Spring boot 使用笔记

在命令行配置参数

使用jar包启动的时候，参数必须以 -- 开头参数放在结尾，或者使用-D开头，参数放在开始才符合jar参数规范
使用 mvn启动时，参数必须以 -D开头才符合mvn参数规范

java -jar target/demo.jar --spring.profiles.active=dev 
# 或者
java -Dspring.profiles.active=dev -jar target/demo.jar
mvn spring-boot:run -Dspring.profiles.active=dev 

创建一个普通的非执行的jar包(library)

移除pom文件中的spring-boot-maven-plugin

多数据源和Mybatis配置

java例子

@Configuration
// sqlSessionFactoryRef必填，否则使用@Primary注解的SqlSessionFactory
@MapperScan(value = "com.demo.app.mapper",
    sqlSessionFactoryRef = Demo1Config.SQL_SESSION_FACTORY)
@EnableTransactionManagement(proxyTargetClass = true)
public class Demo1Config {
    public static final String SQL_SESSION_FACTORY = "mybatisSqlSessionFactoryApp";
    // ac-adaptor
    @Bean
    @ConfigurationProperties("spring.datasource.demo1")
    public DataSource dataSourceApp() {
        DataSource dataSource = DruidDataSourceBuilder.create().build();
        return dataSource;
    }

    @Bean
    public DataSourceTransactionManager txManagerApp() {
        DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
        dataSourceTransactionManager.setDataSource(dataSourceApp());
        return dataSourceTransactionManager;
    }

    @Bean(name = AcAppAdaptorConfig.SQL_SESSION_FACTORY)
    public SqlSessionFactory mybatisSqlSessionFactoryApp() throws Exception {
        SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSourceApp());
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                                              .getResources(
                                                  "classpath*:config/mapper/com/demo/app/mapper/*.xml"));
        return sessionFactory.getObject();
    }
}

第二个数据源

@Configuration
@MapperScan(value = "com.petkit.ac.adaptor.chain.mapper",
    sqlSessionFactoryRef = AcChainAdaptorConfig.SQL_SESSION_FACTORY)
@EnableTransactionManagement(proxyTargetClass = true)
public class AcChainAdaptorConfig {

    public static final String SQL_SESSION_FACTORY = "mybatisSqlSessionFactoryChain";
    // ac-adaptor

    @Bean(name = AcChainAdaptorConfig.SQL_SESSION_FACTORY)
    public SqlSessionFactory mybatisSqlSessionFactoryChain(@Autowired DataSource dataSource)
        throws Exception {
        SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                                              .getResources(
                                                  "classpath*:config/mapper/com/petkit/ac/adaptor/chain/mapper/*.xml"));
        return sessionFactory.getObject();
    }

}

打包war包以部署在tomcat下

pom配置

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </dependency>

入口类

@SpringBootApplication
public class DemoApplication extends SpringBootServletInitializer {
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(DemoApplication.class);
    }

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

读取jar包外部配置文件

Spring-boot在启动时，如果不指定spring.config.location，将会从下面路径中依次加载application.properties中的属性:

• A /config subdirectory of the current directory. (即当前启动spring-boot程序文件夹的/config路径)
• The current directory(即当前启动spring-boot程序文件夹的./路径)
• A classpath /config package (当前jar/war包 classpath的/config路径)
• The classpath root (当前jar/war包 classpath的./路径)
  以上是优先级从大到小排序，高优先级的会覆盖低优先的值
  其中，如果激活了spring.profiles.active=xx，那么active的properties的优先级是最高的，所以如果使用外部文件配置，最好不要激活profiles

方法一

java -jar demo.jar --spring.config.location=/opt/dev/demo.properties
或者
java -Dspring.config.location=/opt/dev/demo.properties -jar demo.jar 

此时/opt/dev/demo.properties的优先级是最高的

方法二

@SpringBootApplication
@PropertySources({
    @PropertySource("classpath:application.properties"),
    // 引用外部配置文件，不会覆盖已有属性,file开头的优先级最低
    @PropertySource(value="file:${external.config}", ignoreResourceNotFound=true)
})
public class ChainBootApplication extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(ChainBootApplication.class);
    }

    public static void main(String[] args) {
        SpringApplication.run(ChainBootApplication.class, args);
    }
}