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目录

?开发步骤?测试?自定义启动器?启动器支持多Druid和C3P0

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?开发步骤

1.创建启动器项目

添加启动器相关依赖创建属性配置类创建自动配置类编写自动配置文件(spring.factories)使用自定义的启动器

?测试

创建个SpringBoot项目，导入依赖

<parent>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-starter-parent</artifactId>    <version>2.2.2.RELEASE</version></parent><properties>    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>    <java.version>1.8</java.version></properties><dependencies>    <!--引入spring‐boot‐starter；所有starter的基本配置-->    <dependency>        <groupId>org.springframework.boot</groupId>        <artifactId>spring-boot-starter</artifactId></dependency>    <!--自动配置连接池-->    <dependency>        <groupId>com.alibaba</groupId>        <artifactId>druid</artifactId>        <version>1.1.12</version></dependency>    <dependency>            <groupId>c3p0</groupId>            <artifactId>c3p0</artifactId>            <version>0.9.1.2</version></dependency>    <dependency>        <groupId>org.springframework.boot</groupId>        <artifactId>spring-boot-configuration-processor</artifactId>        <optional>true</optional>    </dependency></dependencies>

创建属性配置类

@Component@ConfigurationProperties(prefix = "spring.jdbc.datasource")public class DataSourceProperties {    private String driverClassName ;    private String url;    private String username;    private String password;    public String getDriverClassName() {        return driverClassName;    }    public void setDriverClassName(String driverClassName) {        this.driverClassName = driverClassName;    }    public String getUrl() {        return url;    }    public void setUrl(String url) {        this.url = url;    }    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    public String getPassword() {        return password;    }    public void setPassword(String password) {        this.password = password;    }    @Override    public String toString() {        return "DataSourceProperties{" +                "driverClassName='" + driverClassName + '\'' +                ", url='" + url + '\'' +                ", username='" + username + '\'' +                ", password='" + password + '\'' +                '}';    }}

创建自动配置类

@SpringBootConfiguration  //当前类是个配置类@EnableConfigurationProperties(DataSourceProperties.class)public class DataSourceAutoConfiguration {    @Autowired    private DataSourceProperties dataSourceProperties;   @Bean    public DataSource createDataSource(){        DruidDataSource dataSource = new DruidDataSource();        dataSource.setDriverClassName(dataSourceProperties.getDriverClassName());        dataSource.setUrl(dataSourceProperties.getUrl());        dataSource.setUsername(dataSourceProperties.getUsername());        dataSource.setPassword(dataSourceProperties.getPassword());        return dataSource;    }}

编写自动配置属性文件在 resource 文件夹下面新建 META-INF/spring.factories

org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.study.config.DataSourceAutoConfiguration

执行install , 安装项目

?自定义启动器

重新创建个项目，引用SpringBoot_datasource的依赖

<!--依赖自定义启动器--><dependency><groupId>com.study</groupId><artifactId>SpringBoot_datasource</artifactId><version>1.0-SNAPSHOT</version></dependency>

配置连接池信息

server.port=8081spring.jdbc.datasource.driverClassName=com.mysql.jdbc.Driverspring.jdbc.datasource.url=jdbc:mysql:///springboot_datasourcespring.jdbc.datasource.username=rootspring.jdbc.datasource.password=rootspring.profiles.active=datasource

编写Controller类

@RestControllerpublic class HelloAutoController {    @Autowired    private DataSource dataSource;    @RequestMapping("/dataSource")    public String dataSource() {        System.out.println(dataSource.getClass());//打印DruidDataSource数据源        return "Hello dataSource! ! ! " ;    }}

使用自定义启动类进行测试

?启动器支持多Druid和C3P0

添加创建druid和c3p0方法

@SpringBootConfiguration  //当前类是个配置类@EnableConfigurationProperties(DataSourceProperties.class)public class DataSourceAutoConfiguration {    @Autowired    private DataSourceProperties dataSourceProperties;    @Bean    @ConditionalOnProperty(value = "spring.jdbc.datasource.type",havingValue = "druid")    public DataSource createDataSource(){        DruidDataSource dataSource = new DruidDataSource();        dataSource.setDriverClassName(dataSourceProperties.getDriverClassName());        dataSource.setUrl(dataSourceProperties.getUrl());        dataSource.setUsername(dataSourceProperties.getUsername());        dataSource.setPassword(dataSourceProperties.getPassword());        return dataSource;    }    @Bean    @ConditionalOnProperty(value = "spring.jdbc.datasource.type",havingValue = "c3p0")    public DataSource createC3P0DataSource() throws Exception {        ComboPooledDataSource dataSource = new ComboPooledDataSource();        dataSource.setDriverClass(dataSourceProperties.getDriverClassName());        dataSource.setJdbcUrl(dataSourceProperties.getUrl());        dataSource.setUser(dataSourceProperties.getUsername());        dataSource.setPassword(dataSourceProperties.getPassword());        return dataSource;    }}

配置文件中配置了spring.jdbc.datasource.type=druid使用druid数据源

server.port=8081spring.jdbc.datasource.driverClassName=com.mysql.jdbc.Driverspring.jdbc.datasource.url=jdbc:mysql:///springboot_datasourcespring.jdbc.datasource.username=rootspring.jdbc.datasource.password=rootspring.jdbc.datasource.type=druid

重新安装，再次测试

配置了spring.jdbc.datasource.type=c3p0使用c3p0数据源

server.port=8081spring.jdbc.datasource.driverClassName=com.mysql.jdbc.Driverspring.jdbc.datasource.url=jdbc:mysql:///springboot_datasourcespring.jdbc.datasource.username=rootspring.jdbc.datasource.password=rootspring.jdbc.datasource.type=c3p0

重新安装，再次测试