spring boot datasource

application-database.properties

#初始化数据库的时候，如果错误，是否继续启动。spring.datasource.continue-on-error=false#jdbc driver.默认通过uri来自动检测。spring.datasource.driver-class-name=com.mysql.jdbc.Driver#使用的db名称spring.datasource.name=test#是否随机生成db名称spring.datasource.generate-unique-name=false#jdbc url.连接数据库的urispring.datasource.url=#数据库连接用户名spring.datasource.username=#数据连接密码spring.datasource.password=#DML的用户名(如果数据库专门设置了对应的用户名和密码)spring.datasource.data-username=#DML的密码(如果数据库专门设置了对应的用户名和密码)spring.datasource.data-password=#DDL的用户名(如果数据库专门设置了对应的用户名和密码)spring.datasource.schema-username=#DDL的密码(如果数据库专门设置了对应的用户名和密码)spring.datasource.schema-password=#全限定名，连接池。默认自动检测classpathspring.datasource.type=com.zaxxer.hikari.HikariDataSource#sql脚本字符spring.datasource.sql-script-encoding=UTF-8#sql脚本分割符，默认为分号。spring.datasource.separator=;#dbcp2的连接参数spring.datasource.dbcp2.*#hikari的连接参数spring.datasource.hikari.*#tomcat的连接参数spring.datasource.tomcat.*

源码-DataSourceProperties
加载对应的spring.datasource配置参数。

@ConfigurationProperties(prefix = "spring.datasource")public class DataSourceProperties implements BeanClassLoaderAware, InitializingBean {    private ClassLoader classLoader;    /**     * Name of the datasource. Default to "testdb" when using an embedded database.     */    private String name;    /**     * Whether to generate a random datasource name.     */    private boolean generateUniqueName;    /**     * Fully qualified name of the connection pool implementation to use. By default, it     * is auto-detected from the classpath.     */    private Class type;    /**     * Fully qualified name of the JDBC driver. Auto-detected based on the URL by default.     */    private String driverClassName;    /**     * JDBC URL of the database.     */    private String url;    /**     * Login username of the database.     */    private String username;    /**     * Login password of the database.     */    private String password;    /**     * JNDI location of the datasource. Class, url, username & password are ignored when     * set.     */    private String jndiName;    /**     * Initialize the datasource with available DDL and DML scripts.     */    private DataSourceInitializationMode initializationMode = DataSourceInitializationMode.EMBEDDED;    /**     * Platform to use in the DDL or DML scripts (such as schema-${platform}.sql or     * data-${platform}.sql).     */    private String platform = "all";    /**     * Schema (DDL) script resource references.     */    private List schema;    /**     * Username of the database to execute DDL scripts (if different).     */    private String schemaUsername;    /**     * Password of the database to execute DDL scripts (if different).     */    private String schemaPassword;    /**     * Data (DML) script resource references.     */    private List data;    /**     * Username of the database to execute DML scripts (if different).     */    private String dataUsername;    /**     * Password of the database to execute DML scripts (if different).     */    private String dataPassword;    /**     * Whether to stop if an error occurs while initializing the database.     */    private boolean continueOnError = false;    /**     * Statement separator in SQL initialization scripts.     */    private String separator = ";";    /**     * SQL scripts encoding.     */    private Charset sqlScriptEncoding;    private EmbeddedDatabaseConnection embeddedDatabaseConnection = EmbeddedDatabaseConnection.NONE;    private Xa xa = new Xa();    private String uniqueName;

源码-DataSourceAutoConfiguration
自动装配dataSource。根据DataSourceProperties参数。

@Configuration@ConditionalOnClass({ DataSource.class, EmbeddedDatabaseType.class })@EnableConfigurationProperties(DataSourceProperties.class)@Import({ DataSourcePoolMetadataProvidersConfiguration.class,        DataSourceInitializationConfiguration.class })public class DataSourceAutoConfiguration {    @Configuration    @Conditional(EmbeddedDatabaseCondition.class)    @ConditionalOnMissingBean({ DataSource.class, XADataSource.class })    @Import(EmbeddedDataSourceConfiguration.class)    protected static class EmbeddedDatabaseConfiguration {    }    @Configuration    @Conditional(PooledDataSourceCondition.class)    @ConditionalOnMissingBean({ DataSource.class, XADataSource.class })    @Import({ DataSourceConfiguration.Hikari.class, DataSourceConfiguration.Tomcat.class,            DataSourceConfiguration.Dbcp2.class, DataSourceConfiguration.Generic.class,            DataSourceJmxConfiguration.class })    protected static class PooledDataSourceConfiguration {    }    /**     * {@link AnyNestedCondition} that checks that either {@code spring.datasource.type}     * is set or {@link PooledDataSourceAvailableCondition} applies.     */    static class PooledDataSourceCondition extends AnyNestedCondition {        PooledDataSourceCondition() {            super(ConfigurationPhase.PARSE_CONFIGURATION);        }        @ConditionalOnProperty(prefix = "spring.datasource", name = "type")        static class ExplicitType {        }        @Conditional(PooledDataSourceAvailableCondition.class)        static class PooledDataSourceAvailable {        }    }    /**     * {@link Condition} to test if a supported connection pool is available.     */    static class PooledDataSourceAvailableCondition extends SpringBootCondition {        @Override        public ConditionOutcome getMatchOutcome(ConditionContext context,                AnnotatedTypeMetadata metadata) {            ConditionMessage.Builder message = ConditionMessage                    .forCondition("PooledDataSource");            if (getDataSourceClassLoader(context) != null) {                return ConditionOutcome                        .match(message.foundExactly("supported DataSource"));            }            return ConditionOutcome                    .noMatch(message.didNotFind("supported DataSource").atAll());        }        /**         * Returns the class loader for the {@link DataSource} class. Used to ensure that         * the driver class can actually be loaded by the data source.         * @param context the condition context         * @return the class loader         */        private ClassLoader getDataSourceClassLoader(ConditionContext context) {            Class dataSourceClass = DataSourceBuilder                    .findType(context.getClassLoader());            return (dataSourceClass == null ? null : dataSourceClass.getClassLoader());        }    }    /**     * {@link Condition} to detect when an embedded {@link DataSource} type can be used.     * If a pooled {@link DataSource} is available, it will always be preferred to an     * {@code EmbeddedDatabase}.     */    static class EmbeddedDatabaseCondition extends SpringBootCondition {        private final SpringBootCondition pooledCondition = new PooledDataSourceCondition();        @Override        public ConditionOutcome getMatchOutcome(ConditionContext context,                AnnotatedTypeMetadata metadata) {            ConditionMessage.Builder message = ConditionMessage                    .forCondition("EmbeddedDataSource");            if (anyMatches(context, metadata, this.pooledCondition)) {                return ConditionOutcome                        .noMatch(message.foundExactly("supported pooled data source"));            }            EmbeddedDatabaseType type = EmbeddedDatabaseConnection                    .get(context.getClassLoader()).getType();            if (type == null) {                return ConditionOutcome                        .noMatch(message.didNotFind("embedded database").atAll());            }            return ConditionOutcome.match(message.found("embedded database").items(type));        }    }}

测试

@RunWith(SpringRunner.class)@SpringBootTestpublic class AppContextTest {    @Qualifier("dataSource")    @Autowired    private DataSource dataSource;      @Test    public void dataSourceTest() throws SQLException {        Connection connection = null;        try {            connection = dataSource.getConnection();            int transactionIsolation = connection.getTransactionIsolation();            String schema = connection.getSchema();            System.out.println("transactionIsolation="+transactionIsolation+";schema="+schema);        } catch (SQLException e) {            e.printStackTrace();        }finally {            if (null != connection)                connection.close();        }    }

spring boot默认采用HikariDataSource数据库连接池。

druid数据库连接池:https://blog.51cto.com/881206524/2121687