mybatis-4 mybatis与spring结合使用及原理解析

<dependencies>

  <dependency>

  <groupid>org. spring framework</groupid>

  <artifactid>spring-context</artifactid>

  <version> 5.0 . 8 .release</version>

  </dependency>

  <dependency>

  <groupid>org. mybatis </groupid>

  <artifactid>mybatis-spring</artifactid>

  <version> 2.0 . 0 </version>

  </dependency>

  <dependency>

  <groupid>org.mybatis</groupid>

  <artifactid>mybatis</artifactid>

  <version> 3.4 . 6 </version>

  </dependency>

  <dependency>

  <groupid>mysql</groupid>

  <artifactid>mysql-connector-java</artifactid>

  <version> 5.1 . 34 </version>

  </dependency>

  <dependency>

  <groupid>org.springframework</groupid>

  <artifactid>spring-jdbc</artifactid>

  <version> 5.0 . 8 .release</version>

  </dependency>

  <dependency>

  <groupid>org.springframework</groupid>

  <artifactid>spring-core</artifactid>

  <version> 5.0 . 8 .release</version>

  </dependency>

</dependencies>

package com.config;

import org.mybatis.spring.sqlsessionfactorybean;

import org.mybatis.spring.annotation.mapperscan;

import org.springframework.beans.factory.annotation.autowired;

import org.springframework.context.annotation.bean;

import org.springframework.context.annotation测试数据ponentscan;

import org.springframework.context.annotation.configuration;

import org.springframework.jdbc.datasource.drivermanagerdatasource;

import javax.sql.datasource;

@configuration

@mapperscan ( "com.dao" ) //注解 与xml<mybatis:scan base-package="org.mybatis.spring.sample.mapper" />

//注册包中递归搜索映射器

@componentscan ( "com" ) //注册bean

public class appconfig {

  @bean

  @autowired

  public sqlsessionfactorybean sqlsessionfactorybean(datasource datasource ){

  sqlsessionfactorybean sqlsessionfactorybean = new sqlsessionfactorybean();

  sqlsessionfactorybean.setdatasource(datasource);

  return sqlsessionfactorybean;

  }

  @bean

  public datasource getdatasource(){

  drivermanagerdatasource datasource = new drivermanagerdatasource();

  datasource.setdriverclassname( "com.mysql.jdbc.driver" );

  datasource.setusername( "root" );

  datasource.setpassword( "110226wjwj" );

  datasource.seturl( "jdbc:mysql://localhost:3306/mybatis_wjw?useunicode=true&characterencoding=utf-8&usessl=false" );

  return datasource;

  }

}

package com.dao;

import org.apache.ibatis.annotations.select;

import java.util.list;

import java.util.map;

public interface userdao {

  @select ( "select * from t_user where tid =3" )

  public list<map> query();

}

package com.service;

import com.dao.userdao;

import org.springframework.beans.factory.annotation.autowired;

import org.springframework.stereotype.service;

//spring注解中service与component意思差不多，区别在于component是中立注解，而service是业务逻辑层的注解

//@component

@service

public class userservice {

  @autowired

  userdao userdao;

  public void query(){

  system.out.println(userdao.query());

  }

}

package com.test;

import com.config.appconfig;

import com.service.userservice;

import org.springframework.context.annotation.annotationconfigapplicationcontext;

public class maintest {

  public static void main(string args[]){

  annotationconfigapplicationcontext acc = new annotationconfigapplicationcontext(appconfig. class );

  userservice us = acc.getbean(userservice. class );

  us.query();

  }

}

public <t> t selectone(string statement, object parameter) {

  list<t> list = this .selectlist(statement, parameter);

  if (list.size() == 1 ) {

   return list.get( 0 );

  } else if (list.size() > 1 ) {

   throw new toomanyresultsexception( "expected one result (or null) to be returned by selectone(), but found: " + list.size());

  } else {

   return null ;

  }

  }

public <e> list<e> selectlist(string statement, object parameter, rowbounds rowbounds) {

  list var5;

  try {

   mappedstatement ms = this .configuration.getmappedstatement(statement);

   var5 = this .executor.query(ms, this .wrapcollection(parameter), rowbounds, executor.no_result_handler);

  } catch (exception var9) {

   throw exceptionfactory.wrapexception( "error querying database. cause: " + var9, var9);

  } finally {

   errorcontext.instance().reset();

  }

  return var5;

  }

protected set<beandefinitionholder> doscan(string... basepackages) {

  assert .notempty(basepackages, "at least one base package must be specified" );

  set<beandefinitionholder> beandefinitions = new linkedhashset();

  string[] var3 = basepackages;

  int var4 = basepackages.length;

  for ( int var5 = 0 ; var5 < var4; ++var5) {

   string basepackage = var3[var5];

   set<beandefinition> candidates = this .findcandidatecomponents(basepackage);

   iterator var8 = candidates.iterator();

   while (var8.hasnext()) {

   beandefinition candidate = (beandefinition)var8.next();

   scopemetadata scopemetadata = this .scopemetadataresolver.resolvescopemetadata(candidate);

   candidate.setscope(scopemetadata.getscopename());

   string beanname = this .beannamegenerator.generatebeanname(candidate, this .registry);

   if (candidate instanceof abstractbeandefinition) {

    this .postprocessbeandefinition((abstractbeandefinition)candidate, beanname);

   }

   if (candidate instanceof annotatedbeandefinition) {

    annotationconfigutils.processcommondefinitionannotations((annotatedbeandefinition)candidate);

   }

   if ( this .checkcandidate(beanname, candidate)) {

    beandefinitionholder definitionholder = new beandefinitionholder(candidate, beanname);

    definitionholder = annotationconfigutils.applyscopedproxymode(scopemetadata, definitionholder, this .registry);

    beandefinitions.add(definitionholder);

    this .registerbeandefinition(definitionholder, this .registry);

   }

   }

  }

  return beandefinitions;

  }

public interface executor {

  resulthandler no_result_handler = null ;

  int update(mappedstatement var1, object var2) throws sqlexception;

  <e> list<e> query(mappedstatement var1, object var2, rowbounds var3, resulthandler var4, cachekey var5, boundsql var6) throws sqlexception;

  <e> list<e> query(mappedstatement var1, object var2, rowbounds var3, resulthandler var4) throws sqlexception;

  <e> cursor<e> querycursor(mappedstatement var1, object var2, rowbounds var3) throws sqlexception;

  list<batchresult> flushstatements() throws sqlexception;

  void commit( boolean var1) throws sqlexception;

  void rollback( boolean var1) throws sqlexception;

  cachekey createcachekey(mappedstatement var1, object var2, rowbounds var3, boundsql var4);

  boolean iscached(mappedstatement var1, cachekey var2);

  void clearlocalcache();

  void deferload(mappedstatement var1, metaobject var2, string var3, cachekey var4, class <?> var5);

  transaction gettransaction();

  void close( boolean var1);

  boolean isclosed();

  void setexecutorwrapper(executor var1);

}