一、数据源装配
通过查看代码可知，默认已装配了数据源和JdbcTemplate
System.out.println(context.getBean(DataSource.class)); System.out.println(context.getBean(JdbcTemplate.class));
1.1、环境搭建
主要是pom引用：spring-boot-starter-jdbc、增加数据库驱动
<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 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.lhx.spring</groupId><artifactId>springboot-web</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>springboot-web</name><url>http://maven.apache.org</url><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><maven.compiler.target>1.8</maven.compiler.target><maven.compiler.source>1.8</maven.compiler.source></properties><dependencyManagement><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-dependencies</artifactId><version>1.5.9.RELEASE</version><type>pom</type><scope>import</scope></dependency></dependencies></dependencyManagement><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId></dependency></dependencies> </project>
查看spring-boot-autoconfigure-1.5.9.RELEASE.jar包下的org.springframework.boot.autoconfigure.jdbc下的DataSourceProperties其实所有的都是类似的配置
@ConfigurationProperties(prefix = "spring.datasource") public class DataSourcePropertiesimplements BeanClassLoaderAware, EnvironmentAware, InitializingBean {
可以看到默认读取spring.datasource开头的配置。
1.2、配置
spring.datasource.driverClassName=com.mysql.jdbc.Driver spring.datasource.url=jdbc:mysql://127.0.0.1:3306/springboot spring.datasource.username=root spring.datasource.password=root
1.3、使用
public static void main(String[] args) throws SQLException {ConfigurableApplicationContext context = SpringApplication.run(App.class, args);dataSource = context.getBean(DataSource.class);Connection connection = dataSource.getConnection();System.out.println(connection.getCatalog());}
二、JdbcTemplate
在配置好基本配置后，JdbcTemplate就可以使用了
@Repository public class ProductDao {@Autowiredprivate JdbcTemplate jdbcTemplate;public void addProdcut(String value) {String sql = "insert into product(pname) values('" + value + "')";jdbcTemplate.execute(sql);} }
调用
public class App {public static void main(String[] args) throws SQLException {ConfigurableApplicationContext context = SpringApplication.run(App.class, args);context.getBean(ProductDao.class).addProdcut("mp3");connection.close();} }
三、切换数据源
System.out.println(context.getBean(DataSource.class)); 查看到使用的是默认提供的：org.apache.tomcat.jdbc.pool.DataSource数据源
方式一、排除添加切换
1》排除掉tomcat-jdbc
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId><exclusions><exclusion><groupId>org.apache.tomcat</groupId><artifactId>tomcat-jdbc</artifactId></exclusion></exclusions></dependency>
2》添加新的数据源
<dependency><groupId>com.zaxxer</groupId><artifactId>HikariCP</artifactId></dependency>
方式二、type配置数据源切换
3.2.1、原理查看
查看spring-boot-autoconfigure-1.5.9.RELEASE.jar包下的org.springframework.boot.autoconfigure.jdbc下的DataSourceProperties的配置
使用type指定【private Class<? extends DataSource> type;】在application.properties中
spring.datasource.type=com.zaxxer.hikari.HikariDataSource
默认支持以下几种数据源类型，查看spring-boot-autoconfigure-1.5.9.RELEASE.jar包下的org.springframework.boot.autoconfigure.jdbc下的DataSourceAutoConfiguration
DataSourceConfiguration.Tomcat.class DataSourceConfiguration.Hikari.class DataSourceConfiguration.Dbcp.class DataSourceConfiguration.Dbcp2.class DataSourceConfiguration.Generic.class
3.2.2、具体步骤
1》添加对应数据源pom
<dependency><groupId>com.zaxxer</groupId><artifactId>HikariCP</artifactId></dependency>
2》使用配置
spring.datasource.type=com.zaxxer.hikari.HikariDataSource
3.3、配置自定义数据源
1》添加POM依赖
<dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.6</version></dependency>
2》、增加DBConfiguration配置类
package com.lhx.spring.springboot_web;import javax.sql.DataSource;import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.SpringBootConfiguration; import org.springframework.context.annotation.Bean; import org.springframework.core.env.Environment;import com.alibaba.druid.pool.DruidDataSource;@SpringBootConfiguration public class DBConfiguration {@Autowiredprivate Environment env;@Beanpublic DataSource createDataSource() {DruidDataSource source = new DruidDataSource();source.setUrl(env.getProperty("spring.datasource.url"));source.setUsername(env.getProperty("spring.datasource.username"));source.setPassword(env.getProperty("spring.datasource.password"));source.setDriverClassName(env.getProperty("spring.datasource.driverClassName"));return source;} }
四、事务
4.1、配置开启
1、在入口app增加注解
@EnableTransactionManagement
2、在需要事务的公有方法上添加注解
@Transactional
示例
@Transactionalpublic void addProdcutBatch(String... names) throws Exception {for (String name : names) {String sql = "insert into product(pname) values('" + name + "')";jdbcTemplate.execute(sql);if ("".equals("")) {throw new NullPointerException();}}}
注意：spring事务，默认支持运行时异常，即RunTimeException，非运行时异常不会回滚
4.2、设置针对哪些异常使用事务
默认是运行时
设置所有异常
@Transactional(rollbackFor=Exception.class) 设置哪些异常不回滚
@Transactional(noRollbackFor=NullPointerException.class)
注意点：
1、要想使用事务生效，被调用的方法必须有Transactional 注解，对于内部调用方法有无注解无影响
2、需要数据库支持事务。
