org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'name' in 'class java.lang.String'

发表于

今天使用mybatis进行如下查询时一直报错:

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select * from people where name like concat('%','${name}','%')

异常:

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org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'name' in 'class java.lang.String'
	at org.apache.ibatis.reflection.Reflector.getGetInvoker(Reflector.java:381)
	at org.apache.ibatis.reflection.MetaClass.getGetInvoker(MetaClass.java:164)
	at org.apache.ibatis.reflection.wrapper.BeanWrapper.getBeanProperty(BeanWrapper.java:162)
	at org.apache.ibatis.reflection.wrapper.BeanWrapper.get(BeanWrapper.java:49)
	at org.apache.ibatis.reflection.MetaObject.getValue(MetaObject.java:122)
	at org.apache.ibatis.scripting.xmltags.DynamicContext$ContextMap.get(DynamicContext.java:94)
	at org.apache.ibatis.scripting.xmltags.DynamicContext$ContextAccessor.getProperty(DynamicContext.java:108)
	at org.apache.ibatis.ognl.OgnlRuntime.getProperty(OgnlRuntime.java:2420)
	at org.apache.ibatis.ognl.ASTProperty.getValueBody(ASTProperty.java:114)
	at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212)
	at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:258)
	at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:494)

查了相关博客,终于解决了:

对上面的异常，网上说问题原因是Mybatis默认采用OGNL解析参数(ps:还不懂,得恶补)，所以会自动采用对象树的形式获取传入的变量值，解决方法有两个：

  1. 将参数名（上面的例子为’name’）替换为”_parameter” ，即：

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    select * from people where name like concat('%','${_parameter}','%')

  2. 在接口中定义方法时 增加“@Param(“参数名”)” 标记 如:

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    public List<People> findSomePeople(@Param("name") String name);
github大神相关问题的回答:
  • As documented, parameterType is optional and it is usually better to let MyBatis detect it.
  • As your statement has one simple type parameter without @Param annotation, you need to use the implicit name _parameter to reference it in the OGNL expression or ${}.
  • Java does not allow us to obtain the parameter name at runtime, unfortunately.Please search ‘java parameter name’ for more detailed explanation.

So, as I explained, you may have to
1) modify the xml mapper as follows:

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<when test="_parameter &lt; 0">
  id = 0-#{id}
</when>

Or 2) add @Param(“id”) to the method parameter.

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User findById(@Param("id")int id);