记一次Maven项目改造成SpringBoot项目的过程实践

<properties>
    <spring-boot.version>2.3.0.RELEASE</spring-boot.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>
    <!-- 此处省略其他的依赖 -->
</dependencies>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-dependencies</artifactId>
            <version>${spring-boot.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <version>2.3.12.RELEASE</version>
            <configuration>
                <mainClass>com.xxx.pulsar.PulsarMain</mainClass>
            </configuration>
            <executions>
                <execution>
                    <id>repackage</id>
                    <goals>
                        <goal>repackage</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.8.0</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>

<!-- mybatis-plus -->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.1</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.13</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.27</version>
    <exclusions>
        <exclusion>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
        </exclusion>
        <exclusion>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-api</artifactId>
        </exclusion>
    </exclusions>
</dependency>

@MapperScan("com.xxx.pulsar.mapper")

# 端口
server:
  port: 8001

mybatis:
  # mapper映射文件
  mapper-locations: classpath:mapper/*.xml

spring:
  application:
    # 应用名称
    name: pulsar_demo
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    druid:
      driverClassName: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://localhost:3306/db_test?useUnicode=true&characterEncoding=UTF8&zeroDateTimeBehavior=CONVERT_TO_NULL&useSSL=false&allowPublicKeyRetrieval=true
      username: root
      password: 123456
      initial-size: 10
      max-active: 100
      min-idle: 10
      max-wait: 60000
      pool-prepared-statements: true
      max-pool-prepared-statement-per-connection-size: 20
      time-between-eviction-runs-millis: 60000
      min-evictable-idle-time-millis: 60000
      max-evictable-idle-time-millis: 300000
      validation-query: SELECT 1 FROM DUAL
      # validation-query-timeout: 5000
      test-on-borrow: false
      test-on-return: false
      test-while-idle: true
      connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
      #filters: #配置多个英文逗号分隔(统计，sql注入，log4j过滤)
      filters: stat,wall
      stat-view-servlet:
        enabled: true
        url-pattern: /druid/*

public class MybatisSessionFactory {

    private volatile static SqlSessionFactory sqlSessionFactory;

    private MybatisSessionFactory() {}

    public static void init(String configStr, Properties prop) {
        if (sqlSessionFactory == null) {
            synchronized (MybatisSessionFactory.class) {
                if (sqlSessionFactory == null) {
                    InputStream is = new ByteArrayInputStream(configStr.getBytes());
                    sqlSessionFactory = new SqlSessionFactoryBuilder().build(is, prop);
                }
            }
        }
    }

    public interface Action<RESULT, MAPPER> {
        RESULT action(MAPPER mapper);
    }

    public static <MAPPER, RESULT> RESULT query(Class<MAPPER> mapperClass, Action<RESULT, MAPPER> action) {
        if (sqlSessionFactory == null) {
            throw new NullPointerException("Mybatis未初始化");
        }
        try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
            MAPPER mapper = sqlSession.getMapper(mapperClass);
            return action.action(mapper);
        }
    }

}

private volatile static SqlSessionFactory sqlSessionFactory;

@Autowired
private SqlSessionFactory sqlSessionFactory1;

@PostConstruct
public void update(){
    sqlSessionFactory = sqlSessionFactory1;
}