java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for org.fkit

错误信息：

Exception in thread "main" org.apache.ibatis.exceptions.PersistenceException:
### Error querying database. Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for org.fkit.mapper.ArticleMapper.selectArticleByOrderId
### The error may exist in org/fkit/mapper/OrderMapper.xml
### The error may involve org.fkit.mapper.OrderMapper.selectOrderById-Inline
### The error occurred while setting parameters
### SQL: select u.*,o.id as oid,code,total,user_id from tb_user u,tb_order o where u.id=o.user_id and o.id = ?
### Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for org.fkit.mapper.ArticleMapper.selectArticleByOrderId
at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:26)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:111)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:102)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:66)
at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:68)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:52)
at com.sun.proxy.$Proxy19.selectOrderById(Unknown Source)
at org.fkit.test.ManyToManyTest.testSelectOrderById(ManyToManyTest.java:45)
at org.fkit.test.ManyToManyTest.main(ManyToManyTest.java:28)
Caused by: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for org.fkit.mapper.ArticleMapper.selectArticleByOrderId
at org.apache.ibatis.session.Configuration$StrictMap.get(Configuration.java:797)
at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:631)
at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:624)
at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.getNestedQueryMappingValue(DefaultResultSetHandler.java:593)
at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.getPropertyMappingValue(DefaultResultSetHandler.java:380)
at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.applyPropertyMappings(DefaultResultSetHandler.java:364)
at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.getRowValue(DefaultResultSetHandler.java:745)
at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleRowValuesForNestedResultMap(DefaultResultSetHandler.java:713)
at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleRowValues(DefaultResultSetHandler.java:264)
at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleResultSet(DefaultResultSetHandler.java:236)
at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleResultSets(DefaultResultSetHandler.java:150)
at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:60)
at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:73)
at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:60)
at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:267)
at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:137)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:96)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:77)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:108)
... 7 more错误理解：这里Mapped Statements collection does not contain value for org.fkit.mapper.ArticleMapper.selectArticleByOrderId，说的意思是映射集合中找不到org.fkit.mapper.ArticleMapper.selectArticleByOrderId，一般这个情况下，首先看在mybatis-config.xml中是否配置了关于ArticleMapper的映射，一检查，果然没有配置。
这是解决了，解决前我也走了不少弯路，不过在这里也简单的总结下我解决问题的步骤：

1.确定xml文件中<mapper namespace=""/>中的namespace是否路径正确(在此案例中namespace与实际路径一致)，由于namespace不同会引发此问题
2.确定xml文件的名称是否与接口类的名称保持一致，有时候出现这个问题，如abcd.xml,接口类确实abce.java，一字之差导致异常的发生。
3.确实mybatis-config.xml中是否配置了关于该xml文件的映射