Spring+MyBatis 错误：org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.b

   今天用SSM框架做一个项目的时候，在进行简单的测试，发现一个错误，而这个坑在我毕设的时候遇到一次忘记了，这回要记下来。

   

org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.binding.BindingException: Parameter 'groupName' not
found. Available parameters are [0, 1, param1, param2]

	at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:79)
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:447)
	at com.sun.proxy.$Proxy19.update(Unknown Source)
	at org.mybatis.spring.SqlSessionTemplate.update(SqlSessionTemplate.java:295)
	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:62)
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:53)
	at com.sun.proxy.$Proxy20.updateByPrimaryKey(Unknown Source)
	at com.user.group.service.GroupService.updateByPrimaryKey(GroupService.java:38)
	at TestOne.selectUsersInGroup(TestOne.java:54)
	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:497)
	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.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
	at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
	at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:252)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
	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$2.evaluate(ParentRunner.java:268)
	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:117)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:42)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:262)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:84)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: org.apache.ibatis.binding.BindingException: Parameter 'groupName' not found. Available parameters are [0, 1, param1, param2]
	at org.apache.ibatis.binding.MapperMethod$ParamMap.get(MapperMethod.java:195)
	at org.apache.ibatis.reflection.wrapper.MapWrapper.get(MapWrapper.java:45)
	at org.apache.ibatis.reflection.MetaObject.getValue(MetaObject.java:122)
	at org.apache.ibatis.scripting.defaults.DefaultParameterHandler.setParameters(DefaultParameterHandler.java:79)
	at org.apache.ibatis.executor.statement.PreparedStatementHandler.parameterize(PreparedStatementHandler.java:93)
	at org.apache.ibatis.executor.statement.RoutingStatementHandler.parameterize(RoutingStatementHandler.java:64)
	at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:86)
	at org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:49)
	at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:117)
	at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:76)
	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:497)
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:63)
	at com.sun.proxy.$Proxy26.update(Unknown Source)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:198)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:434)
	... 40 more

 

void updateByPrimaryKey( String groupId, String groupName);

经测试应该是忘了使用@Param。当只有一个参数时，Mapper中可以不使用，应该使用如下：

void updateByPrimaryKey(@Param("groupId") String groupId,@Param("groupName") String groupName);

这样就可以解决了。

原理：

mybatis首先会根据 MapperMethod.java 经过下面方法来转换参数：

public Object convertArgsToSqlCommandParam(Object[] args) {
  final int paramCount = params.size();
  if (args == null || paramCount == 0) {
    return null;
  } else if (!hasNamedParameters && paramCount == 1) {
    return args[params.keySet().iterator().next()];
  } else {
    final Map param = new ParamMap