Spring Boot+Mybatis+Druid+PageHelper实现多数据源并分页的方法

<dependency>
 <groupId>com.alibaba</groupId>
 <artifactId>druid</artifactId>
 <version>1.1.8</version>
 </dependency>

## 默认的数据源

master.datasource.url=jdbc:mysql://localhost:3306/springBoot?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true
master.datasource.username=root
master.datasource.password=123456
master.datasource.driverClassName=com.mysql.jdbc.Driver


## 另一个的数据源
cluster.datasource.url=jdbc:mysql://localhost:3306/springBoot_test?useUnicode=true&characterEncoding=utf8
cluster.datasource.username=root
cluster.datasource.password=123456
cluster.datasource.driverClassName=com.mysql.jdbc.Driver

# 连接池的配置信息 
# 初始化大小，最小，最大 
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.initialSize=5 
spring.datasource.minIdle=5 
spring.datasource.maxActive=20 
# 配置获取连接等待超时的时间 
spring.datasource.maxWait=60000 
# 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 
spring.datasource.timeBetweenEvictionRunsMillis=60000 
# 配置一个连接在池中最小生存的时间，单位是毫秒 
spring.datasource.minEvictableIdleTimeMillis=300000 
spring.datasource.validationQuery=SELECT 1 FROM DUAL 
spring.datasource.testWhileIdle=true 
spring.datasource.testOnBorrow=false 
spring.datasource.testOnReturn=false 
# 打开PSCache，并且指定每个连接上PSCache的大小 
spring.datasource.poolPreparedStatements=true 
spring.datasource.maxPoolPreparedStatementPerConnectionSize=20 
# 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙 
spring.datasource.filters=stat,wall,log4j 
# 通过connectProperties属性来打开mergeSql功能；慢SQL记录 
spring.datasource.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000 

@Configuration
@MapperScan(basePackages = MasterDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MasterDataSourceConfig {

 static final String PACKAGE = "com.pancm.dao.master";
 static final String MAPPER_LOCATION = "classpath:mapper/master/*.xml";

 @Value("${master.datasource.url}") 
 private String url; 
 
 @Value("${master.datasource.username}") 
 private String username; 
 
 @Value("${master.datasource.password}") 
 private String password; 
 
 @Value("${master.datasource.driverClassName}") 
 private String driverClassName; 
 
 
 
 
 @Value("${spring.datasource.initialSize}") 
 private int initialSize; 
 
 @Value("${spring.datasource.minIdle}") 
 private int minIdle; 
 
 @Value("${spring.datasource.maxActive}") 
 private int maxActive; 
 
 @Value("${spring.datasource.maxWait}") 
 private int maxWait; 
 
 @Value("${spring.datasource.timeBetweenEvictionRunsMillis}") 
 private int timeBetweenEvictionRunsMillis; 
 
 @Value("${spring.datasource.minEvictableIdleTimeMillis}") 
 private int minEvictableIdleTimeMillis; 
 
 @Value("${spring.datasource.validationQuery}") 
 private String validationQuery; 
 
 @Value("${spring.datasource.testWhileIdle}") 
 private boolean testWhileIdle; 
 
 @Value("${spring.datasource.testOnBorrow}") 
 private boolean testOnBorrow; 
 
 @Value("${spring.datasource.testOnReturn}") 
 private boolean testOnReturn; 
 
 @Value("${spring.datasource.poolPreparedStatements}") 
 private boolean poolPreparedStatements; 
 
 @Value("${spring.datasource.maxPoolPreparedStatementPerConnectionSize}") 
 private int maxPoolPreparedStatementPerConnectionSize; 
 
 @Value("${spring.datasource.filters}") 
 private String filters; 
 
 @Value("{spring.datasource.connectionProperties}") 
 private String connectionProperties; 
 
 
 @Bean(name = "masterDataSource")
 @Primary 
 public DataSource masterDataSource() {
 DruidDataSource dataSource = new DruidDataSource();
 dataSource.setUrl(url); 
 dataSource.setUsername(username); 
 dataSource.setPassword(password); 
 dataSource.setDriverClassName(driverClassName); 
 
 //具体配置 
 dataSource.setInitialSize(initialSize); 
 dataSource.setMinIdle(minIdle); 
 dataSource.setMaxActive(maxActive); 
 dataSource.setMaxWait(maxWait); 
 dataSource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis); 
 dataSource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis); 
 dataSource.setValidationQuery(validationQuery); 
 dataSource.setTestWhileIdle(testWhileIdle); 
 dataSource.setTestOnBorrow(testOnBorrow); 
 dataSource.setTestOnReturn(testOnReturn); 
 dataSource.setPoolPreparedStatements(poolPreparedStatements); 
 dataSource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize); 
 try { 
 dataSource.setFilters(filters); 
 } catch (SQLException e) { 
 e.printStackTrace();
 } 
 dataSource.setConnectionProperties(connectionProperties); 
 return dataSource;
 }

 @Bean(name = "masterTransactionManager")
 @Primary
 public DataSourceTransactionManager masterTransactionManager() {
 return new DataSourceTransactionManager(masterDataSource());
 }

 @Bean(name = "masterSqlSessionFactory")
 @Primary
 public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource)
 throws Exception {
 final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
 sessionFactory.setDataSource(masterDataSource);
 sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
 .getResources(MasterDataSourceConfig.MAPPER_LOCATION));
 return sessionFactory.getObject();
 }
}

@Configuration
public class DruidConfiguration {

 @Bean
 public ServletRegistrationBean druidStatViewServle() {
 //注册服务
 ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(
 new StatViewServlet(), "/druid/*");
 // 白名单(为空表示,所有的都可以访问,多个IP的时候用逗号隔开)
 servletRegistrationBean.addInitParameter("allow", "127.0.0.1");
 // IP黑名单 (存在共同时，deny优先于allow) 
 servletRegistrationBean.addInitParameter("deny", "127.0.0.2");
 // 设置登录的用户名和密码
 servletRegistrationBean.addInitParameter("loginUsername", "pancm");
 servletRegistrationBean.addInitParameter("loginPassword", "123456");
 // 是否能够重置数据.
 servletRegistrationBean.addInitParameter("resetEnable", "false");
 return servletRegistrationBean;
 }

 @Bean
 public FilterRegistrationBean druidStatFilter() {
 FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(
 new WebStatFilter());
 // 添加过滤规则
 filterRegistrationBean.addUrlPatterns("/*");
 // 添加不需要忽略的格式信息
 filterRegistrationBean.addInitParameter("exclusions",
 "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");
 System.out.println("druid初始化成功!");
 return filterRegistrationBean;
 }
}

-- springBoot库的脚本

CREATE TABLE `t_user` (
 `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '自增id',
 `name` varchar(10) DEFAULT NULL COMMENT '姓名',
 `age` int(2) DEFAULT NULL COMMENT '年龄',
 PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=15 DEFAULT CHARSET=utf8

-- springBoot_test库的脚本

CREATE TABLE `t_student` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `name` varchar(16) DEFAULT NULL,
 `age` int(11) DEFAULT NULL,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8

@Configuration
@MapperScan(basePackages = ClusterDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "clusterSqlSessionFactory")
public class ClusterDataSourceConfig {

 static final String PACKAGE = "com.pancm.dao.cluster";
 static final String MAPPER_LOCATION = "classpath:mapper/cluster/*.xml";

 @Value("${cluster.datasource.url}")
 private String url;

 @Value("${cluster.datasource.username}")
 private String username;

 @Value("${cluster.datasource.password}")
 private String password;

 @Value("${cluster.datasource.driverClassName}")
 private String driverClass;

 // 和MasterDataSourceConfig一样，这里略

 @Bean(name = "clusterDataSource")
 public DataSource clusterDataSource() {
 DruidDataSource dataSource = new DruidDataSource();
 dataSource.setUrl(url); 
 dataSource.setUsername(username); 
 dataSource.setPassword(password); 
 dataSource.setDriverClassName(driverClass); 
 
 // 和MasterDataSourceConfig一样，这里略 ...
 return dataSource;
 }

 @Bean(name = "clusterTransactionManager")
 public DataSourceTransactionManager clusterTransactionManager() {
 return new DataSourceTransactionManager(clusterDataSource());
 }

 @Bean(name = "clusterSqlSessionFactory")
 public SqlSessionFactory clusterSqlSessionFactory(@Qualifier("clusterDataSource") DataSource clusterDataSource)
 throws Exception {
 final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
 sessionFactory.setDataSource(clusterDataSource);
 sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(ClusterDataSourceConfig.MAPPER_LOCATION));
 return sessionFactory.getObject();
 }
}

POST http://localhost:8084/api/user
{"name":"张三","age":25}
{"name":"李四","age":25}
{"name":"王五","age":25}

POST http://localhost:8084/api/student
{"name":"学生A","age":16}
{"name":"学生B","age":17}
{"name":"学生C","age":18}

GET http://localhost:8084/api/user?name=李四

{
 "id": 2,
 "name": "李四",
 "age": 25
}

 GET http://localhost:8084/api/student?name=学生C

{
 "id": 1,
 "name": "学生C",
 "age": 16
}

 <dependency>
  <groupId>com.github.pagehelper</groupId>
  <artifactId>pagehelper-spring-boot-starter</artifactId>
  <version>1.2.3</version>
 </dependency>

 pagehelper:
 helperDialect: mysql
 offsetAsPageNum: true
 rowBoundsWithCount: true
 reasonable: false

 <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
 <property name="dataSource" ref="dataSource" />
 <!-- 扫描mapping.xml文件 -->
 <property name="mapperLocations" value="classpath:mapper/*.xml"></property>
 <!-- 配置分页插件 -->
 <property name="plugins">
 <array>
  <bean class="com.github.pagehelper.PageHelper">
  <property name="properties">
  <value>
  helperDialect=mysql
  offsetAsPageNum=true
  rowBoundsWithCount=true
  reasonable=false
  </value>
  </property>
  </bean>
 </array>
 </property>
 </bean>

 @Bean
 public PageHelper pageHelper(){
 PageHelper pageHelper = new PageHelper();
 Properties properties = new Properties();
 //数据库
 properties.setProperty("helperDialect", "mysql");
 //是否将参数offset作为PageNum使用
 properties.setProperty("offsetAsPageNum", "true");
 //是否进行count查询
 properties.setProperty("rowBoundsWithCount", "true");
 //是否分页合理化
 properties.setProperty("reasonable", "false");
 pageHelper.setProperties(properties);
 }

 @Bean(name = "masterSqlSessionFactory")
 @Primary
 public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource)
  throws Exception {
 final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
 sessionFactory.setDataSource(masterDataSource);
 sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
  .getResources(MasterDataSourceConfig.MAPPER_LOCATION));
 //分页插件
 Interceptor interceptor = new PageInterceptor();
 Properties properties = new Properties();
 //数据库
 properties.setProperty("helperDialect", "mysql");
 //是否将参数offset作为PageNum使用
 properties.setProperty("offsetAsPageNum", "true");
 //是否进行count查询
 properties.setProperty("rowBoundsWithCount", "true");
 //是否分页合理化
 properties.setProperty("reasonable", "false");
 interceptor.setProperties(properties);
 sessionFactory.setPlugins(new Interceptor[] {interceptor});
 
 return sessionFactory.getObject();
 }

public List<T> findByListEntity(T entity) {
 List<T> list = null;
 try {
  Page<?> page =PageHelper.startPage(1,2); 
  System.out.println(getClassName(entity)+"设置第一页两条数据!");
  list = getMapper().findByListEntity(entity);
  System.out.println("总共有:"+page.getTotal()+"条数据,实际返回:"+list.size()+"两条数据!");
 } catch (Exception e) {
  logger.error("查询"+getClassName(entity)+"失败!原因是:",e);
 }
 return list;
 }

GET http://localhost:8084/api/user

[
 {
 "id": 1,
 "name": "张三",
 "age": 25
 },
 {
 "id": 2,
 "name": "李四",
 "age": 25
 }
]

GET http://localhost:8084/api/student

[
 {
 "id": 1,
 "name": "学生A",
 "age": 16
 },
 {
 "id": 2,
 "name": "学生B",
 "age": 17
 }
]