基于mybatis+spring的读写分离

来源：互联网发布：淘宝锚点定位跳转编辑：程序博客网时间：2024/04/29 04:08
在SqlSessionTemplate上层进行了封装，根据调用的方法，切换master/slave，但是无法支持事务

package com.xjy.study.spring.mybatis;import java.util.List;import java.util.concurrent.ThreadLocalRandom;import javax.sql.DataSource;import org.apache.ibatis.mapping.Environment;import org.apache.ibatis.session.Configuration;import org.mybatis.spring.SqlSessionTemplate;// 不支持事务public class RWSqlSessionTemplate {    private SqlSessionTemplate sqlSessionTemplate;    private DataSource masterDataSource;    private List<DataSource> slaveDataSources;    private volatile boolean isMaster = true;    public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {        this.sqlSessionTemplate = sqlSessionTemplate;    }    public void setMasterDataSource(DataSource masterDataSource) {        this.masterDataSource = masterDataSource;    }    public void setSlaveDataSources(List<DataSource> slaveDataSources) {        this.slaveDataSources = slaveDataSources;    }    public <T> T selectOne(String statement, Object parameter) {        switchToSlave();        return sqlSessionTemplate.selectOne(statement, parameter);    }    public int update(String statement, Object parameter) {        switchToMaster();        return this.sqlSessionTemplate.update(statement, parameter);      }    private void switchToSlave() {        if(isMaster) {            switchToSlaveDataSource();            isMaster = false;        }    }    private void switchToMaster() {        if(!isMaster) {            switchToMasterDataSource();            isMaster = true;        }    }    private void switchToSlaveDataSource() {        Configuration configuration = this.sqlSessionTemplate.getSqlSessionFactory().getConfiguration();        Environment oldEnvironment = this.sqlSessionTemplate.getSqlSessionFactory().getConfiguration().getEnvironment();        int index = ThreadLocalRandom.current().nextInt(slaveDataSources.size());        Environment newEnvironment = new Environment(oldEnvironment.getId(), oldEnvironment.getTransactionFactory(), slaveDataSources.get(index));        configuration.setEnvironment(newEnvironment);    }    private void switchToMasterDataSource() {        Configuration configuration = this.sqlSessionTemplate.getSqlSessionFactory().getConfiguration();        Environment oldEnvironment = this.sqlSessionTemplate.getSqlSessionFactory().getConfiguration().getEnvironment();        Environment newEnvironment = new Environment(oldEnvironment.getId(), oldEnvironment.getTransactionFactory(), this.masterDataSource);        configuration.setEnvironment(newEnvironment);    }}
0 0