MyException--org.apache.ibatis.exceptions.PersistenceException: ### Error building SqlSession. ###

org.apache.ibatis.exceptions.PersistenceException: 
### Error building SqlSession.
### The error may exist in cn/itcast/mybatis/mapper/OrdersMapperCustom.xml
### The error occurred while processing mapper_resultMap[OrdersUserResultMap]_association[user]
### Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'OrdersUserResultMap'.  Cause: java.lang.ClassNotFoundException: Cannot find class: OrdersUserResultMap
at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:26)
at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:82)
at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:66)
at cn.itcast.mybatis.mapper.OrdersMapperCustomTest.setUp(OrdersMapperCustomTest.java:26)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:27)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:69)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:48)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
at org.junit.runners.ParentRunner.run(ParentRunner.java:292)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'OrdersUserResultMap'.  Cause: java.lang.ClassNotFoundException: Cannot find class: OrdersUserResultMap
at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:109)
at org.apache.ibatis.builder.xml.XMLConfigBuilder.parse(XMLConfigBuilder.java:92)
at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:80)
... 25 more
Caused by: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'OrdersUserResultMap'.  Cause: java.lang.ClassNotFoundException: Cannot find class: OrdersUserResultMap
at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:120)
at org.apache.ibatis.builder.xml.XMLMapperBuilder.parse(XMLMapperBuilder.java:92)
at org.apache.ibatis.builder.annotation.MapperAnnotationBuilder.loadXmlResource(MapperAnnotationBuilder.java:164)
at org.apache.ibatis.builder.annotation.MapperAnnotationBuilder.parse(MapperAnnotationBuilder.java:118)
at org.apache.ibatis.binding.MapperRegistry.addMapper(MapperRegistry.java:71)
at org.apache.ibatis.binding.MapperRegistry.addMappers(MapperRegistry.java:96)
at org.apache.ibatis.binding.MapperRegistry.addMappers(MapperRegistry.java:104)
at org.apache.ibatis.session.Configuration.addMappers(Configuration.java:647)
at org.apache.ibatis.builder.xml.XMLConfigBuilder.mapperElement(XMLConfigBuilder.java:313)
at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:107)
... 27 more
Caused by: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'OrdersUserResultMap'.  Cause: java.lang.ClassNotFoundException: Cannot find class: OrdersUserResultMap
at org.apache.ibatis.builder.BaseBuilder.resolveClass(BaseBuilder.java:103)
at org.apache.ibatis.builder.xml.XMLStatementBuilder.parseStatementNode(XMLStatementBuilder.java:72)
at org.apache.ibatis.builder.xml.XMLMapperBuilder.buildStatementFromContext(XMLMapperBuilder.java:135)
at org.apache.ibatis.builder.xml.XMLMapperBuilder.buildStatementFromContext(XMLMapperBuilder.java:128)
at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:118)
... 36 more
Caused by: org.apache.ibatis.type.TypeException: Could not resolve type alias 'OrdersUserResultMap'.  Cause: java.lang.ClassNotFoundException: Cannot find class: OrdersUserResultMap
at org.apache.ibatis.type.TypeAliasRegistry.resolveAlias(TypeAliasRegistry.java:117)
at org.apache.ibatis.builder.BaseBuilder.resolveAlias(BaseBuilder.java:130)
at org.apache.ibatis.builder.BaseBuilder.resolveClass(BaseBuilder.java:101)
... 40 more
Caused by: java.lang.ClassNotFoundException: Cannot find class: OrdersUserResultMap
at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:190)
at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:89)
at org.apache.ibatis.io.Resources.classForName(Resources.java:256)
at org.apache.ibatis.type.TypeAliasRegistry.resolveAlias(TypeAliasRegistry.java:113)

... 42 more

以上就是我在学习mybatis中，定义statement时，把resultMap定义成了resultType，所以出现了这样的错误信息。

<!-- 查询订单关联查询用户信息,使用resultMap -->
<select id="findOrdersUserResultMap" resultType="OrdersUserResultMap">
SELECT 
orders.*,
  USER.username,
  USER.sex,
  USER.address 
FROM
  orders,
  USER 
WHERE orders.user_id = user.id
</select>

    细节真的很重要，害我检查了好长时间，第二次了，好懵逼的感觉。。。。