由于公司业务划分了多个数据库，开发一个项目会同事调用多个库，经过学习我们采用了注解+aop的方式实现的
1.首先定义一个注解类
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@retention(retentionpolicy.runtime)@target(elementtype.method)public @interface targetdatasource { string value();//此处接收的是数据源的名称} |
2.然后建一个配置类，这个在项目启动时会加载数据源，一开始采用了hikaricp，查资料说是最快性能最好的，然后又发现了阿里的druid，这个功能比较全面，而且性能也还可以，最主要他还有监控功能，具体实现看如下代码
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package com.example.demo.datasource; import com.alibaba.druid.pool.druiddatasource;import com.alibaba.druid.support.http.statviewservlet;import com.alibaba.druid.support.http.webstatfilter;import com.example.demo.datasource.dynamicdatasource;import com.zaxxer.hikari.hikariconfig;import com.zaxxer.hikari.hikaridatasource;import lombok.extern.slf4j.slf4j;import org.mybatis.spring.annotation.mapperscan;import org.springframework.beans.factory.annotation.autowired;import org.springframework.beans.factory.annotation.qualifier;import org.springframework.beans.factory.annotation.value;import org.springframework.boot.web.servlet.filterregistrationbean;import org.springframework.boot.web.servlet.servletregistrationbean;import org.springframework.context.annotation.bean;import org.springframework.context.annotation.configuration;import org.springframework.jdbc.datasource.datasourcetransactionmanager;import org.springframework.scheduling.annotation.enablescheduling;import org.springframework.scheduling.annotation.scheduled;import org.springframework.transaction.platformtransactionmanager;import org.w3c.dom.nodelist;import org.w3c.dom.document;import org.w3c.dom.element;import org.w3c.dom.node; import javax.servlet.annotation.webinitparam;import javax.servlet.annotation.webservlet;import javax.sql.datasource;import javax.xml.parsers.documentbuilder;import javax.xml.parsers.documentbuilderfactory;import java.lang.reflect.field;import java.lang.reflect.method;import java.util.hashmap;import java.util.map;import java.io.file;import com.alibaba.druid.support.http.statviewservlet;/** * author: wangchao * version： * date: 2017/9/11 * description:数据源配置 * modification history: * date author version description * -------------------------------------------------------------- * why & what is modified: */ @configuration@enableschedulingpublic class datasourceconfig { /*@autowired private dbproperties properties;*/ @value("${datasource.filepath}") private string filepath;//数据源配置 @bean(name = "datasource") public datasource datasource() { //按照目标数据源名称和目标数据源对象的映射存放在map中 map<object, object> targetdatasources = new hashmap<>(); //查找xml数据连接字符串 targetdatasources=getdatamap(filepath); //动态获取dbproperties类申明的属性 /*field[] fields=properties.getclass().getdeclaredfields(); for(int i=0;i<fields.length;i++) { targetdatasources.put(fields[i].getname(), getfieldvaluebyname(fields[i].getname(),properties)); }*/ //采用是想abstractroutingdatasource的对象包装多数据源 dynamicdatasource datasource = new dynamicdatasource(); datasource.settargetdatasources(targetdatasources); //设置默认的数据源，当拿不到数据源时，使用此配置 //datasource.setdefaulttargetdatasource(properties.getuzaitravel()); return datasource; } @bean public platformtransactionmanager txmanager() { return new datasourcetransactionmanager(datasource()); } /** *获取数据源集合 */ private map<object, object> getdatamap(string fiepath) { try { map<object, object> targetdatasources = new hashmap<>(); file xmlfile = new file(fiepath); documentbuilderfactory builderfactory = documentbuilderfactory.newinstance(); documentbuilder builder = builderfactory.newdocumentbuilder(); document doc = builder.parse(xmlfile); doc.getdocumentelement().normalize(); system.out.println("root element: " + doc.getdocumentelement().getnodename()); nodelist nlist = doc.getelementsbytagname("db"); for(int i = 0 ; i<nlist.getlength();i++) { node node = nlist.item(i); element ele = (element)node; /*hikariconfig config = new hikariconfig(); config.setdriverclassname(ele.getelementsbytagname("driver-class").item(0).gettextcontent()); config.setjdbcurl(ele.getelementsbytagname("jdbc-url").item(0).gettextcontent()); config.setusername(ele.getelementsbytagname("username").item(0).gettextcontent()); config.setpassword(ele.getelementsbytagname("password").item(0).gettextcontent()); //config.adddatasourceproperty("password", ele.getelementsbytagname("password").item(0).gettextcontent()); hikaridatasource datasource = new hikaridatasource(config);*/ druiddatasource datasource = new druiddatasource(); datasource.setdriverclassname(ele.getelementsbytagname("driver-class").item(0).gettextcontent()); datasource.setusername(ele.getelementsbytagname("username").item(0).gettextcontent()); datasource.setpassword(ele.getelementsbytagname("password").item(0).gettextcontent()); datasource.seturl(ele.getelementsbytagname("jdbc-url").item(0).gettextcontent()); datasource.setinitialsize(5); datasource.setminidle(1); datasource.setmaxactive(10);// 启用监控统计功能 datasource.setfilters("stat");//设置是否显示sql语句 targetdatasources.put(ele.getelementsbytagname("databasename").item(0).gettextcontent(), datasource); } return targetdatasources; } catch (exception ex) { return null; } } //访问的ip @value("${druid.ip}") private string ip; //登录名 @value("${druid.druidlgoinname}") private string druidlgoinname; //密码 @value("${druid.druidlgoinpassword}") private string druidlgoinpassword; @bean public servletregistrationbean druidstatviewservle() { //org.springframework.boot.context.embedded.servletregistrationbean提供类的进行注册. servletregistrationbean servletregistrationbean = new servletregistrationbean(new statviewservlet(), "/druid/*"); //添加初始化参数：initparams //白名单： servletregistrationbean.addinitparameter("allow",ip); //ip黑名单 (存在共同时，deny优先于allow) : 如果满足deny的话提示:sorry, you are not permitted to view this page. // servletregistrationbean.addinitparameter("deny", "192.168.1.73"); //登录查看信息的账号密码. servletregistrationbean.addinitparameter("loginusername",druidlgoinname); servletregistrationbean.addinitparameter("loginpassword",druidlgoinpassword); //是否能够重置数据. servletregistrationbean.addinitparameter("resetenable","false"); return servletregistrationbean; } /** * 注册一个：filterregistrationbean * @return */ @bean public filterregistrationbean druidstatfilter2(){ 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/*"); return filterregistrationbean; } } |
3.动态数据源，从之前已加载的数据源中选取，dynamicdatasource和dynamicdatasourceholder配合使用
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public class dynamicdatasource extends abstractroutingdatasource{ //数据源路由，此方用于产生要选取的数据源逻辑名称 @override protected object determinecurrentlookupkey() { //从共享线程中获取数据源名称 return dynamicdatasourceholder.getdatasource(); }}public class dynamicdatasourceholder { /** * 本地线程共享对象 */ private static final threadlocal<string> thread_local = new threadlocal<>(); public static void putdatasource(string name) { thread_local.set(name); } public static string getdatasource() { return thread_local.get(); } public static void removedatasource() { thread_local.remove(); }} |
4.就是使用aop，在dao层切换数据源
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@component@aspectpublic class datasourceaspect { //切换放在mapper接口的方法上，所以这里要配置aop切面的切入点 @pointcut("execution( * com.example.demo.dao.*.*(..))") public void datasourcepointcut() { } @before("datasourcepointcut()") public void before(joinpoint joinpoint) { object target = joinpoint.gettarget(); string method = joinpoint.getsignature().getname(); class<?>[] clazz = target.getclass().getinterfaces(); class<?>[] parametertypes = ((methodsignature) joinpoint.getsignature()).getmethod().getparametertypes(); try { method m = clazz[0].getmethod(method, parametertypes); //如果方法上存在切换数据源的注解，则根据注解内容进行数据源切换 if (m != null && m.isannotationpresent(targetdatasource.class)) { targetdatasource data = m.getannotation(targetdatasource.class); string datasourcename = data.value(); dynamicdatasourceholder.putdatasource(datasourcename); } else { } } catch (exception e) { } } //执行完切面后，将线程共享中的数据源名称清空 @after("datasourcepointcut()") public void after(joinpoint joinpoint){ dynamicdatasourceholder.removedatasource(); }} |
数据连接都配置在xml里面
xml路径在配置文件里面配置，这样适用读写分离和多个不同的数据源，而且多个项目可以共用这一个配置
最后引用注解，需要注意的是注解的数据库名称和xml里面databasename节点是一一对应的，可以随便自定义，比如读写是一个数据库名字，这时候就可以定义成pringtest_r表示读库
至此多数据源就配置完成，至于阿里的druid下次再分享，代码都贴出来，如果大家感觉还有哪些不足的地方，欢迎指正。
以上这篇spring boot+mybatis 多数据源切换(实例讲解)就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持服务器之家。
原文链接：http://www.cnblogs.com/ok123/archive/2017/09/14/7523106.html
