typeAliases

mybatis的xml文件中需要写类的全限定名，较繁琐，可以配置自动扫描包路径给类配置别名，两种配置方式。

方式一：

mybatis-config.xml中配置

<typeAliases>
　　<package name="com.xiaomu.context.config.model"/>
</typeAliases>

此配置不支持多路径配置，不支持通配符配置，不灵活（个人实验不行）

 

方式二：

SqlSessionFactory中配置typeAliasesPackage属性

<bean id="mybatisSqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="configLocation" value="classpath:mybatis-config.xml"/>
    <property name="typeAliasesPackage" value="com.xiaomu.content.model,com.test.model"/>
    <property name="mapperLocations">
        <list>
            <value>classpath*:sql/**/*.xml</value>
        </list>
    </property>
</bean>

 

此种方式支持多路径，逗号隔开，但是若有新路径新增需要再次配置，不知情情况下容易疏漏，最好是通配符配置，目前不支持，可通过继承重写包路径读取方式来实现支持通配符配置
配置如下：

<bean id="mybatisSqlSessionFactory" class="com.xiaomu.jdbc.util.PackagesSqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="configLocation" value="classpath:mybatis-config.xml"/>
    <property name="typeAliasesPackage" value="com.xiaomu.**.model"/>
    <property name="mapperLocations">
        <list>
            <value>classpath*:sql/**/*.xml</value>
        </list>
    </property>
</bean>

 

java实现类代码：

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.lang3.StringUtils;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.core.type.classreading.CachingMetadataReaderFactory;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.core.type.classreading.MetadataReaderFactory;
import org.springframework.util.ClassUtils;

public class PackagesSqlSessionFactoryBean extends SqlSessionFactoryBean {

    private static final Logger logger = LoggerFactory.getLogger(PackagesSqlSessionFactoryBean.class);
    
    static final String DEFAULT_RESOURCE_PATTERN = "**/*.class";
    
    @Override    
    public void setTypeAliasesPackage(String typeAliasesPackage) {    
        ResourcePatternResolver resolver = (ResourcePatternResolver) new PathMatchingResourcePatternResolver();    
        MetadataReaderFactory metadataReaderFactory = new CachingMetadataReaderFactory(resolver);    
        typeAliasesPackage = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX +    
                ClassUtils.convertClassNameToResourcePath(typeAliasesPackage) + "/" + DEFAULT_RESOURCE_PATTERN;    
    
        //将加载多个绝对匹配的所有Resource    
        //将首先通过ClassLoader.getResource("META-INF")加载非模式路径部分    
        //然后进行遍历模式匹配    
        try {
            List<String> result = new ArrayList<String>();
            Resource[] resources =  resolver.getResources(typeAliasesPackage);
            if(resources != null && resources.length > 0){
                MetadataReader metadataReader = null;
                for(Resource resource : resources){
                    if(resource.isReadable()){
                       metadataReader =  metadataReaderFactory.getMetadataReader(resource);
                        try {
                            result.add(Class.forName(metadataReader.getClassMetadata().getClassName()).getPackage().getName());    
                        } catch (ClassNotFoundException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
            if(result.size() > 0) {
                super.setTypeAliasesPackage(StringUtils.join(result.toArray(), ","));
            }else{
                logger.warn("参数typeAliasesPackage:"+typeAliasesPackage+"，未找到任何包");
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }    
}