MyBatis參数格式化异常解决方式：MyBatisSystemException:
问题:今天使用MyBatis开发查询功能时，前台传入查询条件明明是String类型，到后台就报错，提示格式化数值错误，我在传入的參数对象中定义的字段类型是String。在mybaits的xml配置文件里指定的格式是CHAR。可还是报错，參数在mybaits的xml文件里会进行test推断，然后拼接SQL语句。下面是异常内容：
八月 17, 2015 6:05:17 下午 org.apache.catalina.core.StandardWrapperValve invoke 严重: Servlet.service() for servlet [spring] in context with path [/xxx] threw exception [Request processing failed; nested exception is org.mybatis.sp ring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: ### Error querying database. Cause: java.lang.NumberFormatException: For input string: "a" ### Cause: java.lang.NumberFormatException: For input string: "a"] with root cause java.lang.NumberFormatException: For input string: "a" at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1241) at java.lang.Double.parseDouble(Double.java:540) at org.apache.ibatis.ognl.OgnlOps.doubleValue(OgnlOps.java:259) at org.apache.ibatis.ognl.OgnlOps.compareWithConversion(OgnlOps.java:143) at org.apache.ibatis.ognl.OgnlOps.isEqual(OgnlOps.java:186) at org.apache.ibatis.ognl.OgnlOps.equal(OgnlOps.java:578) at org.apache.ibatis.ognl.ASTNotEq.getValueBody(ASTNotEq.java:51) 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.ASTAnd.getValueBody(ASTAnd.java:56) 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:310) at org.apache.ibatis.scripting.xmltags.OgnlCache.getValue(OgnlCache.java:45) at org.apache.ibatis.scripting.xmltags.ExpressionEvaluator.evaluateBoolean(ExpressionEvaluator.java:32) at org.apache.ibatis.scripting.xmltags.IfSqlNode.apply(IfSqlNode.java:33) at org.apache.ibatis.scripting.xmltags.MixedSqlNode.apply(MixedSqlNode.java:32) at org.apache.ibatis.scripting.xmltags.IfSqlNode.apply(IfSqlNode.java:34) at org.apache.ibatis.scripting.xmltags.MixedSqlNode.apply(MixedSqlNode.java:32) at org.apache.ibatis.scripting.xmltags.DynamicSqlSource.getBoundSql(DynamicSqlSource.java:40) at org.apache.ibatis.mapping.MappedStatement.getBoundSql(MappedStatement.java:278) at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:75) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:108) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:102) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:66) 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.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:358) at com.sun.proxy.$Proxy15.selectOne(Unknown Source) at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:163) at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:68) at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:52) at com.sun.proxy.$Proxy17.getUserListTotal(Unknown Source) at com.xxx.xxx.service.impl.UserServiceImpl.getUserListTotal(UserServiceImpl.java:98) at com.xxx.xxx.service.impl.UserServiceImpl$$FastClassByCGLIB$$3c20f566.invoke(<generated>) at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:713) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98) at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:646) at com.xxx.xxx.service.impl.UserServiceImpl$$EnhancerByCGLIB$$df14dfa7.getUserListTotal(<generated>) at com.xxx.xxx.controller.UserController.list(UserController.java:59) 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.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:214) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:748) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:931) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:833) at javax.servlet.http.HttpServlet.service(HttpServlet.java:650) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61) at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108) at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137) at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66) at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108) at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137) at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66) at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449) at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365) at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90) at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83) at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383) at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362) at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:957) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2476) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2465) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)
异常排查：
百度之后也没找到答案，在openflow上也没有找到答案，仅仅有自己排查。既然是类型转换异常。那么就依据指定的代码去查询，发现异常出如今service层，因为service层没有catch异常。且传输的是对象。对象类型肯定是没有问题的，那么问题应该是在mybaits中。mybaits仅仅有xml中有配置这些问题，排查xml，发现下面内容
<if test="user.name != null and user.name != -1 and user.name != ''">
and name = #{user.name,jdbcType=CHAR}
</if>
user.name ！
= -1 这个会不会有问题呢。加个单引號改成user.name != ‘-1’ 试试，结果问题解决。
问题原因：
mybaits的xml配置文件里，test推断时。会自己主动依据要比較參数的类型进行格式化，假设不注意。就会出现格式化错误。