解决org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.xyfer.dao.UserDao.findById

　　在使用Spring整合MyBatis的时候遇到控制台报错：org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.xyfer.dao.UserDao.findById

　　详细信息如下：

org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.xyfer.dao.UserDao.findById

    at org.apache.ibatis.binding.MapperMethod$SqlCommand.<init>(MapperMethod.java:225)
    at org.apache.ibatis.binding.MapperMethod.<init>(MapperMethod.java:48)
    at org.apache.ibatis.binding.MapperProxy.cachedMapperMethod(MapperProxy.java:65)
    at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:58)
    at com.sun.proxy.$Proxy12.findById(Unknown Source)
    at UserDaoTest.test(UserDaoTest.java:17)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

　　这个问题总结如下：

1、仔细检查mapper.xml中的namesapce是否为dao层相应接口的全类名；

2、仔细检查mapper.xml中sql语句的id和dao层相应接口中的方法名称是否一致，包括参数类型、parameterType、resultType、resultMap是够一致；

3、application.xml中或者mybatis.xml中配置mapper文件的路径和映射接口类的包名是否正确：