Mybatis报错: There is no getter for property named xxx
在mapper文件中函数的形参上加上注解.
例如：
出现了如下错误：核心错误提示就是There is no getter for property named xxx
### Error querying database. Cause: org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'id' in 'class java.lang.Integer'
### Cause: org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'id' in 'class java.lang.Integer'
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.$Proxy0.getUserById(Unknown Source)
at cn.laochou.mybatis.UserService.selectUser(UserService.java:25)
at cn.laochou.mybatis.UserService.main(UserService.java:92)
Caused by: org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'id' in 'class java.lang.Integer'
at org.apache.ibatis.reflection.Reflector.getGetInvoker(Reflector.java:380)
at org.apache.ibatis.reflection.MetaClass.getGetInvoker(MetaClass.java:170)
at org.apache.ibatis.reflection.wrapper.BeanWrapper.getBeanProperty(BeanWrapper.java:152)
at org.apache.ibatis.reflection.wrapper.BeanWrapper.get(BeanWrapper.java:48)
at org.apache.ibatis.reflection.MetaObject.getValue(MetaObject.java:116)
at org.apache.ibatis.scripting.xmltags.DynamicContext$ContextMap.get(DynamicContext.java:97)
at org.apache.ibatis.scripting.xmltags.DynamicContext$ContextAccessor.getProperty(DynamicContext.java:116)
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.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:413)
at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:395)
at org.apache.ibatis.scripting.xmltags.OgnlCache.getValue(OgnlCache.java:48)
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.TrimSqlNode.apply(TrimSqlNode.java:54)
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)
... 7 more
上面只是个示例错误，在实际情况中，你仔细看看错误，就能定位到出现错误的mapper文件，然后，检查下相应的函数有没有加 @Param("id")这种注解
例如上面的错误提示，mybatis在查询的时候不知道叫id的是啥，查看mapper文件，可能发现有个id在作为某个函数的形参时，没有@Param注解，加上即可
public User getUserById(@Param("id") String id);
