此文做记录交流,如有不当,还望指正。
事务(Transaction),一般是指要做的或所做的事情。在计算机中是指访问并可能更新数据库中各种数据项
的一个程序执行单元(unit)。事务(Transaction)是访问并可能更新数据库中各种数据项
的一个程序执行单元(unit)。事务通常由高级数据库操纵语言或编程语言(如SQL,C++或Java)书写的用户程序的执行所引起,并用形如begin transaction和end transaction语句(或函数调用)来界定。事务由事务开始(begin transaction)和事务结束(end transaction)之间执行的全体操作组成。
事务应该具有4个属性:原子性、一致性、隔离性、持久性。这四个属性通常称为ACID特性。
原子性(atomicity)。一个事务是一个不可分割的工作单位,事务中包括的诸操作要么都做,要么都不做。
一致性(consistency)。事务必须是使数据库从一个一致性状态变到另一个一致性状态。一致性与原子性是密切相关的。
隔离性(isolation)。一个事务的执行不能被其他事务干扰。即一个事务内部的操作及使用的数据对并发的其他事务是隔离的,并发执行的各个事务之间不能互相干扰。
持久性(durability)。持久性也称永久性(permanence),指一个事务一旦提交,它对数据库中数据的改变就应该是永久性的。接下来的其他操作或故障不应该对其有任何影响。
本节我们测试spring boot 简单配置事务及读写分离的处理
首先按照上节我们创建一个spring boot 项目,mybaties做持久层的处理!
项目创建完成后结构如下:
spring boot 添加事务处理
我们在我们的service中新增一个insert方法
package com.demo.springboot_mybatis.service;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.demo.springboot_mybatis.mapper.OrganizationNameMapper;
import com.demo.springboot_mybatis.model.OrganizationName;
@Service
public class OrganizationNameService
extends AbstractBaseService<OrganizationNameMapper, OrganizationName> {
public int insertOrganizationName(){
OrganizationName org1 = new OrganizationName();
OrganizationName org2 = new OrganizationName();
OrganizationName org3 = new OrganizationName();
OrganizationName org4 = new OrganizationName();
org1.setId(101l);
org1.setOrganizationName("101");
org2.setId(102l);
org2.setOrganizationName("102");
org3.setId(103l);
org3.setOrganizationName("103");
org4.setId(104l);
org4.setOrganizationName("104");
this.mapper.insert(org1);
this.mapper.insert(org2);
this.mapper.insert(org3);
this.mapper.insert(org4);
throw new RuntimeException();
}
}
controller中调用
package com.demo.springboot_mybatis.web;
import javax.servlet.http.HttpServletRequest;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.demo.springboot_mybatis.service.OrganizationNameService;
@RestController
public class RestHelloController {
@Autowired
OrganizationNameService organizationNameService;
@RequestMapping("/insert")
public String insert(HttpServletRequest request) throws Exception{
organizationNameService.insertOrganizationName();
return "";
}
}
启动项目访问http://localhost:8080/insert
我们发现项目访问出错了,但是依然数据进库了!这是因为我们没有添加事务处理的结果!我们在我们的service中的insert方法上面加上@Transactional后,并更改我们插入的数据
@Transactional
public int insertOrganizationName(){
OrganizationName org1 = new OrganizationName();
OrganizationName org2 = new OrganizationName();
OrganizationName org3 = new OrganizationName();
OrganizationName org4 = new OrganizationName();
org1.setId(105l);
org1.setOrganizationName("105");
org2.setId(106l);
org2.setOrganizationName("106");
org3.setId(107l);
org3.setOrganizationName("107");
org4.setId(108l);
org4.setOrganizationName("108");
this.mapper.insert(org1);
this.mapper.insert(org2);
this.mapper.insert(org3);
this.mapper.insert(org4);
throw new RuntimeException();
}
重新启动我们的项目访问http://localhost:8080/insert
我们发现访问依然报错,但是数据是没有入库的
我们取消我们方法中的throw后
@Transactional
public int insertOrganizationName(){
OrganizationName org1 = new OrganizationName();
OrganizationName org2 = new OrganizationName();
OrganizationName org3 = new OrganizationName();
OrganizationName org4 = new OrganizationName();
org1.setId(105l);
org1.setOrganizationName("105");
org2.setId(106l);
org2.setOrganizationName("106");
org3.setId(107l);
org3.setOrganizationName("107");
org4.setId(108l);
org4.setOrganizationName("108");
this.mapper.insert(org1);
this.mapper.insert(org2);
this.mapper.insert(org3);
this.mapper.insert(org4);
return 1;
}
重新启动我们的项目访问http://localhost:8080/insert
没有报错,并且数据成功入库
读写分离的处理方式 service层事务控制
编写数据源类 MyDruidDataSource
package com.demo.springboot_mybatis.config;
import java.sql.SQLException;
import javax.sql.DataSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.alibaba.druid.pool.DruidDataSource;
@Configuration
public class MyDruidDataSource {
private Logger logger = LoggerFactory.getLogger(MyDruidDataSource.class);
@Value("${datasource.read.url}")
private String dbUrlRead;
@Value("${datasource.read.username}")
private String usernameRead;
@Value("${datasource.read.password}")
private String passwordRead;
@Value("${datasource.read.driverClassName}")
private String driverClassNameRead;
@Value("${datasource.read.initialSize}")
private int initialSizeRead;
@Value("${datasource.read.minIdle}")
private int minIdleRead;
@Value("${datasource.read.maxActive}")
private int maxActiveRead;
@Value("${datasource.read.maxWait}")
private int maxWaitRead;
@Value("${datasource.read.timeBetweenEvictionRunsMillis}")
private int timeBetweenEvictionRunsMillisRead;
@Value("${datasource.read.minEvictableIdleTimeMillis}")
private int minEvictableIdleTimeMillisRead;
@Value("${datasource.read.validationQuery}")
private String validationQueryRead;
@Value("${datasource.read.testWhileIdle}")
private boolean testWhileIdleRead;
@Value("${datasource.read.testOnBorrow}")
private boolean testOnBorrowRead;
@Value("${datasource.read.testOnReturn}")
private boolean testOnReturnRead;
@Value("${datasource.read.poolPreparedStatements}")
private boolean poolPreparedStatementsRead;
@Value("${datasource.read.filters}")
private String filtersRead;
@Value("${datasource.read.connectionProperties}")
private String connectionPropertiesRead;
@Value("${datasource.write.url}")
private String dbUrl;
@Value("${datasource.write.username}")
private String username;
@Value("${datasource.write.password}")
private String password;
@Value("${datasource.write.driverClassName}")
private String driverClassName;
@Value("${datasource.write.initialSize}")
private int initialSize;
@Value("${datasource.write.minIdle}")
private int minIdle;
@Value("${datasource.write.maxActive}")
private int maxActive;
@Value("${datasource.write.maxWait}")
private int maxWait;
@Value("${datasource.write.timeBetweenEvictionRunsMillis}")
private int timeBetweenEvictionRunsMillis;
@Value("${datasource.write.minEvictableIdleTimeMillis}")
private int minEvictableIdleTimeMillis;
@Value("${datasource.write.validationQuery}")
private String validationQuery;
@Value("${datasource.write.testWhileIdle}")
private boolean testWhileIdle;
@Value("${datasource.write.testOnBorrow}")
private boolean testOnBorrow;
@Value("${datasource.write.testOnReturn}")
private boolean testOnReturn;
@Value("${datasource.write.poolPreparedStatements}")
private boolean poolPreparedStatements;
@Value("${datasource.write.filters}")
private String filtersWrite;
@Value("${datasource.write.connectionProperties}")
private String connectionProperties;
@Bean(name="writeDataSource")
public DataSource writeDataSource(){
DruidDataSource druidDataSource = new DruidDataSource();
druidDataSource.setUrl(dbUrl);
druidDataSource.setUsername(username);
druidDataSource.setPassword(password);
druidDataSource.setDriverClassName(driverClassName);
//configuration
druidDataSource.setInitialSize(initialSize);
druidDataSource.setMinIdle(minIdle);
druidDataSource.setMaxActive(maxActive);
druidDataSource.setMaxWait(maxWait);
druidDataSource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
druidDataSource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
druidDataSource.setValidationQuery(validationQuery);
druidDataSource.setTestWhileIdle(testWhileIdle);
druidDataSource.setTestOnBorrow(testOnBorrow);
druidDataSource.setTestOnReturn(testOnReturn);
druidDataSource.setPoolPreparedStatements(poolPreparedStatements);
try {
druidDataSource.setFilters(filtersWrite);
} catch (SQLException e) {
logger.error("druid configuration initialization filter", e);
}
druidDataSource.setConnectionProperties(connectionProperties);
return druidDataSource;
}
@Bean(name="readDataSource")
public DataSource readDataSource(){
DruidDataSource druidDataSource = new DruidDataSource();
druidDataSource.setUrl(dbUrlRead);
druidDataSource.setUsername(usernameRead);
druidDataSource.setPassword(passwordRead);
druidDataSource.setDriverClassName(driverClassNameRead);
//configuration
druidDataSource.setInitialSize(initialSizeRead);
druidDataSource.setMinIdle(minIdleRead);
druidDataSource.setMaxActive(maxActiveRead);
druidDataSource.setMaxWait(maxWaitRead);
druidDataSource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillisRead);
druidDataSource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillisRead);
druidDataSource.setValidationQuery(validationQueryRead);
druidDataSource.setTestWhileIdle(testWhileIdleRead);
druidDataSource.setTestOnBorrow(testOnBorrowRead);
druidDataSource.setTestOnReturn(testOnReturnRead);
druidDataSource.setPoolPreparedStatements(poolPreparedStatementsRead);
try {
druidDataSource.setFilters(filtersRead);
} catch (SQLException e) {
logger.error("druid configuration initialization filter", e);
}
druidDataSource.setConnectionProperties(connectionPropertiesRead);
return druidDataSource;
}
}
编写 mybaties配置类 MybatiesConfig
package com.demo.springboot_mybatis.config;
import java.util.HashMap;
import java.util.Properties;
import javax.sql.DataSource;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
import com.github.pagehelper.PageHelper;
@Configuration
@Import(MyDruidDataSource.class)
public class MybatiesConfig {
@Value("${spring.datasource.mybatis.base.typeAliases}")
private String typeAliases;
@Bean
public AbstractRoutingDataSource roundRobinDataSouceProxy(
@Qualifier("writeDataSource") DataSource writeDataSource,
@Qualifier("readDataSource") DataSource readDataSource
){
MyAbstractRoutingDataSoruce myAbstractRoutingDataSoruce = new MyAbstractRoutingDataSoruce();
myAbstractRoutingDataSoruce.setDefaultTargetDataSource(writeDataSource);
HashMap<Object, Object> map = new HashMap<Object,Object>();
map.put(DataSourceType.write.getType(), writeDataSource);
map.put(DataSourceType.read.getType(), readDataSource);
myAbstractRoutingDataSoruce.setTargetDataSources(map);
return myAbstractRoutingDataSoruce;
}
@Bean(name = "sqlSessionFactory")
public SqlSessionFactory sqlSessionFactoryBean(AbstractRoutingDataSource roundRobinDataSouceProxy) throws Exception {
SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
bean.setDataSource(roundRobinDataSouceProxy);
if(typeAliases != null && !"".equals(typeAliases)){
typeAliases=","+typeAliases;
}else{
typeAliases="";
}
bean.setTypeAliasesPackage(typeAliases);
//分页插件
PageHelper pageHelper = new PageHelper();
Properties properties = new Properties();
properties.setProperty("reasonable", "true");
properties.setProperty("supportMethodsArguments", "true");
properties.setProperty("returnPageInfo", "check");
properties.setProperty("params", "count=countSql");
pageHelper.setProperties(properties);
//添加插件
bean.setPlugins(new Interceptor[]{pageHelper});
//添加XML目录
ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
try {
//配置mapper对应的xml文件在classpath:下
org.springframework.core.io.Resource[] res = resolver.getResources("classpath:mapper/*.xml");
if(res!= null && res.length > 0 ){
bean.setMapperLocations(res);
}
} catch (Exception e) {
}
return bean.getObject();
}
@Bean
public DataSourceTransactionManager transaction(@Qualifier("writeDataSource") DataSource writeDataSource){
DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager(writeDataSource);
return dataSourceTransactionManager;
}
}
编写mapperScanner
package com.demo.springboot_mybatis.config;
import java.util.Properties;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.AutoConfigureOrder;
import org.springframework.boot.bind.RelaxedPropertyResolver;
import org.springframework.context.EnvironmentAware;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import tk.mybatis.spring.mapper.MapperScannerConfigurer;
/**
* MyBatis扫描接口,使用的tk.mybatis.spring.mapper.MapperScannerConfigurer,如果你不使用通用Mapper,可以改为org.xxx...
*
* @author zgf
* @since 2016-11-14 14:46
*/
//TODO 注意,由于MapperScannerConfigurer执行的比较早,所以必须有下面的注解
@Configuration
@AutoConfigureAfter(MybatiesConfig.class)
public class MyBatisMapperScannerConfig implements EnvironmentAware {
private RelaxedPropertyResolver propertyResolver;
@Override
public void setEnvironment(Environment arg0) {
this.propertyResolver = new RelaxedPropertyResolver(arg0,
"");
}
@Bean
public MapperScannerConfigurer mapperScannerConfigurer() {
MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory");
String mapper = propertyResolver.getProperty("spring.datasource.mybatis.base.mapper");
if(mapper != null && !"".equals(mapper)){
mapper=","+mapper;
}else{
mapper="";
}
mapperScannerConfigurer.setBasePackage(mapper);
Properties properties = new Properties();
properties.setProperty("mappers", "com.demo.util.MyMapper");
properties.setProperty("notEmpty", "false");
properties.setProperty("IDENTITY", "MYSQL");
mapperScannerConfigurer.setProperties(properties);
return mapperScannerConfigurer;
}
}
编写数据源类型 DataSourceType
package com.demo.springboot_mybatis.config;
public enum DataSourceType {
write("write", "写库"), read("read", "读库");
public String type;
public String value;
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
private DataSourceType(String type, String value) {
this.type = type;
this.value = value;
}
}
编写数据源路由 MyAbstractRoutingDataSoruce
package com.demo.springboot_mybatis.config;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class MyAbstractRoutingDataSoruce extends AbstractRoutingDataSource {
@Override
protected Object determineCurrentLookupKey() {
String datatype = DataSourceHolder.threadLocal.get();
if(datatype == null){
return DataSourceType.write.getType();
}
return datatype;
}
}
编写数据源控制类 DataSourceHolder
package com.demo.springboot_mybatis.config;
public class DataSourceHolder {
public static final ThreadLocal<String> threadLocal = new ThreadLocal<String>();
public static void read(){
threadLocal.set(DataSourceType.read.getType());
}
public static void write(){
threadLocal.set(DataSourceType.write.getType());
}
public static String getType(){
return threadLocal.get();
}
}
编写aop 切换数据源 DataSourceAop
package com.demo.springboot_mybatis.config;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;
@Aspect
@Component
public class DataSourceAop {
@Before("execution(* com.demo.springboot_mybatis.service.*.read*(..))")
public void read(){
DataSourceHolder.read();
}
@Before("execution(* com.demo.springboot_mybatis.service.*.insert*(..))")
public void write(){
DataSourceHolder.write();
}
}
编写通用service AbstractBaseService
package com.demo.springboot_mybatis.config;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import com.demo.util.MyMapper;
import tk.mybatis.mapper.entity.Example;
public class AbstractBaseService<CommonMapper extends MyMapper<T>, T extends Object> {
@Autowired
protected CommonMapper mapper;
public List<T> selectAll() {
return mapper.selectAll();
}
public T selectByPrimarikey(Object key) {
return mapper.selectByPrimaryKey(key);
}
public int updateByPrimarikey(T t) {
return mapper.updateByPrimaryKeySelective(t);
}
public int updateByExample(T t,Example example) {
return mapper.updateByExampleSelective(t, example);
}
public int insert(T t) {
return mapper.insert(t);
}
public int insertList(List<T> t) {
return mapper.insertList(t);
}
public int deleteByPrimarikey(Object key) {
return mapper.deleteByPrimaryKey(key);
}
public int deleteByExample(Example example) {
return mapper.deleteByExample(example);
}
public List<T> selectByExample(Example example) {
return mapper.selectByExample(example);
}
}
编写mapper model service
OrganizationName OrganizationNameMapper OrganizationNameService
package com.demo.springboot_mybatis.model;
import java.io.Serializable;
public class OrganizationName implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private Long id ; //机构名称id
private String organizationName; //机构名称
private Long parent_id; //父机构id
private Integer organizationType; //机构类型
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getOrganizationName() {
return organizationName;
}
public void setOrganizationName(String organizationName) {
this.organizationName = organizationName;
}
public Long getParent_id() {
return parent_id;
}
public void setParent_id(Long parent_id) {
this.parent_id = parent_id;
}
public Integer getOrganizationType() {
return organizationType;
}
public void setOrganizationType(Integer organizationType) {
this.organizationType = organizationType;
}
}
package com.demo.springboot_mybatis.mapper;
import com.demo.springboot_mybatis.model.OrganizationName;
import com.demo.util.MyMapper;
public interface OrganizationNameMapper extends MyMapper<OrganizationName>{
}
package com.demo.springboot_mybatis.service;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.demo.springboot_mybatis.config.AbstractBaseService;
import com.demo.springboot_mybatis.mapper.OrganizationNameMapper;
import com.demo.springboot_mybatis.model.OrganizationName;
@Service
public class OrganizationNameService
extends AbstractBaseService<OrganizationNameMapper, OrganizationName> {
@Transactional
public int insertOrganizationName(){
this.selectAll();
OrganizationName org1 = new OrganizationName();
OrganizationName org2 = new OrganizationName();
OrganizationName org3 = new OrganizationName();
OrganizationName org4 = new OrganizationName();
org1.setOrganizationName("105");
org2.setOrganizationName("106");
org3.setOrganizationName("107");
org4.setOrganizationName("108");
this.mapper.insert(org1);
this.mapper.insert(org2);
this.mapper.insert(org3);
this.mapper.insert(org4);
return 1;
}
@Transactional
public int readOrganizationName(){
OrganizationName org1 = new OrganizationName();
OrganizationName org2 = new OrganizationName();
OrganizationName org3 = new OrganizationName();
OrganizationName org4 = new OrganizationName();
org1.setOrganizationName("105");
org2.setOrganizationName("106");
org3.setOrganizationName("107");
org4.setOrganizationName("108");
this.mapper.insert(org1);
this.mapper.insert(org2);
this.mapper.insert(org3);
this.mapper.insert(org4);
return 1;
}
}
编写controlelr进行测试
package com.demo.springboot_mybatis.web;
import javax.servlet.http.HttpServletRequest;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.demo.springboot_mybatis.service.OrganizationNameService;
@RestController
public class RestHelloController {
@Autowired
OrganizationNameService organizationNameService;
@RequestMapping("/insert")
public String insert(HttpServletRequest request) throws Exception{
organizationNameService.insertOrganizationName();
// organizationNameService.readOrganizationName();
return "";
}
}
重新启动我们的项目访问http://localhost:8080/insert