JAVA：Springboot动态装配Druid多数据源

1、简介

最近打算搭建一个鉴权中心服务，采用SpringBoot+Fastmybatis装配Druid，考虑后续拓展采用Druid多数据源配置，以一个数据源为主，多个动态数据源为辅的结构。除了数据库，后续会结合shiro安全框架来搭建。

2、引用

在pom.xml添加框架springboot +FastMybatis + Druid相关Maven引用。

<dependency>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-starter-WEB</artifactId></dependency><dependency>    <groupId>net.oschina.durcframework</groupId>    <artifactId>fastmybatis-spring-boot-starter</artifactId>    <version>${fastmybatis.version}</version></dependency><dependency>    <groupId>com.alibaba</groupId>    <artifactId>druid-spring-boot-starter</artifactId>    <version>${druid.version}</version></dependency><dependency>    <groupId>org.apache.shiro</groupId>    <artifactId>shiro-core</artifactId>    <version>${shiro.version}</version></dependency><dependency>    <groupId>org.apache.shiro</groupId>    <artifactId>shiro-spring</artifactId>    <version>${shiro.version}</version></dependency>

3、数据源队列

我们采用的是一个数据源为主，多个动态数据源为辅的结构，在后续添加新的数据源，我们只要调整新数据源配置就可以了，不用再改原来结构。所以我们要有自己的数据源队列来存储动态的数据源。

public class DynamicContextUtils {       private static final ThreadLocal<Deque<String>> CONTEXT = new ThreadLocal() {        @Override        protected Object initialValue() {            return new ArrayDeque();        }    };        public static String peek() {        return CONTEXT.get().peek();    }        public static void push(String dataSource) {        CONTEXT.get().push(dataSource);    }        public static void poll() {        Deque<String> deque = CONTEXT.get();        deque.poll();        if (deque.isEmpty()) {            CONTEXT.remove();        }    }}

4、数据源切面

首先我们要添加自己的annotion，并可以切面中可以拦截并加载动态数据源。

@Target({ElementType.METHOD, ElementType.TYPE})@Retention(RetentionPolicy.RUNTIME)@Documented@Inheritedpublic @interface DataSource {    String value() default "";}

现在我们在切面中拦截自己添加的annotion，然后通过@Aspect添加到我们定义的数据源队列中。

@Aspect@Component@Order(Ordered.HIGHEST_PRECEDENCE)public class DataSourceAspect {    protected Logger logger = LoggerFactory.getLogger(DataSourceAspect.class);    @Pointcut("@annotation(com.xhl.lk.auth2.datasource.annotation.DataSource)" +            "|| @within(com.xhl.lk.auth2.datasource.annotation.DataSource)")    public  void dataSourcePointCut(){    }    @Around("dataSourcePointCut()")    public  Object around(@NotNull ProceedingJoinPoint point) throws Throwable{        MethodSignature signature = (MethodSignature) point.getSignature();        Class targetClass = point.getTarget().getClass();        Method method = signature.getMethod();        DataSource targetDataSource = (DataSource) targetClass.getAnnotation(DataSource.class);        DataSource methodDataSource = method.getAnnotation(DataSource.class);        if(Objects.nonNull(targetDataSource) || Objects.nonNull(methodDataSource)){            String value = Objects.nonNull(methodDataSource) ? methodDataSource.value() : targetDataSource.value();            DynamicContextUtils.push(value);            logger.debug("set datasource is {}", value);        }        try{            return point.proceed();        }finally {            DynamicContextUtils.poll();            logger.info("clean datasource");        }    }}

5、数据源属性

添加Druid主数据源和动态数据源参数映射类，以便可以通过映射来调整和链接数据库。

@Datapublic class DataSourceProperty {    private String driverClassName;    private String url;    private String username;    private String passWord;        private int initialSize = 2;    private int maxActive = 10;    private int minIdle = -1;    private long maxWait = 60 * 1000L;    private long timeBetweenEvictionRunsMillis = 60 * 1000L;    private long minEvictableIdleTimeMillis = 1000L * 60L * 30L;    private long maxEvictableIdleTimeMillis = 1000L * 60L * 60L * 7;    private String validationQuery = "select 1";    private int validationQueryTimeout = -1;    private boolean testOnBorrow = false;    private boolean testOnReturn = false;    private boolean testWhileIdle = true;    private boolean poolPreparedStatements = false;    private int maxOpenPreparedStatements = -1;    private boolean sharePreparedStatements = false;    private String filters = "stat,wall";}

动态数据源属性以当前主数据源为主，从队列中获取。通过@ConfigurationProperties来标识动态数据源前缀。

@Data@ConfigurationProperties(prefix = "dynamic")public class DynamicDataSourceProperty {    private Map<String, DataSourceProperty> datasource = new LinkedHashMap<>();}

我们在配置文件application.yml定义多个数据源配置：

spring:    datasource:        type: com.alibaba.druid.pool.DruidDataSource        druid:            driver-class-name: com.Mysql.cj.jdbc.Driver            url: jdbc:mysql://192.168.254.128:3306/sys_xhl?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=Asia/Shanghai            username: shdxhl            password: shdxhl            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: 300000            #oracle需要打开注释            #validation-query: SELECT 1 FROM DUAL            #spring.datasource.druid.test-on-borrow=true            #spring.datasource.druid.test-while-idle=true            test-while-idle: true            test-on-borrow: true            test-on-return: false            stat-view-servlet:                enabled: true                url-pattern: /druid/*                #login-username: admin                #login-password: admin            filter:                stat:                    log-slow-sql: true                    slow-sql-millis: 1000                    merge-sql: false                wall:                    config:                        multi-statement-allow: true##多数据源的配置dynamic:  datasource:    slave1:        driver-class-name: com.mysql.cj.jdbc.Driver        url: jdbc:mysql://192.168.254.128:3306/blog_weike?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=Asia/Shanghai        username: blog        password: wiloveyou#    slave2:#      driver-class-name: org.postgresql.Driver#      url: jdbc:postgresql://localhost:5432/renren_security#      username: renren#      password: 123456

6、Config初始化

在@Configuration中实现主数据源和多个动态数据源数据链接初始化，同时通过继承AbstractRoutingDataSource来实现动态数据源切换。

//通过重载determineCurrentLookupKey 来获取切换的数据源Key。public class DynamicDataSource extends AbstractRoutingDataSource {    @Override    protected Object determineCurrentLookupKey() {        return DynamicContextUtils.peek();    }}

创建一个Dynamic数据源的Factory来实现动态数据源参数映射和Druid数据源初始化：

public class DynamicDataSourceFactory {    protected static Logger logger = LoggerFactory.getLogger(DynamicDataSourceFactory.class);    //build动态数据源，初始化    public static DruidDataSource buildDruidDataSource(DataSourceProperty properties) {        DruidDataSource druidDataSource = new DruidDataSource();        druidDataSource.setDriverClassName(properties.getDriverClassName());        druidDataSource.setUrl(properties.getUrl());        druidDataSource.setUsername(properties.getUsername());        druidDataSource.setPassword(properties.getPassword());        druidDataSource.setInitialSize(properties.getInitialSize());        druidDataSource.setMaxActive(properties.getMaxActive());        druidDataSource.setMinIdle(properties.getMinIdle());        druidDataSource.setMaxWait(properties.getMaxWait());        druidDataSource.setTimeBetweenEvictionRunsMillis(properties.getTimeBetweenEvictionRunsMillis());        druidDataSource.setMinEvictableIdleTimeMillis(properties.getMinEvictableIdleTimeMillis());        druidDataSource.setMaxEvictableIdleTimeMillis(properties.getMaxEvictableIdleTimeMillis());        druidDataSource.setValidationQuery(properties.getValidationQuery());        druidDataSource.setValidationQueryTimeout(properties.getValidationQueryTimeout());        druidDataSource.setTestOnBorrow(properties.isTestOnBorrow());        druidDataSource.setTestOnReturn(properties.isTestOnReturn());        druidDataSource.setPoolPreparedStatements(properties.isPoolPreparedStatements());        druidDataSource.setMaxOpenPreparedStatements(properties.getMaxOpenPreparedStatements());        druidDataSource.setSharePreparedStatements(properties.issharePreparedStatements());        try {            druidDataSource.setFilters(properties.getFilters());            druidDataSource.init();        } catch (SQLException e) {            logger.error("DynamicDataSourceFactory is error:" + e.toString());        }        return druidDataSource;    }}

最后我们在@Configuration添加多个数据源对象bean实例：

@Configuration@EnableConfigurationProperties(DynamicDataSourceProperty.class)public class DynamicDataSourceConfig {    @Autowired    private DynamicDataSourceProperty properties;    @Bean    @ConfigurationProperties(prefix = "spring.datasource.druid")    public DataSourceProperty dataSourceProperty() {        return new DataSourceProperty();    }    @Bean    public DynamicDataSource dynamicDataSource(DataSourceProperty dataSourceProperty) {        DynamicDataSource dynamicDataSource = new DynamicDataSource();        dynamicDataSource.setTargetDataSources(getDynamicDataSource());        //默认数据源        DruidDataSource defaultDataSource = DynamicDataSourceFactory.buildDruidDataSource(dataSourceProperty);        dynamicDataSource.setDefaultTargetDataSource(defaultDataSource);        return dynamicDataSource;    }    private Map<Object, Object> getDynamicDataSource(){        Map<String, DataSourceProperty> dataSourcePropertyMap = properties.getDatasource();        Map<Object, Object> targetDataSources = new ConcurrentHashMap<>(dataSourcePropertyMap.size());        dataSourcePropertyMap.forEach((k, v) -> {            DruidDataSource druidDataSource = DynamicDataSourceFactory.buildDruidDataSource(v);            targetDataSources.put(k, druidDataSource);        });        return targetDataSources;    }}

7、验证

最后我们可以很轻松的验证当前Druid多数据源配置是否生效，通过访问Http://localhost:8080/lk-auth/druid/的地址，可以很清楚的看到数据库执行语句和数据源的各种指标。代码链接：https://gitee.com/lhdxhl/lk-auth.git

来源地址：https://blog.csdn.net/lishangke/article/details/131298271