SpringBoot学习---第五篇：动态数据源（多数据源自动切换）

目录

一、应用场景

二、准备工作

2.1  创建数据表

2.2 添加依赖

2.3 生成 bean、dao、mapper

三、动态数据源

3.1 配置文件 application.properties

3.2 动态数据源核心代码

3.3 启动类添加注解

四、使用方法

4.1 Controller

4.2 Service

五、测试

六、Springboot2.0动态多数据源切换

一、应用场景

项目需要从自己的数据库上读取和管理数据外，还有一部分业务涉及到其他多个数据库。

为了能够灵活地指定具体的数据库，本文基于注解和AOP的方法实现多数据源自动切换。在使用过程中，只需要添加注解就可以使用，简单方便。

二、准备工作

2.1  创建数据表

1.  
   USE test;
2.  
   CREATE TABLE `user` (
3.  
   `id` int(11) NOT NULL AUTO_INCREMENT,
4.  
   `name` varchar(255) NOT NULL,
5.  
   `age` int(11) NOT NULL,
6.  
   PRIMARY KEY (`id`)
7.  
   ) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8
8.  
    
9.  
    
10.  
    USE test1;
11.  
    CREATE TABLE `teacher` (
12.  
    `tid` int(11) NOT NULL AUTO_INCREMENT,
13.  
    `tname` varchar(255) NOT NULL,
14.  
    `tage` int(11) NOT NULL,
15.  
    PRIMARY KEY (`tid`)
16.  
    ) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8
17.  
     
18.  
     
19.  
     
20.  
    USE test2;
21.  
    CREATE TABLE `student` (
22.  
    `sid` int(11) NOT NULL AUTO_INCREMENT,
23.  
    `sname` varchar(255) NOT NULL,
24.  
    `sage` int(11) NOT NULL,
25.  
    PRIMARY KEY (`sid`)
26.  
    ) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8

2.2 添加依赖

spring boot：1.5.8.RELEASE

mysql：5.1.44

mybatis:1.3.2

druid:1.1.3

1.  
   <?xml version="1.0" encoding="UTF-8"?>
2.  
   <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
3.  
   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
4.  
   <modelVersion>4.0.0</modelVersion>
5.  
    
6.  
   <groupId>com.example</groupId>
7.  
   <artifactId>dynamic-data-source</artifactId>
8.  
   <version>0.0.1-SNAPSHOT</version>
9.  
   <packaging>jar</packaging>
10.  
     
11.  
    <name>dynamic-data-source</name>
12.  
    <description>Demo project for Spring Boot</description>
13.  
     
14.  
    <parent>
15.  
    <groupId>org.springframework.boot</groupId>
16.  
    <artifactId>spring-boot-starter-parent</artifactId>
17.  
    <version>1.5.8.RELEASE</version>
18.  
    <relativePath/> <!-- lookup parent from repository -->
19.  
    </parent>
20.  
     
21.  
    <properties>
22.  
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
23.  
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
24.  
    <java.version>1.8</java.version>
25.  
    </properties>
26.  
     
27.  
    <dependencies>
28.  
    <dependency>
29.  
    <groupId>org.springframework.boot</groupId>
30.  
    <artifactId>spring-boot-starter-web</artifactId>
31.  
    </dependency>
32.  
     
33.  
    <!--mysql-->
34.  
    <dependency>
35.  
    <groupId>mysql</groupId>
36.  
    <artifactId>mysql-connector-java</artifactId>
37.  
    <scope>runtime</scope>
38.  
    </dependency>
39.  
    <!--mybatis-->
40.  
    <dependency>
41.  
    <groupId>org.mybatis.spring.boot</groupId>
42.  
    <artifactId>mybatis-spring-boot-starter</artifactId>
43.  
    <version>1.3.2</version>
44.  
    </dependency>
45.  
    <!--aop-->
46.  
    <dependency>
47.  
    <groupId>org.springframework.boot</groupId>
48.  
    <artifactId>spring-boot-starter-aop</artifactId>
49.  
    </dependency>
50.  
    <!--数据库连接池-->
51.  
    <dependency>
52.  
    <groupId>com.alibaba</groupId>
53.  
    <artifactId>druid</artifactId>
54.  
    <version>1.1.3</version>
55.  
    </dependency>
56.  
     
57.  
    <dependency>
58.  
    <groupId>org.springframework.boot</groupId>
59.  
    <artifactId>spring-boot-starter-test</artifactId>
60.  
    <scope>test</scope>
61.  
    </dependency>
62.  
    </dependencies>
63.  
     
64.  
    <build>
65.  
    <plugins>
66.  
    <plugin>
67.  
    <groupId>org.springframework.boot</groupId>
68.  
    <artifactId>spring-boot-maven-plugin</artifactId>
69.  
    </plugin>
70.  
    <!-- mybatis generator 自动生成代码插件 -->
71.  
    <plugin>
72.  
    <groupId>org.mybatis.generator</groupId>
73.  
    <artifactId>mybatis-generator-maven-plugin</artifactId>
74.  
    <version>1.3.2</version>
75.  
    <configuration>
76.  
    <overwrite>true</overwrite>
77.  
    <verbose>true</verbose>
78.  
    </configuration>
79.  
    </plugin>
80.  
    </plugins>
81.  
    </build>
82.  
    </project>

2.3 生成 bean、dao、mapper

使用MyBatis Generator自动生成，方法如下：https://blog.csdn.net/cllaure/article/details/81483858

三、动态数据源

3.1 配置文件 application.properties

1.  
   custom.datasource.defaultname=default
2.  
   custom.datasource.names=ds1,ds2
3.  
    
4.  
   # 默认数据源
5.  
   custom.datasource.driver-class-name=com.mysql.jdbc.Driver
6.  
   custom.datasource.url=jdbc:mysql://localhost:3306/test
7.  
   custom.datasource.username=root
8.  
   custom.datasource.password=root
9.  
    
10.  
    # 更多数据源
11.  
    custom.datasource.ds1.driver-class-name=com.mysql.jdbc.Driver
12.  
    custom.datasource.ds1.url=jdbc:mysql://localhost:3306/test1
13.  
    custom.datasource.ds1.username=root
14.  
    custom.datasource.ds1.password=root
15.  
     
16.  
    custom.datasource.ds2.driver-class-name=com.mysql.jdbc.Driver
17.  
    custom.datasource.ds2.url=jdbc:mysql://localhost:3306/test2
18.  
    custom.datasource.ds2.username=root
19.  
    custom.datasource.ds2.password=root
20.  
     
21.  
     
22.  
    custom.datasource.filters=stat
23.  
    custom.datasource.maxActive=100
24.  
    custom.datasource.initialSize=1
25.  
    custom.datasource.minIdle=1
26.  
    custom.datasource.timeBetweenEvictionRunsMillis=60000
27.  
    custom.datasource.minEvictableIdleTimeMillis=300000
28.  
    custom.datasource.validationQuery=select 'x'
29.  
    custom.datasource.testWhileIdle=true
30.  
    custom.datasource.testOnBorrow=false
31.  
    custom.datasource.testOnReturn=false
32.  
    custom.datasource.poolPreparedStatements=true
33.  
    custom.datasource.maxOpenPreparedStatements=100
34.  
     
35.  
    mybatis.type-aliases-package=com.example.demo.model.*
36.  
    mybatis.mapper-locations=classpath:mapper/**/*.xml

3.2 动态数据源核心代码

1.  
   DynamicDataSource：动态数据源切换；
2.  
   DynamicDataSourceAspect：利用AOP切面实现数据源的动态切换；
3.  
   DynamicDataSourceContextHolder：动态切换数据源；
4.  
   DynamicDataSourceRegister：动态数据源注册；
5.  
   TargetDataSource：在方法上使用，用于指定使用哪个数据源。

1.  
   package com.example.demo.datasource;
2.  
   import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
3.  
    
4.  
   /**
5.  
   * 动态数据源
6.  
   */
7.  
   public class DynamicDataSource extends AbstractRoutingDataSource {
8.  
   @Override
9.  
   protected Object determineCurrentLookupKey() {
10.  
    return DynamicDataSourceContextHolder.getDataSourceType();
11.  
    }
12.  
    }

1.  
   package com.example.demo.datasource;
2.  
    
3.  
   import org.aspectj.lang.JoinPoint;
4.  
   import org.aspectj.lang.annotation.After;
5.  
   import org.aspectj.lang.annotation.Aspect;
6.  
   import org.aspectj.lang.annotation.Before;
7.  
   import org.slf4j.Logger;
8.  
   import org.slf4j.LoggerFactory;
9.  
   import org.springframework.core.annotation.Order;
10.  
    import org.springframework.stereotype.Component;
11.  
     
12.  
    /**
13.  
    * 切换数据源Advice
14.  
    */
15.  
    @Aspect
16.  
    @Order(-1)// 保证该AOP在@Transactional之前执行
17.  
    @Component
18.  
    public class DynamicDataSourceAspect {
19.  
    private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceAspect.class);
20.  
     
21.  
    @Before("@annotation(ds)")
22.  
    public void changeDataSource(JoinPoint point, TargetDataSource ds) throws Throwable {
23.  
    String dsId = ds.name();
24.  
    if (!DynamicDataSourceContextHolder.containsDataSource(dsId)) {
25.  
    logger.error("数据源[{}]不存在，使用默认数据源 > {}", ds.name(), point.getSignature());
26.  
    }else {
27.  
    logger.debug("Use DataSource : {} > {}", dsId, point.getSignature());
28.  
    DynamicDataSourceContextHolder.setDataSourceType(dsId);
29.  
    }
30.  
     
31.  
    }
32.  
    @After("@annotation(ds)")
33.  
    public void restoreDataSource(JoinPoint point, TargetDataSource ds) {
34.  
    logger.debug("Revert DataSource : {} > {}", ds.name(), point.getSignature());
35.  
    DynamicDataSourceContextHolder.clearDataSourceType();
36.  
    }
37.  
    }

1.  
   package com.example.demo.datasource;
2.  
    
3.  
   import java.util.ArrayList;
4.  
   import java.util.List;
5.  
    
6.  
   public class DynamicDataSourceContextHolder {
7.  
   private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();
8.  
   public static List<String> dataSourceIds = new ArrayList<>();
9.  
    
10.  
    public static void setDataSourceType(String dataSourceType) {
11.  
    contextHolder.set(dataSourceType);
12.  
    }
13.  
     
14.  
    public static String getDataSourceType() {
15.  
    return contextHolder.get();
16.  
    }
17.  
     
18.  
    public static void clearDataSourceType() {
19.  
    contextHolder.remove();
20.  
    }
21.  
     
22.  
    /**
23.  
    * 判断指定DataSrouce当前是否存在
24.  
    */
25.  
    public static boolean containsDataSource(String dataSourceId){
26.  
    return dataSourceIds.contains(dataSourceId);
27.  
    }
28.  
    }

1.  
   package com.example.demo.datasource;
2.  
    
3.  
   import org.slf4j.Logger;
4.  
   import org.slf4j.LoggerFactory;
5.  
   import org.springframework.beans.MutablePropertyValues;
6.  
   import org.springframework.beans.PropertyValues;
7.  
   import org.springframework.beans.factory.annotation.Value;
8.  
   import org.springframework.beans.factory.support.BeanDefinitionRegistry;
9.  
   import org.springframework.beans.factory.support.GenericBeanDefinition;
10.  
    import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
11.  
    import org.springframework.boot.bind.RelaxedDataBinder;
12.  
    import org.springframework.boot.bind.RelaxedPropertyResolver;
13.  
    import org.springframework.context.EnvironmentAware;
14.  
    import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
15.  
    import org.springframework.core.convert.ConversionService;
16.  
    import org.springframework.core.convert.support.DefaultConversionService;
17.  
    import org.springframework.core.env.Environment;
18.  
    import org.springframework.core.type.AnnotationMetadata;
19.  
     
20.  
    import javax.sql.DataSource;
21.  
    import java.util.HashMap;
22.  
    import java.util.Map;
23.  
     
24.  
    /**
25.  
    * 动态数据源注册
26.  
    * 启动动态数据源请在启动类中 添加 @Import(DynamicDataSourceRegister.class)
27.  
    */
28.  
    public class DynamicDataSourceRegister
29.  
    implements ImportBeanDefinitionRegistrar, EnvironmentAware {
30.  
     
31.  
    private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceRegister.class);
32.  
    private ConversionService conversionService = new DefaultConversionService();
33.  
    private PropertyValues dataSourcePropertyValues;
34.  
     
35.  
    // 如配置文件中未指定数据源类型，使用该默认值
36.  
    private static final Object DATASOURCE_TYPE_DEFAULT = "com.alibaba.druid.pool.DruidDataSource";
37.  
     
38.  
    // 数据源
39.  
    private DataSource defaultDataSource;
40.  
    private Map<String, DataSource> customDataSources = new HashMap<>();
41.  
     
42.  
    private static String DB_NAME = "names";
43.  
    private static String DB_DEFAULT_VALUE = "custom.datasource"; //配置文件中前缀
44.  
    @Value("${bi.datasource.defaultname}")
45.  
    private String defaultDbname;
46.  
     
47.  
    //加载多数据源配置
48.  
    @Override
49.  
    public void setEnvironment(Environment env) {
50.  
    initDefaultDataSource(env);
51.  
    initCustomDataSources(env);
52.  
    }
53.  
     
54.  
    //初始化主数据源
55.  
    private void initDefaultDataSource(Environment env) {
56.  
    // 读取主数据源
57.  
    RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(env, DB_DEFAULT_VALUE+".");
58.  
    Map<String, Object> dsMap = new HashMap<>();
59.  
    dsMap.put("type", propertyResolver.getProperty("type"));
60.  
    dsMap.put("driver-class-name", propertyResolver.getProperty("driver-class-name"));
61.  
    dsMap.put("url", propertyResolver.getProperty("url"));
62.  
    dsMap.put("username", propertyResolver.getProperty("username"));
63.  
    dsMap.put("password", propertyResolver.getProperty("password"));
64.  
     
65.  
    defaultDataSource = buildDataSource(dsMap);
66.  
    customDataSources.put(defaultDbname,defaultDataSource);//默认数据源放到动态数据源里
67.  
    dataBinder(defaultDataSource, env);
68.  
    }
69.  
     
70.  
     
71.  
    //为DataSource绑定更多数据
72.  
    private void dataBinder(DataSource dataSource, Environment env) {
73.  
    RelaxedDataBinder dataBinder = new RelaxedDataBinder(dataSource);
74.  
    //dataBinder.setValidator(new LocalValidatorFactory().run(this.applicationContext));
75.  
    dataBinder.setConversionService(conversionService);
76.  
    dataBinder.setIgnoreNestedProperties(false);//false
77.  
    dataBinder.setIgnoreInvalidFields(false);//false
78.  
    dataBinder.setIgnoreUnknownFields(true);//true
79.  
    if (dataSourcePropertyValues == null) {
80.  
    Map<String, Object> rpr = new RelaxedPropertyResolver(env, DB_DEFAULT_VALUE).getSubProperties(".");
81.  
    Map<String, Object> values = new HashMap<String, Object>(rpr);
82.  
    // 排除已经设置的属性
83.  
    values.remove("type");
84.  
    values.remove("driver-class-name");
85.  
    values.remove("url");
86.  
    values.remove("username");
87.  
    values.remove("password");
88.  
    dataSourcePropertyValues = new MutablePropertyValues(values);
89.  
    }
90.  
    dataBinder.bind(dataSourcePropertyValues);
91.  
    }
92.  
     
93.  
    //初始化更多数据源
94.  
    private void initCustomDataSources(Environment env) {
95.  
    // 读取配置文件获取更多数据源，也可以通过defaultDataSource读取数据库获取更多数据源
96.  
    RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(env,DB_DEFAULT_VALUE+".");
97.  
    String dsPrefixs = propertyResolver.getProperty(DB_NAME);
98.  
    for (String dsPrefix : dsPrefixs.split(",")) {// 多个数据源
99.  
    Map<String, Object> dsMap = propertyResolver.getSubProperties(dsPrefix + ".");
100.  
     DataSource ds = buildDataSource(dsMap);
101.  
     customDataSources.put(dsPrefix, ds);
102.  
     dataBinder(ds, env);
103.  
     }
104.  
     }
105.  
      
106.  
     @Override
107.  
     public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
108.  
     Map<Object, Object> targetDataSources = new HashMap<Object, Object>();
109.  
     // 将主数据源添加到更多数据源中
110.  
     targetDataSources.put("dataSource", defaultDataSource);
111.  
     DynamicDataSourceContextHolder.dataSourceIds.add("dataSource");
112.  
     // 添加更多数据源
113.  
     targetDataSources.putAll(customDataSources);
114.  
     for (String key : customDataSources.keySet()) {
115.  
     DynamicDataSourceContextHolder.dataSourceIds.add(key);
116.  
     }
117.  
      
118.  
     // 创建DynamicDataSource
119.  
     GenericBeanDefinition beanDefinition = new GenericBeanDefinition();
120.  
     beanDefinition.setBeanClass(DynamicDataSource.class);
121.  
     beanDefinition.setSynthetic(true);
122.  
     MutablePropertyValues mpv = beanDefinition.getPropertyValues();
123.  
     mpv.addPropertyValue("defaultTargetDataSource", defaultDataSource);
124.  
     mpv.addPropertyValue("targetDataSources", targetDataSources);
125.  
     registry.registerBeanDefinition("dataSource", beanDefinition);
126.  
      
127.  
     logger.info("Dynamic DataSource Registry");
128.  
     }
129.  
      
130.  
     //创建DataSource
131.  
     @SuppressWarnings("unchecked")
132.  
     public DataSource buildDataSource(Map<String, Object> dsMap) {
133.  
     try {
134.  
     Object type = dsMap.get("type");
135.  
     if (type == null)
136.  
     type = DATASOURCE_TYPE_DEFAULT;// 默认DataSource
137.  
      
138.  
     Class<? extends DataSource> dataSourceType;
139.  
     dataSourceType = (Class<? extends DataSource>) Class.forName((String) type);
140.  
      
141.  
     String driverClassName = dsMap.get("driver-class-name").toString();
142.  
     String url = dsMap.get("url").toString();
143.  
     String username = dsMap.get("username").toString();
144.  
     String password = dsMap.get("password").toString();
145.  
      
146.  
     DataSourceBuilder factory = DataSourceBuilder.create().driverClassName(driverClassName).url(url)
147.  
     .username(username).password(password).type(dataSourceType);
148.  
     return factory.build();
149.  
     } catch (ClassNotFoundException e) {
150.  
     e.printStackTrace();
151.  
     }
152.  
     return null;
153.  
     }
154.  
     }

1.  
   package com.example.demo.datasource;
2.  
    
3.  
   import java.lang.annotation.Documented;
4.  
   import java.lang.annotation.ElementType;
5.  
   import java.lang.annotation.Retention;
6.  
   import java.lang.annotation.RetentionPolicy;
7.  
   import java.lang.annotation.Target;
8.  
    
9.  
   // 在方法上使用，用于指定使用哪个数据源
10.  
    @Target({ ElementType.METHOD, ElementType.TYPE })
11.  
    @Retention(RetentionPolicy.RUNTIME)
12.  
    @Documented
13.  
    public @interface TargetDataSource {
14.  
    String name();
15.  
    }

3.3 启动类添加注解

添加注解 @Import ：注册动态多数据源；

添加 @MapperScan ：将项目中对应的mapper类的路径加进来

1.  
   package com.example.demo;
2.  
    
3.  
   import com.example.demo.datasource.DynamicDataSourceRegister;
4.  
   import org.mybatis.spring.annotation.MapperScan;
5.  
   import org.springframework.boot.SpringApplication;
6.  
   import org.springframework.boot.autoconfigure.SpringBootApplication;
7.  
   import org.springframework.context.annotation.Import;
8.  
    
9.  
   @SpringBootApplication
10.  
    @Import({DynamicDataSourceRegister.class}) // 注册动态多数据源
11.  
    @MapperScan("com.example.demo.dao")//将项目中对应的mapper类的路径加进来就可以了
12.  
    public class DynamicDataSourceApplication {
13.  
    public static void main(String[] args) {
14.  
    SpringApplication.run(DynamicDataSourceApplication.class, args);
15.  
    }
16.  
    }

四、使用方法

4.1 Controller

1.  
   package com.example.demo.controller;
2.  
    
3.  
   import com.example.demo.model.Student;
4.  
   import com.example.demo.model.Teacher;
5.  
   import com.example.demo.model.User;
6.  
   import com.example.demo.service.DynamicDataSourceService;
7.  
   import org.springframework.beans.factory.annotation.Autowired;
8.  
   import org.springframework.web.bind.annotation.PathVariable;
9.  
   import org.springframework.web.bind.annotation.RequestMapping;
10.  
    import org.springframework.web.bind.annotation.RestController;
11.  
     
12.  
    import java.util.List;
13.  
     
14.  
    @RestController
15.  
    @RequestMapping(value = "/dds")
16.  
    public class DynamicDataSourceController {
17.  
     
18.  
    @Autowired
19.  
    private DynamicDataSourceService service;
20.  
     
21.  
    @RequestMapping(value = "/user/{id}")
22.  
    public User getAllUserData(@PathVariable Integer id){
23.  
    return service.getUserData(id);
24.  
    }
25.  
     
26.  
    @RequestMapping(value = "/teacher/{id}")
27.  
    public Teacher getAllTeacherData(@PathVariable Integer id) {
28.  
    return service.getTeacherData(id);
29.  
    }
30.  
     
31.  
    @RequestMapping(value = "/student/{id}")
32.  
    public Student getAllStudentData(@PathVariable Integer id) {
33.  
    return service.getStudentData(id);
34.  
    }
35.  
    }

4.2 Service

注解@TargetDataSource 不能直接在接口类Mapper上使用，所以在Service上使用。

1.  
   package com.example.demo.service;
2.  
    
3.  
   import com.example.demo.dao.StudentMapper;
4.  
   import com.example.demo.dao.TeacherMapper;
5.  
   import com.example.demo.dao.UserMapper;
6.  
   import com.example.demo.datasource.TargetDataSource;
7.  
   import com.example.demo.model.Student;
8.  
   import com.example.demo.model.Teacher;
9.  
   import com.example.demo.model.User;
10.  
    import org.springframework.beans.factory.annotation.Autowired;
11.  
    import org.springframework.stereotype.Service;
12.  
    import java.util.List;
13.  
     
14.  
    @Service
15.  
    public class DynamicDataSourceService {
16.  
     
17.  
    @Autowired
18.  
    private UserMapper userMapper;
19.  
    @Autowired
20.  
    private TeacherMapper teacherMapper;
21.  
    @Autowired
22.  
    private StudentMapper studentMapper;
23.  
     
24.  
     
25.  
    //不指定数据源使用默认数据源
26.  
    public User getUserData(Integer id) {
27.  
    return userMapper.selectByPrimaryKey(id);
28.  
    }
29.  
     
30.  
    //指定数据源-ds1
31.  
    @TargetDataSource(name="ds1")
32.  
    public Teacher getTeacherData(Integer id) {
33.  
    return teacherMapper.selectByPrimaryKey(id);
34.  
    }
35.  
     
36.  
    //指定数据源-ds2
37.  
    @TargetDataSource(name="ds2")
38.  
    public Student getStudentData(Integer id) {
39.  
    return studentMapper.selectByPrimaryKey(id);
40.  
    }
41.  
    }

五、测试

• localhost:8080//dds/user/1

• localhost:8080//dds/teacher/1

• localhost:8080//dds/student/1

 

六、Springboot2.0动态多数据源切换

Springboot 1.x 到 Springboot 2.0配置变化有一点变化。主要是 RelaxedPropertyResolver不再可以Environment自动处理。

主要 是 DynamicDataSourceRegister 中有部分方法不一样。其他方法都不需要修改。

1.  
   package com.example.demo.datasource;
2.  
    
3.  
   import org.slf4j.Logger;
4.  
   import org.slf4j.LoggerFactory;
5.  
   import org.springframework.beans.MutablePropertyValues;
6.  
   import org.springframework.beans.factory.annotation.Value;
7.  
   import org.springframework.beans.factory.support.BeanDefinitionRegistry;
8.  
   import org.springframework.beans.factory.support.GenericBeanDefinition;
9.  
   import org.springframework.boot.jdbc.DataSourceBuilder;
10.  
    import org.springframework.context.EnvironmentAware;
11.  
    import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
12.  
    import org.springframework.core.env.Environment;
13.  
    import org.springframework.core.type.AnnotationMetadata;
14.  
     
15.  
    import javax.sql.DataSource;
16.  
    import java.util.HashMap;
17.  
    import java.util.Map;
18.  
     
19.  
    /**
20.  
    * 动态数据源注册<br/>
21.  
    * 启动动态数据源请在启动类中 添加 @Import(DynamicDataSourceRegister.class)
22.  
    */
23.  
    public class DynamicDataSourceRegister
24.  
    implements ImportBeanDefinitionRegistrar, EnvironmentAware {
25.  
     
26.  
    private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceRegister.class);
27.  
     
28.  
    // 如配置文件中未指定数据源类型，使用该默认值
29.  
    private static final Object DATASOURCE_TYPE_DEFAULT = "com.alibaba.druid.pool.DruidDataSource";
30.  
     
31.  
    // 数据源
32.  
    private DataSource defaultDataSource;
33.  
    private Map<String, DataSource> customDataSources = new HashMap<>();
34.  
     
35.  
    private static String DB_NAME = "names";
36.  
    private static String DB_DEFAULT_VALUE = "custom.datasource";
37.  
    @Value("${bi.datasource.defaultname}")
38.  
    private String defaultDbname;
39.  
     
40.  
    /**
41.  
    * 加载多数据源配置
42.  
    */
43.  
    @Override
44.  
    public void setEnvironment(Environment env) {
45.  
    initDefaultDataSource(env);
46.  
    initCustomDataSources(env);
47.  
    }
48.  
     
49.  
    /**
50.  
    * 1.5.8 初始化主数据源
51.  
    */
52.  
    // private void initDefaultDataSource(Environment env) {
53.  
    // // 读取主数据源
54.  
    // RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(env, DB_DEFAULT_VALUE+".");
55.  
    // Map<String, Object> dsMap = new HashMap<>();
56.  
    // dsMap.put("type", propertyResolver.getProperty("type"));
57.  
    // dsMap.put("driver-class-name", propertyResolver.getProperty("driver-class-name"));
58.  
    // dsMap.put("url", propertyResolver.getProperty("url"));
59.  
    // dsMap.put("username", propertyResolver.getProperty("username"));
60.  
    // dsMap.put("password", propertyResolver.getProperty("password"));
61.  
    //
62.  
    // defaultDataSource = buildDataSource(dsMap);
63.  
    // customDataSources.put(defaultDbname,defaultDataSource);//默认数据源放到动态数据源里
64.  
    // dataBinder(defaultDataSource, env);
65.  
    // }
66.  
    /**
67.  
    * 2.0.4 初始化主数据源
68.  
    */
69.  
    private void initDefaultDataSource(Environment env) {
70.  
    // 读取主数据源
71.  
    Map<String, Object> dsMap = new HashMap<>();
72.  
    dsMap.put("type", env.getProperty(DB_DEFAULT_VALUE + "." + "type"));
73.  
    dsMap.put("driver-class-name", env.getProperty(DB_DEFAULT_VALUE + "." + "driver-class-name"));
74.  
    dsMap.put("url", env.getProperty(DB_DEFAULT_VALUE + "." + "url"));
75.  
    dsMap.put("username", env.getProperty(DB_DEFAULT_VALUE + "." + "username"));
76.  
    dsMap.put("password", env.getProperty(DB_DEFAULT_VALUE + "." + "password"));
77.  
    defaultDataSource = buildDataSource(dsMap);
78.  
    // customDataSources.put(defaultDbname,defaultDataSource);//默认数据源放到动态数据源里
79.  
    // dataBinder(defaultDataSource, env);
80.  
    }
81.  
     
82.  
     
83.  
    /**
84.  
    * 为DataSource绑定更多数据
85.  
    *
86.  
    */
87.  
    // private void dataBinder(DataSource dataSource, Environment env) {
88.  
    // RelaxedDataBinder dataBinder = new RelaxedDataBinder(dataSource);
89.  
    // //dataBinder.setValidator(new LocalValidatorFactory().run(this.applicationContext));
90.  
    // dataBinder.setConversionService(conversionService);
91.  
    // dataBinder.setIgnoreNestedProperties(false);//false
92.  
    // dataBinder.setIgnoreInvalidFields(false);//false
93.  
    // dataBinder.setIgnoreUnknownFields(true);//true
94.  
    // if (dataSourcePropertyValues == null) {
95.  
    // Map<String, Object> rpr = new RelaxedPropertyResolver(env, DB_DEFAULT_VALUE).getSubProperties(".");
96.  
    // Map<String, Object> values = new HashMap<String, Object>(rpr);
97.  
    // // 排除已经设置的属性
98.  
    // values.remove("type");
99.  
    // values.remove("driver-class-name");
100.  
     // values.remove("url");
101.  
     // values.remove("username");
102.  
     // values.remove("password");
103.  
     // dataSourcePropertyValues = new MutablePropertyValues(values);
104.  
     // }
105.  
     // dataBinder.bind(dataSourcePropertyValues);
106.  
     // }
107.  
      
108.  
     // 初始化更多数据源
109.  
     private void initCustomDataSources(Environment env) {
110.  
     // 读取配置文件获取更多数据源，也可以通过defaultDataSource读取数据库获取更多数据源
111.  
     // RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(env,DB_DEFAULT_VALUE+".");
112.  
     String dsPrefixs = env.getProperty(DB_DEFAULT_VALUE + "." + DB_NAME);
113.  
     for (String dsPrefix : dsPrefixs.split(",")) {// 多个数据源
114.  
     Map<String, Object> dsMap = new HashMap<>();
115.  
      
116.  
     dsMap.put("type", env.getProperty(DB_DEFAULT_VALUE + "." + dsPrefix + ".type"));
117.  
     dsMap.put("driver-class-name", env.getProperty(DB_DEFAULT_VALUE + "." + dsPrefix + ".driver-class-name"));
118.  
     dsMap.put("url", env.getProperty(DB_DEFAULT_VALUE + "." + dsPrefix + ".url"));
119.  
     dsMap.put("username", env.getProperty(DB_DEFAULT_VALUE + "." + dsPrefix + ".username"));
120.  
     dsMap.put("password", env.getProperty(DB_DEFAULT_VALUE + "." + dsPrefix + ".password"));
121.  
      
122.  
      
123.  
     DataSource ds = buildDataSource(dsMap);
124.  
     customDataSources.put(dsPrefix, ds);
125.  
     }
126.  
     }
127.  
      
128.  
      
129.  
      
130.  
     @Override
131.  
     public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
132.  
     Map<Object, Object> targetDataSources = new HashMap<Object, Object>();
133.  
     // 将主数据源添加到更多数据源中
134.  
     targetDataSources.put("dataSource", defaultDataSource);
135.  
     DynamicDataSourceContextHolder.dataSourceIds.add("dataSource");
136.  
     // 添加更多数据源
137.  
     targetDataSources.putAll(customDataSources);
138.  
     for (String key : customDataSources.keySet()) {
139.  
     DynamicDataSourceContextHolder.dataSourceIds.add(key);
140.  
     }
141.  
      
142.  
     // 创建DynamicDataSource
143.  
     GenericBeanDefinition beanDefinition = new GenericBeanDefinition();
144.  
     beanDefinition.setBeanClass(DynamicDataSource.class);
145.  
     beanDefinition.setSynthetic(true);
146.  
     MutablePropertyValues mpv = beanDefinition.getPropertyValues();
147.  
     mpv.addPropertyValue("defaultTargetDataSource", defaultDataSource);
148.  
     mpv.addPropertyValue("targetDataSources", targetDataSources);
149.  
     registry.registerBeanDefinition("dataSource", beanDefinition);
150.  
      
151.  
     logger.info("Dynamic DataSource Registry");
152.  
     }
153.  
      
154.  
     // 创建DataSource
155.  
     @SuppressWarnings("unchecked")
156.  
     public DataSource buildDataSource(Map<String, Object> dsMap) {
157.  
     try {
158.  
     Object type = dsMap.get("type");
159.  
     if (type == null)
160.  
     type = DATASOURCE_TYPE_DEFAULT;// 默认DataSource
161.  
      
162.  
     Class<? extends DataSource> dataSourceType;
163.  
     dataSourceType = (Class<? extends DataSource>) Class.forName((String) type);
164.  
      
165.  
     String driverClassName = dsMap.get("driver-class-name").toString();
166.  
     String url = dsMap.get("url").toString();
167.  
     String username = dsMap.get("username").toString();
168.  
     String password = dsMap.get("password").toString();
169.  
      
170.  
     DataSourceBuilder factory = DataSourceBuilder.create().driverClassName(driverClassName).url(url)
171.  
     .username(username).password(password).type(dataSourceType);
172.  
     return factory.build();
173.  
     } catch (ClassNotFoundException e) {
174.  
     e.printStackTrace();
175.  
     }
176.  
     return null;
177.  
     }
178.  
     }

 

参考文献

Spring Boot 动态数据源（多数据源自动切换）

https://blog.csdn.net/cllaure/article/details/81509303?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.channel_param&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.channel_param