org.apache.ibatis.exceptions.PersistenceException:
### Error querying database. Cause: org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'empid' in 'class cn.happy.entity.Emp'
### Cause: org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'empid' in 'class cn.happy.entity.Emp'
at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:23)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:107)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:98)
at cn.happy.test.Test5_MyBatisDynamic.test_getAllEmpInfo(Test5_MyBatisDynamic.java:36)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
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.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'empid' in 'class cn.happy.entity.Emp'
at org.apache.ibatis.reflection.Reflector.getGetInvoker(Reflector.java:377)
at org.apache.ibatis.reflection.MetaClass.getGetInvoker(MetaClass.java:167)
at org.apache.ibatis.reflection.wrapper.BeanWrapper.getBeanProperty(BeanWrapper.java:149)
at org.apache.ibatis.reflection.wrapper.BeanWrapper.get(BeanWrapper.java:45)
at org.apache.ibatis.reflection.MetaObject.getValue(MetaObject.java:113)
at org.apache.ibatis.scripting.xmltags.DynamicContext$ContextMap.get(DynamicContext.java:89)
at org.apache.ibatis.scripting.xmltags.DynamicContext$ContextAccessor.getProperty(DynamicContext.java:107)
at org.apache.ibatis.ognl.OgnlRuntime.getProperty(OgnlRuntime.java:1657)
at org.apache.ibatis.ognl.ASTProperty.getValueBody(ASTProperty.java:92)
at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:170)
at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:210)
at org.apache.ibatis.ognl.ASTNotEq.getValueBody(ASTNotEq.java:49)
at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:170)
at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:210)
at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:333)
at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:413)
at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:395)
at org.apache.ibatis.scripting.xmltags.OgnlCache.getValue(OgnlCache.java:45)
at org.apache.ibatis.scripting.xmltags.ExpressionEvaluator.evaluateBoolean(ExpressionEvaluator.java:29)
at org.apache.ibatis.scripting.xmltags.IfSqlNode.apply(IfSqlNode.java:30)
at org.apache.ibatis.scripting.xmltags.MixedSqlNode.apply(MixedSqlNode.java:29)
at org.apache.ibatis.scripting.xmltags.DynamicSqlSource.getBoundSql(DynamicSqlSource.java:37)
at org.apache.ibatis.mapping.MappedStatement.getBoundSql(MappedStatement.java:265)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:79)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:104)
... 26 more
这个异常信息在开发的过程中也经常的可以看得到，当然也是比较简单的异常。在异常的信息中比较清楚的指明了引发异常的原因There is no getter for property named 'empid' in 'class cn.happy.entity.Emp'，找到对应的MODEL看看有没有对应的属性和对应的SET和GET 方法！我这里是缺少对应的属性，也根本没有对应的SET和GET方法！
不过需要注意的是：在MyBatis映射文件中用#和$传递参数的特点，#是以占位符的形式来传递对应变量的参数值的，框架会对传入的参数做预编译的动作，用$时会将传入的变量的参数值原样的传递过去，并且用$传递传递参数的时候需要有对应的GET方法，在MyBatis的映射文件中如果用某个变量传递传递参数，这个变量必须存在于对应的模型中，并且有对应的GET方法！此点常常引起莫名的异常问题，要多加注意！
主要原因，其实是实体类的字段大小写和if语句里的字段大小写不一致!