client

Create GET API (pass multiple information)

• Create a bean class and receive multiple pieces of information in that class.
• On the server side, perform some processing on the received information and return it to the client

Create POST API

• Create a POST API. --Receive multiple information --Perform some processing on the received information and return it to the client
• Call API created in JavaScript --Display the contents of the response on the screen

Create POST API (file upload)

• Create a POST API --Receives one file and one string --Save the received file
• Call API created in JavaScript

Access to database

• Add method to DAO class
• Call a method of DAO class from a method in Controller class

SELECT with ʻuser_id`

• Create a method in DAO class --Method to get the result narrowed down by ʻuser_id`

SELECT by user name or department

• Write a WHERE clause using <if>, <where>
• If the information passed to SQL is null, do not narrow down

ʻUser` INSERT into table

• Write a WHERE clause using <if>, <where>
• If the information passed to SQL is null, do not narrow down

Store information in a hierarchical class with a single SELECT statement

• Write SQL statements using <collection>

Maven

Modify pom.xml to use external library

• Check Maven local repository
• Check in Eclipse project properties

Generate a jar file and start the server with the java command

• Generate jar file with mvn command without using Eclipse
• Specify the port number in the argument of the java command
• Change the profile and check that the setting values etc. are switched

Check the log

• Change the log level in logback.xml and check if the log is output / not output

Sentence problem

HTTP

• Explain the difference between HTTP GET and POST. -Request / response header and body

Database

• Explain the features of O / R Mapper based on the advantages and disadvantages.
• You can use # or $ to receive information from Java. Explain the difference.

HelloWorld

Addition of Restful API

@RequestBody, @RequestParam, etc.

file upload

Introduction of MyBatis

Spring Boot Thorough Introduction Chapter 14 Sample Web System

Servlet issues

[Supplement] Comparison with Terasoluna