查询日期报错问题，invalid comparison: java.util.Date and java.lang.String

早上写了一个接口，按照时间段查询数据库结果的，然后各种错误，一开始写sql查询用的If test，Sql如图所示

<select id="findTrail" resultType="Trail" parameterType="Dog">
		select *
		from trail where 1=1


		<if test="date11 != null and date11 != ''">
			and time&gt;=#{date11}
		</if>
		<if test="date22 != null and date22 != ''">
			and time&lt;=#{date22}
		</if>
		and iot=#{iot} and
		dwfs=#{dwfs}
</select>

然后调用接口进行查询，发现没有传值的时候，date11和date22为空的时候可以查到数据，但是传入日期之后就查不到了，然后报错invalid comparison: java.util.Date and java.lang.String

Exception in thread "main" org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: java.lang.IllegalArgumentException: invalid comparison: java.util.Date and java.lang.String
### Cause: java.lang.IllegalArgumentException: invalid comparison: java.util.Date and java.lang.String
	at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:122)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:113)
	at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:122)
	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:64)
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:53)
	at com.sun.proxy.$Proxy0.selectByCreateTime(Unknown Source)
	at mybatis.Test.buyerInfoTimeTest(Test.java:53)
	at mybatis.Test.main(Test.java:39)
Caused by: java.lang.IllegalArgumentException: invalid comparison: java.util.Date and java.lang.String
	at org.apache.ibatis.ognl.OgnlOps.compareWithConversion(OgnlOps.java:92)
	at org.apache.ibatis.ognl.OgnlOps.isEqual(OgnlOps.java:142)
	at org.apache.ibatis.ognl.OgnlOps.equal(OgnlOps.java:794)
	at org.apache.ibatis.ognl.ASTNotEq.getValueBody(ASTNotEq.java:53)
	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.ASTAnd.getValueBody(ASTAnd.java:61)
	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)
	at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:458)
	at org.apache.ibatis.scripting.xmltags.OgnlCache.getValue(OgnlCache.java:44)
	at org.apache.ibatis.scripting.xmltags.ExpressionEvaluator.evaluateBoolean(ExpressionEvaluator.java:32)
	at org.apache.ibatis.scripting.xmltags.IfSqlNode.apply(IfSqlNode.java:34)
	at org.apache.ibatis.scripting.xmltags.MixedSqlNode.apply(MixedSqlNode.java:33)
	at org.apache.ibatis.scripting.xmltags.TrimSqlNode.apply(TrimSqlNode.java:55)
	at org.apache.ibatis.scripting.xmltags.MixedSqlNode.apply(MixedSqlNode.java:33)
	at org.apache.ibatis.scripting.xmltags.DynamicSqlSource.getBoundSql(DynamicSqlSource.java:41)
	at org.apache.ibatis.mapping.MappedStatement.getBoundSql(MappedStatement.java:280)
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:80)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:120)
	... 7 more

原来这是mybatis中对于时间参数进行比较时的一个bug. 如果拿传入的时间类型参数与空字符串''进行对比判断则会引发异常. 所以在上面的代码中去该该判断, 只保留非空判断就正常了

然后改为

<select id="findTrail" resultType="Trail" parameterType="Dog">
		select *
		from trail where 1=1


		<if test="date11 != null">
			and time&gt;=#{date11}
		</if>
		<if test="date22 != null">
			and time&lt;=#{date22}
		</if>
		and iot=#{iot} and
		dwfs=#{dwfs}
</select>

只是把后面那个“”给去掉了而已，然后就可以访问正常了