SpringBoot基础教程(二)

实现步骤如下。

1.创建一个SpringBoot模块。

File->New->Module->SpringBoot Initializr,如下图：

==注意：如果https://start.spring.io 无法访问造成项目无法创建，可以改用阿里云创建。只需将URL地址改为：https://start.aliyun.com==

2.设置模块的包名和artifactId以及打包方式等等，如下图所示：

3.添加基础依赖如下图所示：

4.编辑pom.xml文档,改写为如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.oracle</groupId>
    <artifactId>springbootparent</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springbootparent</name>
    <description>Demo project for Spring Boot</description>
    <packaging>pom</packaging>

    <properties>
        <java.version>1.8</java.version>
        <junit.version>4.12</junit.version>
        <druid.version>1.1.10</druid.version>
        <lombok.version>1.18.8</lombok.version>
    </properties>

   <dependencies>
        <!--springboot jpa依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <!--springboot的 web依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--支持热部署的依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <!--springboot的测试依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!--mysql驱动依赖-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!--lombok依赖-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
            <version>${lombok.version}</version>
        </dependency>
        <!--alibaba数据连接池中间-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>${druid.version}</version>
        </dependency>
        <!--junit依赖-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

5.配置application.properties

#关于项目的任何配置文档，强烈建议大家粘贴拷贝，千万不要自己去敲。
#上下文配置
server.port=8080
server.servlet.context-path=/springbootparent

#数据源配置
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver

#配置jpa
#帮我们自动生成表结构
spring.jpa.properties.hibernate.hbm2ddl.auto=update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.enable_lazy_load_no_trans=true

#本地MySQL
spring.datasource.url=jdbc:mysql://localhost:3306/springboot?useSSL=false&useUnicode=true&characterEncoding=utf-8&autoReconnect=true&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.initialSize=20
spring.datasource.minIdle=50
spring.datasource.maxActive=500

6.配置application.yml

更推荐使用yml格式配置文档。

#yml格式配置文档范例
server:
  #端口配置
  port: 8080
  #上下文
  servlet:
    context-path: /springbootparent
#数据源配置
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/springboot?useSSL=false&useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true
    username: root
    password: root
    # 使用druid数据源
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver

  jpa:
    show-sql: true
    properties:
      hibernate:
        dialect: org.hibernate.dialect.MySQL5InnoDBDialect
        format_sql: true
        enable_lazy_load_no_trans: true
        hbm2ddl:
          auto: update

7.启动项目

运行ApringbootparentApplication的main方法。控制台出现以下提示信息，说明项目启动成功。

2020-10-18 13:42:21.814  INFO 25468 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  :Tomcat started on port(s): 8080 (http) with context path '/springbootparent'
2020-10-18 13:42:21.816  INFO 25468 --- [  restartedMain] DeferredRepositoryInitializationListener : Triggering deferred initialization of Spring Data repositories…
2020-10-18 13:42:21.816  INFO 25468 --- [  restartedMain] DeferredRepositoryInitializationListener : Spring Data repositories initialized!
2020-10-18 13:42:21.823  INFO 25468 --- [         task-1] com.alibaba.druid.pool.DruidDataSource   : {dataSource-1} inited
2020-10-18 13:42:21.826  INFO 25468 --- [  restartedMain] c.oracle.firstdemo.FirstdemoApplication  : Started ApringbootparentApplicationin 2.97 seconds (JVM running for 7.58)