m

dynamic_datasource_demo/pom.xml

@@ -0,0 +1,60 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.6.6</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+    <groupId>org.javaboy</groupId>
+    <artifactId>dynamic_datasource_demo</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>dynamic_datasource_demo</name>
+    <description>Demo project for Spring Boot</description>
+    <properties>
+        <java.version>11</java.version>
+    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-aop</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.mybatis.spring.boot</groupId>
+            <artifactId>mybatis-spring-boot-starter</artifactId>
+            <version>2.2.2</version>
+        </dependency>
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>druid-spring-boot-starter</artifactId>
+            <version>1.2.9</version>
+        </dependency>
+
+        <dependency>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

dynamic_datasource_demo/src/main/java/org/javaboy/demo/DynamicDatasourceDemoApplication.java

@@ -0,0 +1,13 @@
+package org.javaboy.demo;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class DynamicDatasourceDemoApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(DynamicDatasourceDemoApplication.class, args);
+    }
+
+}

dynamic_datasource_demo/src/main/java/org/javaboy/demo/annotation/DataSource.java

@@ -0,0 +1,27 @@
+package org.javaboy.demo.annotation;
+
+import org.javaboy.demo.provider.DynamicDataSourceProvider;
+import org.springframework.core.annotation.AliasFor;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * @author 江南一点雨
+ * @微信公众号 江南一点雨
+ * @网站 http://www.itboyhub.com
+ * @国际站 http://www.javaboy.org
+ * @微信 a_java_boy
+ * @GitHub https://github.com/lenve
+ * @Gitee https://gitee.com/lenve
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.METHOD, ElementType.TYPE})
+public @interface DataSource {
+    String dataSourceName() default DynamicDataSourceProvider.DEFAULT_DATASOURCE;
+
+    @AliasFor("dataSourceName")
+    String value() default DynamicDataSourceProvider.DEFAULT_DATASOURCE;
+}

dynamic_datasource_demo/src/main/java/org/javaboy/demo/aspect/DataSourceAspect.java

@@ -0,0 +1,63 @@
+package org.javaboy.demo.aspect;
+
+import org.aspectj.lang.ProceedingJoinPoint;
+import org.aspectj.lang.annotation.Around;
+import org.aspectj.lang.annotation.Aspect;
+import org.aspectj.lang.annotation.Pointcut;
+import org.aspectj.lang.reflect.MethodSignature;
+import org.javaboy.demo.annotation.DataSource;
+import org.javaboy.demo.dynamic.DynamicDataSourceContextHolder;
+import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.core.annotation.Order;
+import org.springframework.stereotype.Component;
+import org.springframework.util.ObjectUtils;
+
+import java.util.Objects;
+
+/**
+ * @author 江南一点雨
+ * @微信公众号 江南一点雨
+ * @网站 http://www.itboyhub.com
+ * @国际站 http://www.javaboy.org
+ * @微信 a_java_boy
+ * @GitHub https://github.com/lenve
+ * @Gitee https://gitee.com/lenve
+ */
+@Aspect
+@Order(1)
+@Component
+public class DataSourceAspect {
+    @Pointcut("@annotation(org.javaboy.demo.annotation.DataSource)"
+            + "|| @within(org.javaboy.demo.annotation.DataSource)")
+    public void dsPc() {
+
+    }
+
+    @Around("dsPc()")
+    public Object around(ProceedingJoinPoint point) throws Throwable {
+        DataSource dataSource = getDataSource(point);
+
+        if (Objects.nonNull(dataSource)) {
+            DynamicDataSourceContextHolder.setDataSourceType(dataSource.dataSourceName());
+        }
+
+        try {
+            return point.proceed();
+        } finally {
+            // 销毁数据源 在执行方法之后
+            DynamicDataSourceContextHolder.clearDataSourceType();
+        }
+    }
+
+    /**
+     * 获取需要切换的数据源
+     */
+    public DataSource getDataSource(ProceedingJoinPoint point) {
+        MethodSignature signature = (MethodSignature) point.getSignature();
+        DataSource dataSource = AnnotationUtils.findAnnotation(signature.getMethod(), DataSource.class);
+        if (Objects.nonNull(dataSource)) {
+            return dataSource;
+        }
+        return AnnotationUtils.findAnnotation(signature.getDeclaringType(), DataSource.class);
+    }
+}

dynamic_datasource_demo/src/main/java/org/javaboy/demo/config/DruidAutoConfiguration.java

@@ -0,0 +1,72 @@
+package org.javaboy.demo.config;
+
+import com.alibaba.druid.spring.boot.autoconfigure.properties.DruidStatProperties;
+import com.alibaba.druid.util.Utils;
+import org.javaboy.demo.dynamic.DynamicDataSource;
+import org.javaboy.demo.provider.DynamicDataSourceProvider;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.web.servlet.FilterRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import javax.servlet.*;
+import java.io.IOException;
+
+/**
+ * @author 江南一点雨
+ * @微信公众号 江南一点雨
+ * @网站 http://www.itboyhub.com
+ * @国际站 http://www.javaboy.org
+ * @微信 a_java_boy
+ * @GitHub https://github.com/lenve
+ * @Gitee https://gitee.com/lenve
+ */
+@Configuration
+public class DruidAutoConfiguration {
+    @Autowired
+    DynamicDataSourceProvider dynamicDataSourceProvider;
+
+    @Bean
+    DynamicDataSource dynamicDataSource() {
+        return new DynamicDataSource(dynamicDataSourceProvider);
+    }
+
+    /**
+     * 去除数据源监控页面的广告
+     *
+     * @param properties
+     * @return
+     */
+    @Bean
+    @ConditionalOnProperty(name = "spring.datasource.druid.statViewServlet.enabled", havingValue = "true")
+    public FilterRegistrationBean removeDruidFilterRegistrationBean(DruidStatProperties properties) {
+        // 获取web监控页面的参数
+        DruidStatProperties.StatViewServlet config = properties.getStatViewServlet();
+        // 提取common.js的配置路径
+        String pattern = config.getUrlPattern() != null ? config.getUrlPattern() : "/druid/*";
+        String commonJsPattern = pattern.replaceAll("\\*", "js/common.js");
+        // 创建filter进行过滤
+        Filter filter = new Filter() {
+            @Override
+            public void init(javax.servlet.FilterConfig filterConfig) throws ServletException {
+            }
+
+            @Override
+            public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
+                    throws IOException, ServletException {
+                String text = Utils.readFromResource("support/http/resources/js/common.js");
+                text = text.replace("this.buildFooter();", "");
+                response.getWriter().write(text);
+            }
+
+            @Override
+            public void destroy() {
+            }
+        };
+        FilterRegistrationBean registrationBean = new FilterRegistrationBean();
+        registrationBean.setFilter(filter);
+        registrationBean.addUrlPatterns(commonJsPattern);
+        return registrationBean;
+    }
+}

dynamic_datasource_demo/src/main/java/org/javaboy/demo/dynamic/DynamicDataSource.java

@@ -0,0 +1,35 @@
+package org.javaboy.demo.dynamic;
+
+import org.javaboy.demo.provider.DynamicDataSourceProvider;
+import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * @author 江南一点雨
+ * @微信公众号 江南一点雨
+ * @网站 http://www.itboyhub.com
+ * @国际站 http://www.javaboy.org
+ * @微信 a_java_boy
+ * @GitHub https://github.com/lenve
+ * @Gitee https://gitee.com/lenve
+ */
+public class DynamicDataSource extends AbstractRoutingDataSource {
+
+    DynamicDataSourceProvider dynamicDataSourceProvider;
+
+    public DynamicDataSource(DynamicDataSourceProvider dynamicDataSourceProvider) {
+        this.dynamicDataSourceProvider = dynamicDataSourceProvider;
+        Map<Object, Object> targetDataSources = new HashMap<>(dynamicDataSourceProvider.loadDataSources());
+        super.setTargetDataSources(targetDataSources);
+        super.setDefaultTargetDataSource(dynamicDataSourceProvider.loadDataSources().get(DynamicDataSourceProvider.DEFAULT_DATASOURCE));
+        super.afterPropertiesSet();
+    }
+
+    @Override
+    protected Object determineCurrentLookupKey() {
+        String dataSourceType = DynamicDataSourceContextHolder.getDataSourceType();
+        return dataSourceType;
+    }
+}

dynamic_datasource_demo/src/main/java/org/javaboy/demo/dynamic/DynamicDataSourceContextHolder.java

@@ -0,0 +1,45 @@
+package org.javaboy.demo.dynamic;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * @author 江南一点雨
+ * @微信公众号 江南一点雨
+ * @网站 http://www.itboyhub.com
+ * @国际站 http://www.javaboy.org
+ * @微信 a_java_boy
+ * @GitHub https://github.com/lenve
+ * @Gitee https://gitee.com/lenve
+ */
+public class DynamicDataSourceContextHolder {
+    public static final Logger log = LoggerFactory.getLogger(DynamicDataSourceContextHolder.class);
+
+    /**
+     * 使用ThreadLocal维护变量，ThreadLocal为每个使用该变量的线程提供独立的变量副本，
+     * 所以每一个线程都可以独立地改变自己的副本，而不会影响其它线程所对应的副本。
+     */
+    private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>();
+
+    /**
+     * 设置数据源的变量
+     */
+    public static void setDataSourceType(String dsType) {
+        log.info("切换到{}数据源", dsType);
+        CONTEXT_HOLDER.set(dsType);
+    }
+
+    /**
+     * 获得数据源的变量
+     */
+    public static String getDataSourceType() {
+        return CONTEXT_HOLDER.get();
+    }
+
+    /**
+     * 清空数据源变量
+     */
+    public static void clearDataSourceType() {
+        CONTEXT_HOLDER.remove();
+    }
+}

dynamic_datasource_demo/src/main/java/org/javaboy/demo/mapper/UserMapper.java

@@ -0,0 +1,20 @@
+package org.javaboy.demo.mapper;
+
+import org.apache.ibatis.annotations.Insert;
+import org.apache.ibatis.annotations.Mapper;
+import org.apache.ibatis.annotations.Select;
+
+/**
+ * @author 江南一点雨
+ * @微信公众号 江南一点雨
+ * @网站 http://www.itboyhub.com
+ * @国际站 http://www.javaboy.org
+ * @微信 a_java_boy
+ * @GitHub https://github.com/lenve
+ * @Gitee https://gitee.com/lenve
+ */
+@Mapper
+public interface UserMapper {
+    @Select("select count(*) from user")
+    Integer count();
+}