MyBatis报错 The project was not built due to "Could not delete ''.". Fix the problem, then try ref

一时失言乱红尘 2022-03-31 15:37 227阅读 0赞

## 主要代码 ##

1、MyBatis-config.xml\*

<configuration>
    	<properties resource="database.properties"/> 
    	
    	<properties>
    		<property name="driver" value="com.mysql.jdbc.Driver"/>
    		<property name="url" value="jdbc:mysql://localhost:3306/smbms"/>
    		<property name="username" value="root"/>
    		<property name="password" value="1998"/>
    	</properties>
    	<settings>
    		<setting name="logImpl" value="LOG4J"/>
    	</settings>
    	<typeAliases>
    		
    		<package name="cn.smbms.pojo"/>
    		
    	</typeAliases>
    
    	
    	<environments default="development">
    		<environment id="development">
    		
    			<transactionManager type="JDBC"/>
    			
    			
    			<dataSource type="POOLED">
    				<property name="driver" value="${driver}"/>
    				<property name="url" value="${url}"/>
    				<property name="username" value="${username}"/>
    				<property name="password" value="${password}"/>
    			</dataSource>
    		</environment>
    	</environments>
    
    	
    	<mappers>
    		
    		<mapper resource="cn/smbms/dao/user/UserMapper.xml"></mapper> 
    		<mapper resource="cn/smbms/dao/provider/ProviderMapper.xml"></mapper> 
    		
    		
    	</mappers>

2、UserMapper.xml(实体类User表与sql语句之间的映射)

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzA5NDM2MQ_size_16_color_FFFFFF_t_70]  
3、单元测试代码  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzA5NDM2MQ_size_16_color_FFFFFF_t_70 1]  
以上代码主要做对User用户表的个数进行统计,并输出统计结果,第一次运行报了下面这个错。

*  (0 ms) - 2019-1-3 11:01:57DEBUG Logging initialized using ‘class org.apache.ibatis.logging.log4j.Log4jImpl’ adapter.
 *  (4 ms) - 2019-1-3 11:01:57DEBUG Logging initialized using ‘class org.apache.ibatis.logging.log4j.Log4jImpl’ adapter.
 *  (18 ms) - 2019-1-3 11:01:57DEBUG PooledDataSource forcefully closed/removed all connections.
 *  (18 ms) - 2019-1-3 11:01:57DEBUG PooledDataSource forcefully closed/removed all connections.
 *  (19 ms) - 2019-1-3 11:01:57DEBUG PooledDataSource forcefully closed/removed all connections.
 *  (19 ms) - 2019-1-3 11:01:57DEBUG PooledDataSource forcefully closed/removed all connections.

在进行程序调试后，发现程序在执行到以下这句  
![在这里插入图片描述][20190103184621761.png]  
跳出了try块进入异常处理catch块，所以初步判断是MyBatis-config.xml文件编写有误，在xml文件更改正确后,重新执行方法时,控制台又报出以下错误，并且项目名一直标红色的×角标,但是项目中实际上没有报错的文件。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzA5NDM2MQ_size_16_color_FFFFFF_t_70 2]

## 错误原因 ##

在项目中对java文件或xml文件进行修改后，造成已编译的class文件与现有java文件不匹配，需要重新编译

## 解决方案 ##

右击项目–source–Clean Up—清除项目中已生成的class文件，重新编译，刷新项目,如果问题还是没有得到解决那就重启eclipse或重启电脑就ok了。

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzA5NDM2MQ_size_16_color_FFFFFF_t_70]: /images/20220331/226e730101444f3a98585d276020063c.png
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[20190103184621761.png]: /images/20220331/37bdd0b97d324e2cb6430cacdb7a1985.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzA5NDM2MQ_size_16_color_FFFFFF_t_70 2]: /images/20220331/a880c346a1774070a243aa969fee94e6.png