Put the source code first: dream blog

Project Structure Analysis

If you are already familiar with the SSM development process, you can simplify the creation of SpringBoot project artifacts and directly add the name you want. It is best to be the same as here. src/java is a third-level directory. Don’t complicate this directory.

I skip some annotations by default @Autowired and @Mapper @Repository etc.

I don’t know what AOP is doing, it seems to be a log event anyway, I can’t understand it
config is the background login class intercepted by the interceptor.
The controller is the control layer to realize the interaction between the back-end data and the front-end page
interceptor is a special class for interceptor settings corresponding to intercepting login
mapper database operation management
The pojo (or entity) entity class and its attributes correspond to the database table name and column name
The service service layer is just to perform database operations (mapper)
The utils toolkit generally involves algorithm encryption or plug-ins, etc. I don't quite understand it.
The resources resource package static static resource SpringBoot has defaulted to static/this path refers to the direct/package name. The templates package is a web page, which needs to be configured by mvc.
Generally, the applicaiton.yml configuration file is used

The database datasource does not explain that thymeleaf is the key for the controller to jump to the corresponding webpage. Mybatis locks the location of mapper.xml. This project has no mapper-locaitons configuration because the interface and xml file are put together.

···xml

server:
  port: 8080

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
    type: com.alibaba.druid.pool.DruidDataSource
    url: jdbc:mysql://localhost:3306/myblog


  thymeleaf:
    cache: false
    mode: HTML
    prefix: classpath:/templates/
    suffix: .html

mybatis:
  type-aliases-package: com.dreamchaser.pojo
  configuration:
    log-impl: org.apache.ibatis.logging.slf4j.Slf4jImpl
    log-prefix: mapper.

```

Regarding the pom.xml dependency, I am too lazy to upload, because the source code is already very detailed

Personally recommended development ideas:

Database --> entity class --> dao layer --> service layer --> controller layer --> other support: tools or interception

If you do not use automatic data table generation, you need to create a database and import data first.

Backend src/java:

Entity class

The attribute name is the same as the column name of the data table, so I can understand it by looking at the code.

dao class

The interface of the database operation method, what functions need to be written, and what functions are commonly added, deleted, modified and checked. Pay attention to the use of annotation @mapper statement

or @Repository implements an injectable bean

service class

Contains service interface and service implementation class. The service interface is consistent with the dao interface. The implementation class annotations @Service and @Autowired inject the required dao class to implement the database method you want to operate. Brainless alt+insert.....

The front end uses the thymeleaf template:

Note the use of <html xmlns:th="//www.thymeleaf.org"> to introduce support

extra theme

Here comes the point, using mybatis-generator or Spring data jpa to automatically generate code in two cases

mybatis-generator generates code:

Oral basic configuration:

pom.xml requires mysql mybatis generator-core generator-maven-plugin
maven remember to add

```xml

<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<configuration>
<verbose>true</verbose>
<overwrite>true</overwrite>
</configuration>
</plugin>

```

```yml

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
    type: com.alibaba.druid.pool.DruidDataSource
    url: jdbc:mysql://localhost:3306/myblog
  


  thymeleaf:
    cache: false
    mode: HTML
    prefix: classpath:/templates/
    suffix: .html

#Use mybatis-plus to pay attention to the path similar to the following

mybatis: 
  type-aliases-package: com.dreamchaser.pojo 
  mapper-locations: your path

```

Next, generatorConfig.xml puts down the resources root directory

Change jar package
jdbc connection information
Generate entity class address
Generate map.xml file storage address
Generate interface
table table name
If you want to generate files corresponding to multiple tables, just add table tags
Add maven command line mybatis-generator:generate -e Execute

```xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

<generatorConfiguration>

<classPathEntry location="D:\mysql-connector-java-8.0.28.jar"/>

<context id="MysqlTables" targetRuntime="MyBatis3Simple" defaultModelType="flat">

< property name="autoDelimitKeywords" value="true"/>

<property name="javaFileEncoding" value="utf-8"/>

<
property name="beginningDelimiter" value="`"/>
<property name="endingDelimiter" value="`"/>

<property name="javaFormatter" value="org.mybatis.generator.api.dom.DefaultJavaFormatter"/>

<property name="xmlFormatter" value="org.mybatis.generator.api.dom.DefaultXmlFormatter"/>
<plugin type="org.mybatis.generator.plugins.SerializablePlugin"/>
<plugin type="org.mybatis.generator.plugins.ToStringPlugin"/>

<commentGenerator>
<property name="suppressAllComments" value="true"/>
<property name="suppressDate" value="false"/> < !-- Whether to generate a comment generation timestamp -->
</commentGenerator>

<jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/ssmtest?serverTimezone=UTC" userId="root"
password="123456"/>

<javaTypeResolver>

<property name="forceBigDecimals" value="false "/>
</javaTypeResolver>

<javaModelGenerator targetPackage="com.my.entity" targetProject="src/main/java">

<property name= "enableSubPackages" value="false"/>

<property name="trimStrings" value="true"/>
</javaModelGenerator>

<sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources">
<property name="enableSubPackages" value="false"/>
</sqlMapGenerator>

<javaClientGenerator targetPackage="com.my.dao" targetProject="src/main/java" type="XMLMAPPER">
<property name="enableSubPackages" value="false"/>
</javaClientGenerator>

<!-- There can be multiple tables, each table in the database can write a table, tableName indicates the database table to be matched, or you can use % wildcards in the tableName attribute to match all database tables, only matching tables Only will it automatically generate the file EnableSelectByprimarykey corresponding configuration to indicate whether the corresponding interface is generated->
<table tablename = "user_info" enableCountbyexample = "False"
EnableupDatexample = "Falsee "
Enabledeletebyexample =" False
"EnableSelectByexample =" False "
SelectByexampleQueryid =" False ""
enableSelectByPrimaryKey="true"
enableUpdateByPrimaryKey="true"
enableDeleteByPrimaryKey="true">

</table>

</context>
</generatorConfiguration>

```

After successful operation, the xml file of entity class dao interface class and mapper can be generated

Spring Data Jpa automatically generates data tables

Create a springboot project and add jpa. I won’t say much about other mysql drivers.

```yml

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
    type: com.alibaba.druid.pool.DruidDataSource
    url: jdbc:mysql://localhost:3306/myblog
  


  thymeleaf:
    cache: false
    mode: HTML
    prefix: classpath:/templates/
    suffix: .html
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true

#Use mybatis-plus to pay attention to the path similar to the following

mybatis: 
  type-aliases-package: com.dreamchaser.pojo 
  mapper-locations: your path

```

The way the entity class is written is very important:

@Entity //Tell jpa that this is an entity class and a data table mapping class
@Table(name = "tbl_user") //Specify which data table corresponds to If the table name is omitted, the class name is lowercase
@Id //This is a primary key
@GeneratedValue(strategy = GenerationType.IDENTITY) //Auto-increment primary key
@Column(name="last_name",length = 50) //The column corresponding to the data table
@Column //Omitting the default column name is the attribute name

handwriting an example

```java

@Entity

//Table(name="myname") default table name test

public class Test(){

@Id

@GeneratedValue(strategy=GenerationType.IDENTITY)

private long id;

@Column

private String TestName;

}

```

Just start the SpringBoot project

The resource is introduced, and the server cannot bear the traffic

Build SpringBoot personal blog analysis (project from Code Cloud Chasing Dreams)