本文介绍基于spring+mybatis+atomikos+jta实现分布式事务，由程序动态切换数据源，通过atomikos可实现分布式事务一致性。
版本：spring-3.2.9.RELEASE、mybatis-3.4.4、atomikos-4.0.5、jdk1.8
1，maven配置文件pom.xml如下：
junit
junit
4.12
test
hamcrest-core
org.hamcrest
org.hamcrest
hamcrest-all
1.3
test
org.mockito
mockito-core
1.9.5
test
hamcrest-core
org.hamcrest
com.jayway.jsonpath
json-path
0.8.1
test
org.springframework
spring-aop
${spring.version}
org.springframework
spring-beans
${spring.version}
org.springframework
spring-context
${spring.version}
org.springframework
spring-core
${spring.version}
org.springframework
spring-expression
${spring.version}
org.springframework
spring-web
${spring.version}
org.springframework
spring-webmvc
${spring.version}
org.springframework
spring-webmvc-portlet
${spring.version}
org.springframework
spring-tx
${spring.version}
org.springframework
spring-jdbc
${spring.version}
org.springframework
spring-test
3.2.18.RELEASE
org.springframework
spring-struts
${spring.version}
org.mybatis
mybatis
3.4.4
org.mybatis
mybatis-spring
1.3.1
mysql
mysql-connector-java
5.1.27
com.atomikos
transactions-jdbc
4.0.5
javax.transaction
jta
1.1
org.codehaus.jackson
jackson-mapper-asl
1.9.13
org.codehaus.jackson
jackson-core-asl
1.9.13
org.aspectj
aspectjweaver
1.8.13
log4j
log4j
1.2.16
javax.servlet
servlet-api
2.5
provided
2，数据库连接配置文件：jdbc.properties
jdbc.xaDataSourceClassName=com.mysql.jdbc.jdbc2.optional.MysqlXADataSource
validationQuery=select 1
ds1.jdbc.url=jdbc:mysql://xx.xx.xx.xx:3306/test1?characterEncoding=UTF-8
ds1.jdbc.username=xxxx
ds1.jdbc.password=xxxx
ds2.jdbc.url=jdbc:mysql://xx.xx.xx.xx:3306/test2?characterEncoding=UTF-8
ds2.jdbc.username=xxxx
ds2.jdbc.password=xxxx3，atomikos配置文件：jta.properties
com.atomikos.icatch.service=com.atomikos.icatch.standalone.UserTransactionServiceFactory
com.atomikos.icatch.console_file_name=tm.release.out
com.atomikos.icatch.log_base_name=tm.releaselog
com.atomikos.icatch.tm_unique_name=com.atomikos.spring.jdbc.tm.release
com.atomikos.icatch.console_log_level=INFO4，spring-datasource-jta.xml
classpath*:jdbc.properties
${ds1.jdbc.url}
${ds1.jdbc.username}
${ds1.jdbc.password}
${ds2.jdbc.url}
${ds2.jdbc.username}
${ds2.jdbc.password}
true
5，spring-mybatis-dynamic.xml
classpath:mybatis/model/*.xml
classpath:mybatis/model/*.xml
6，编写mybatis.model代码，HelloDO.java、 HelloMapper.java、HelloMapper.xml
HelloDO.java
package mybatis.model;
public class HelloDO {
private Long id;
private String name;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
HelloMapper.java
package mybatis.model;
import org.springframework.stereotype.Repository;
@Repository(value="helloMapper")
public interface HelloMapper {
public void insert(HelloDO hello);
}
HelloMapper.xml
insert into
HELLO(ID,NAME)
values(#{id},#{name})
7，编写service类：mybatis.dynamic.service.HelloWorldServiceDynamic.java
package mybatis.dynamic.service;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import mybatis.model.HelloDO;
import mybatis.model.HelloMapper;
@Service("helloWorldServiceDynamic")
public class HelloWorldServiceDynamic {
@Autowired
private HelloMapper helloMapper;
public void addHello(HelloDO helloDO) {
// TODO Auto-generated method stub
helloMapper.insert(helloDO);
}
}8，编写controller类：mybatis.dynamic.controler.HelloWorldController.java
package mybatis.dynamic.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import mybatis.dynamic.service.HelloWorldServiceDynamic;
import mybatis.model.HelloDO;
import spring.jta.util.DataSourceContextHolder;
@Controller(value = "helloWorldController")
@RequestMapping(value="/hello")
public class HelloWorldControler {
@Autowired
private HelloWorldServiceDynamic helloWorldServiceDynamic;
@Transactional
@RequestMapping(value="create_dynamic",method=RequestMethod.POST)
public @ResponseBody long createHelloDynamic(@RequestBody HelloDO helloDO) {
DataSourceContextHolder.setDBType("dataSource");
helloWorldServiceDynamic.addHello(helloDO);
DataSourceContextHolder.setDBType("dataSource2");
helloWorldServiceDynamic.addHello(helloDO);
return helloDO.getId();
}
}9，编写测试类：HelloWorldControlerDynamicTest.java
package mybatis.controller;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.ObjectWriter;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4Cla***unner;
import org.springframework.test.context.web.WebAppConfiguration;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;
import mybatis.model.HelloDO;
@RunWith(SpringJUnit4Cla***unner.class)
@WebAppConfiguration
@ContextConfiguration({ "classpath:spring-datasource-jta.xml", "classpath:spring-mybatis-dynamic.xml" })
public class HelloWorldControlerDynamicTest {
@Autowired
private WebApplicationContext context;
private MockMvc mocMvc;
@Before
public void setUp() throws Exception {
mocMvc = MockMvcBuilders.webAppContextSetup(context).build();
}
@Test
public void test() throws Exception {
String data = "{\"id\":1,\"name\":\"abc\"}";
HelloDO hello = new HelloDO();
hello.setId(1L);
hello.setName("abc");
ObjectMapper mapper = new ObjectMapper();
ObjectWriter ow = mapper.writer().withDefaultPrettyPrinter();
java.lang.String requestJson = ow.writeValueAsString(hello);
mocMvc.perform(post("/hello/create_dynamic").contentType(MediaType.APPLICATION_JSON).content(data)).andExpect(status().isOk());
}
}10，编写数据源切换类 DataSourceContextHolder.java
package spring.jta.util;
public class DataSourceContextHolder {
private static final ThreadLocal contextHolder = new ThreadLocal();
public static void setDBType(String dbType) {
contextHolder.set(dbType);
}
public static String getDBType() {
return ((String) contextHolder.get());
}
public static void clearDBType() {
contextHolder.remove();
}
} 11，编写CustomSqlSessionTemplate.java，该类扩展SqlSessionTemplate，结合DataSourceContextHolder实现sqlSession的切换
package spring.jta.util;
import static java.lang.reflect.Proxy.newProxyInstance;
import static org.apache.ibatis.reflection.ExceptionUtil.unwrapThrowable;
import static org.mybatis.spring.SqlSessionUtils.closeSqlSession;
import static org.mybatis.spring.SqlSessionUtils.getSqlSession;
import static org.mybatis.spring.SqlSessionUtils.isSqlSessionTransactional;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.exceptions.PersistenceException;
import org.apache.ibatis.executor.BatchResult;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.MyBatisExceptionTranslator;
import org.mybatis.spring.SqlSessionTemplate;
import org.springframework.dao.support.PersistenceExceptionTranslator;
import org.springframework.util.Assert;
/**
* function: 继承SqlSessionTemplate 重写相关方法
* @author hoojo
* @createDate 2013-10-18 下午03:07:46
* @file CustomSqlSessionTemplate.java
* @package com.hoo.framework.mybatis.support
* @project SHMB
* @blog http://blog.csdn.net/IBM_hoojo
* @email [email protected]
* @version 1.0
*/
public class CustomSqlSessionTemplate extends SqlSessionTemplate {
private final SqlSessionFactory sqlSessionFactory;
private final ExecutorType executorType;
private final SqlSession sqlSessionProxy;
private final PersistenceExceptionTranslator exceptionTranslator;
private Map targetSqlSessionFactorys;
private SqlSessionFactory defaultTargetSqlSessionFactory;
public void setTargetSqlSessionFactorys(Map targetSqlSessionFactorys) {
this.targetSqlSessionFactorys = targetSqlSessionFactorys;
}
public void setDefaultTargetSqlSessionFactory(SqlSessionFactory defaultTargetSqlSessionFactory) {
this.defaultTargetSqlSessionFactory = defaultTargetSqlSessionFactory;
}
public CustomSqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
this(sqlSessionFactory, sqlSessionFactory.getConfiguration().getDefaultExecutorType());
}
public CustomSqlSessionTemplate(SqlSessionFactory sqlSessionFactory, ExecutorType executorType) {
this(sqlSessionFactory, executorType, new MyBatisExceptionTranslator(sqlSessionFactory.getConfiguration()
.getEnvironment().getDataSource(), true));
}
public CustomSqlSessionTemplate(SqlSessionFactory sqlSessionFactory, ExecutorType executorType,
PersistenceExceptionTranslator exceptionTranslator) {
super(sqlSessionFactory, executorType, exceptionTranslator);
this.sqlSessionFactory = sqlSessionFactory;
this.executorType = executorType;
this.exceptionTranslator = exceptionTranslator;
this.sqlSessionProxy = (SqlSession) newProxyInstance(
SqlSessionFactory.class.getClassLoader(),
new Class[] { SqlSession.class },
new SqlSessionInterceptor());
this.defaultTargetSqlSessionFactory = sqlSessionFactory;
}
@Override
public SqlSessionFactory getSqlSessionFactory() {
SqlSessionFactory targetSqlSessionFactory = targetSqlSessionFactorys.get(DataSourceContextHolder.getDBType());
if (targetSqlSessionFactory != null) {
return targetSqlSessionFactory;
} else if (defaultTargetSqlSessionFactory != null) {
return defaultTargetSqlSessionFactory;
} else {
Assert.notNull(targetSqlSessionFactorys, "Property 'targetSqlSessionFactorys' or 'defaultTargetSqlSessionFactory' are required");
Assert.notNull(defaultTargetSqlSessionFactory, "Property 'defaultTargetSqlSessionFactory' or 'targetSqlSessionFactorys' are required");
}
return this.sqlSessionFactory;
}
public List getAllConfigurations() {
List list = new ArrayList();
for(Map.Entry entry : targetSqlSessionFactorys.entrySet()) {
SqlSessionFactory sqlSessionFactory = entry.getValue();
list.add(sqlSessionFactory.getConfiguration());
}
return list;
}
@Override
public Configuration getConfiguration() {
return this.getSqlSessionFactory().getConfiguration();
}
public ExecutorType getExecutorType() {
return this.executorType;
}
public PersistenceExceptionTranslator getPersistenceExceptionTranslator() {
return this.exceptionTranslator;
}
/**
* {@inheritDoc}
*/
public T selectOne(String statement) {
return this.sqlSessionProxy. selectOne(statement);
}
/**
* {@inheritDoc}
*/
public T selectOne(String statement, Object parameter) {
return this.sqlSessionProxy. selectOne(statement, parameter);
}
/**
* {@inheritDoc}
*/
public Map selectMap(String statement, String mapKey) {
return this.sqlSessionProxy. selectMap(statement, mapKey);
}
/**
* {@inheritDoc}
*/
public Map selectMap(String statement, Object parameter, String mapKey) {
return this.sqlSessionProxy. selectMap(statement, parameter, mapKey);
}
/**
* {@inheritDoc}
*/
public Map selectMap(String statement, Object parameter, String mapKey, RowBounds rowBounds) {
return this.sqlSessionProxy. selectMap(statement, parameter, mapKey, rowBounds);
}
/**
* {@inheritDoc}
*/
public List selectList(String statement) {
return this.sqlSessionProxy. selectList(statement);
}
/**
* {@inheritDoc}
*/
public List selectList(String statement, Object parameter) {
return this.sqlSessionProxy. selectList(statement, parameter);
}
/**
* {@inheritDoc}
*/
public List selectList(String statement, Object parameter, RowBounds rowBounds) {
return this.sqlSessionProxy. selectList(statement, parameter, rowBounds);
}
/**
* {@inheritDoc}
*/
public void select(String statement, ResultHandler handler) {
this.sqlSessionProxy.select(statement, handler);
}
/**
* {@inheritDoc}
*/
public void select(String statement, Object parameter, ResultHandler handler) {
this.sqlSessionProxy.select(statement, parameter, handler);
}
/**
* {@inheritDoc}
*/
public void select(String statement, Object parameter, RowBounds rowBounds, ResultHandler handler) {
this.sqlSessionProxy.select(statement, parameter, rowBounds, handler);
}
/**
* {@inheritDoc}
*/
public int insert(String statement) {
return this.sqlSessionProxy.insert(statement);
}
/**
* {@inheritDoc}
*/
public int insert(String statement, Object parameter) {
return this.sqlSessionProxy.insert(statement, parameter);
}
/**
* {@inheritDoc}
*/
public int update(String statement) {
return this.sqlSessionProxy.update(statement);
}
/**
* {@inheritDoc}
*/
public int update(String statement, Object parameter) {
return this.sqlSessionProxy.update(statement, parameter);
}
/**
* {@inheritDoc}
*/
public int delete(String statement) {
return this.sqlSessionProxy.delete(statement);
}
/**
* {@inheritDoc}
*/
public int delete(String statement, Object parameter) {
return this.sqlSessionProxy.delete(statement, parameter);
}
/**
* {@inheritDoc}
*/
public T getMapper(Class type) {
return getConfiguration().getMapper(type, this);
}
/**
* {@inheritDoc}
*/
public void commit() {
throw new UnsupportedOperationException("Manual commit is not allowed over a Spring managed SqlSession");
}
/**
* {@inheritDoc}
*/
public void commit(boolean force) {
throw new UnsupportedOperationException("Manual commit is not allowed over a Spring managed SqlSession");
}
/**
* {@inheritDoc}
*/
public void rollback() {
throw new UnsupportedOperationException("Manual rollback is not allowed over a Spring managed SqlSession");
}
/**
* {@inheritDoc}
*/
public void rollback(boolean force) {
throw new UnsupportedOperationException("Manual rollback is not allowed over a Spring managed SqlSession");
}
/**
* {@inheritDoc}
*/
public void close() {
throw new UnsupportedOperationException("Manual close is not allowed over a Spring managed SqlSession");
}
/**
* {@inheritDoc}
*/
public void clearCache() {
this.sqlSessionProxy.clearCache();
}
/**
* {@inheritDoc}
*/
public Connection getConnection() {
return this.sqlSessionProxy.getConnection();
}
/**
* {@inheritDoc}
* @since 1.0.2
*/
public List flushStatements() {
return this.sqlSessionProxy.flushStatements();
}
/**
* Proxy needed to route MyBatis method calls to the proper SqlSession got from Spring's Transaction Manager It also
* unwraps exceptions thrown by {@code Method#invoke(Object, Object...)} to pass a {@code PersistenceException} to
* the {@code PersistenceExceptionTranslator}.
*/
private class SqlSessionInterceptor implements InvocationHandler {
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
final SqlSession sqlSession = getSqlSession(
CustomSqlSessionTemplate.this.getSqlSessionFactory(),
CustomSqlSessionTemplate.this.executorType,
CustomSqlSessionTemplate.this.exceptionTranslator);
try {
Object result = method.invoke(sqlSession, args);
if (!isSqlSessionTransactional(sqlSession, CustomSqlSessionTemplate.this.getSqlSessionFactory())) {
// force commit even on non-dirty sessions because some databases require
// a commit/rollback before calling close()
sqlSession.commit(true);
}
return result;
} catch (Throwable t) {
Throwable unwrapped = unwrapThrowable(t);
if (CustomSqlSessionTemplate.this.exceptionTranslator != null && unwrapped instanceof PersistenceException) {
Throwable translated = CustomSqlSessionTemplate.this.exceptionTranslator
.translateExceptionIfPossible((PersistenceException) unwrapped);
if (translated != null) {
unwrapped = translated;
}
}
throw unwrapped;
} finally {
closeSqlSession(sqlSession, CustomSqlSessionTemplate.this.getSqlSessionFactory());
}
}
}
}