mybatis+idea读取mysql中数据库出现读取出来非数据的情况

最新推荐文章于 2023-04-28 17:37:21 发布

原创最新推荐文章于 2023-04-28 17:37:21 发布 · 246 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#java #idea #mybatis #mysql

本文讲述了在Mybatis项目中忘记重写toString()方法导致的错误输出，以及如何修复，最终展示了正确的测试结果，包括用户对象而非数据库连接。

太蠢了太蠢了，这个东西以前学过，可是忘了

忘了重写toString()方法

导致出现以下问题：

忘了重写toString()方法读取出来的结果：

读取出来的是数据库连接对象：

"C:\Program Files\Java\jdk1.8.0_271\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\IntelliJ IDEA 2020.3.1\lib\idea_rt.jar=49878:D:\IntelliJ IDEA 2020.3.1\bin" -Dfile.encoding=UTF-8 -classpath "D:\IntelliJ IDEA 2020.3.1\lib\idea_rt.jar;D:\IntelliJ IDEA 2020.3.1\plugins\junit\lib\junit5-rt.jar;D:\IntelliJ IDEA 2020.3.1\plugins\junit\lib\junit-rt.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\rt.jar;C:\Users\lenovo\IdeaProjects\javaweb-01-maven\javaweb-session-cookie\day02_eesy_01mybatisCRUD\target\test-classes;C:\Users\lenovo\IdeaProjects\javaweb-01-maven\javaweb-session-cookie\day02_eesy_01mybatisCRUD\target\classes;D:\apache-maven-3.8.1\maven-repo\org\mybatis\mybatis\3.4.5\mybatis-3.4.5.jar;D:\apache-maven-3.8.1\maven-repo\mysql\mysql-connector-java\5.1.6\mysql-connector-java-5.1.6.jar;D:\apache-maven-3.8.1\maven-repo\log4j\log4j\1.2.12\log4j-1.2.12.jar;D:\apache-maven-3.8.1\maven-repo\junit\junit\4.11\junit-4.11.jar;D:\apache-maven-3.8.1\maven-repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 com.itheima.test.MybatisTest,testFindAll
2021-05-08 19:55:47,182 0      [           main] DEBUG ache.ibatis.logging.LogFactory  - Logging initialized using 'class org.apache.ibatis.logging.log4j.Log4jImpl' adapter.
2021-05-08 19:55:47,265 83     [           main] DEBUG source.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
2021-05-08 19:55:47,265 83     [           main] DEBUG source.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
2021-05-08 19:55:47,265 83     [           main] DEBUG source.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
2021-05-08 19:55:47,265 83     [           main] DEBUG source.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
2021-05-08 19:55:47,345 163    [           main] DEBUG ansaction.jdbc.JdbcTransaction  - Opening JDBC Connection
2021-05-08 19:55:47,500 318    [           main] DEBUG source.pooled.PooledDataSource  - Created connection 2095490653.
2021-05-08 19:55:47,500 318    [           main] DEBUG ansaction.jdbc.JdbcTransaction  - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@7ce6a65d]
2021-05-08 19:55:47,502 320    [           main] DEBUG m.itheima.dao.IUserDao.findAll  - ==>  Preparing: select * from user; 
2021-05-08 19:55:47,519 337    [           main] DEBUG m.itheima.dao.IUserDao.findAll  - ==> Parameters: 
2021-05-08 19:55:47,537 355    [           main] DEBUG m.itheima.dao.IUserDao.findAll  - <==      Total: 6
com.itheima.domain.User@491cc5c9
com.itheima.domain.User@74ad1f1f
com.itheima.domain.User@6a1aab78
com.itheima.domain.User@462d5aee
com.itheima.domain.User@69b0fd6f
com.itheima.domain.User@757942a1
2021-05-08 19:55:47,538 356    [           main] DEBUG ansaction.jdbc.JdbcTransaction  - Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@7ce6a65d]
2021-05-08 19:55:47,538 356    [           main] DEBUG ansaction.jdbc.JdbcTransaction  - Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@7ce6a65d]
2021-05-08 19:55:47,538 356    [           main] DEBUG source.pooled.PooledDataSource  - Returned connection 2095490653 to pool.

Process finished with exit code 0

重写之后

"C:\Program Files\Java\jdk1.8.0_271\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\IntelliJ IDEA 2020.3.1\lib\idea_rt.jar=49930:D:\IntelliJ IDEA 2020.3.1\bin" -Dfile.encoding=UTF-8 -classpath "D:\IntelliJ IDEA 2020.3.1\lib\idea_rt.jar;D:\IntelliJ IDEA 2020.3.1\plugins\junit\lib\junit5-rt.jar;D:\IntelliJ IDEA 2020.3.1\plugins\junit\lib\junit-rt.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\rt.jar;C:\Users\lenovo\IdeaProjects\javaweb-01-maven\javaweb-session-cookie\day02_eesy_01mybatisCRUD\target\test-classes;C:\Users\lenovo\IdeaProjects\javaweb-01-maven\javaweb-session-cookie\day02_eesy_01mybatisCRUD\target\classes;D:\apache-maven-3.8.1\maven-repo\org\mybatis\mybatis\3.4.5\mybatis-3.4.5.jar;D:\apache-maven-3.8.1\maven-repo\mysql\mysql-connector-java\5.1.6\mysql-connector-java-5.1.6.jar;D:\apache-maven-3.8.1\maven-repo\log4j\log4j\1.2.12\log4j-1.2.12.jar;D:\apache-maven-3.8.1\maven-repo\junit\junit\4.11\junit-4.11.jar;D:\apache-maven-3.8.1\maven-repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 com.itheima.test.MybatisTest,testFindAll
2021-05-08 19:56:11,024 0      [           main] DEBUG ache.ibatis.logging.LogFactory  - Logging initialized using 'class org.apache.ibatis.logging.log4j.Log4jImpl' adapter.
2021-05-08 19:56:11,117 93     [           main] DEBUG source.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
2021-05-08 19:56:11,117 93     [           main] DEBUG source.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
2021-05-08 19:56:11,117 93     [           main] DEBUG source.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
2021-05-08 19:56:11,118 94     [           main] DEBUG source.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
2021-05-08 19:56:11,196 172    [           main] DEBUG ansaction.jdbc.JdbcTransaction  - Opening JDBC Connection
2021-05-08 19:56:11,349 325    [           main] DEBUG source.pooled.PooledDataSource  - Created connection 2095490653.
2021-05-08 19:56:11,349 325    [           main] DEBUG ansaction.jdbc.JdbcTransaction  - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@7ce6a65d]
2021-05-08 19:56:11,351 327    [           main] DEBUG m.itheima.dao.IUserDao.findAll  - ==>  Preparing: select * from user; 
2021-05-08 19:56:11,368 344    [           main] DEBUG m.itheima.dao.IUserDao.findAll  - ==> Parameters: 
2021-05-08 19:56:11,390 366    [           main] DEBUG m.itheima.dao.IUserDao.findAll  - <==      Total: 6
User{id=41, username='老王', address='北京', sex='男', birthday=Tue Feb 27 17:47:08 CST 2018}
User{id=42, username='小二王', address='北京金燕龙', sex='女', birthday=Fri Mar 02 15:09:37 CST 2018}
User{id=43, username='小二王', address='北京金燕龙', sex='女', birthday=Sun Mar 04 11:34:34 CST 2018}
User{id=45, username='传智播客', address='北京金燕龙', sex='男', birthday=Sun Mar 04 12:04:06 CST 2018}
User{id=46, username='老王', address='北京', sex='男', birthday=Wed Mar 07 17:37:26 CST 2018}
User{id=48, username='小马宝莉', address='北京修正', sex='女', birthday=Thu Mar 08 11:44:00 CST 2018}
2021-05-08 19:56:11,393 369    [           main] DEBUG ansaction.jdbc.JdbcTransaction  - Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@7ce6a65d]
2021-05-08 19:56:11,393 369    [           main] DEBUG ansaction.jdbc.JdbcTransaction  - Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@7ce6a65d]
2021-05-08 19:56:11,393 369    [           main] DEBUG source.pooled.PooledDataSource  - Returned connection 2095490653 to pool.

Process finished with exit code 0