JavaWeb项目(JSP+JavaBean+Servlet+Dao+MySQL)中常出现的错误总结:
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错误:NO timezone mapping entry for ‘Gmt 8’ 或:The server time zone
value ‘Öйú±ê׼ʱ¼ä’ is unrecognized or represents more than one
修改:在JDBC连接的URL后面添加:&serverTimezone=UTC
如:jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&ser verTimezone=UTC&useSSL=true
错误:javax.servlet.ServletException:java.sql.SQLException: The server time zone value ‘�й���ʱ��’ is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.
改正:在URL后面部分添加:useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
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错误:No data sources are configured to run this sql 或 No data sources are configured to run this SQL and provide advanced code assistance.
改正:配置MySQL -
问题:cannot resolve method getParameter(Java.lang.String)
改正:添加tomcat
左上角点击“File”----->Project Structure;
新出现对话框点击“Modules”---->“+”---->“Library 或 Module Dependency…”;
弹出对话框,选择tomcat----->点击“Add Selected” ;
点击“Apply”---->“OK”。
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错误:Cannot resolve symbol ‘servlet’
改正:项目->右键、Open Module
Settings->Libraries->右边加号->找到本地Tomcat目录libs下的setvlet-api.jar包,添加其中。 -
错误:Cannot resolve symbol ‘servlet’
改正:项目->右键、Open Module Settings->Libraries->右边加号->找到本地Tomcat目录libs下的setvlet-api.jar包,添加其中。 -
错误:There is no configured/running web-servers found!Please,run any wen-configuration and hit the Refresh button!
改正:在浏览器中打开相应的网址,利用网站地址直接访问。
如:http://localhost:8080/ssm/user/findAllUser.do# -
错误:Can’t connect to MySQL server on ‘localhost’(0)
改正:利用可视化工具(如Navicat、SQLyog)直接创建MySQL的连接有时会报错,原因是电脑中未打开MySQL。需要在cmd下以管理员的命令打开,先使用mysqld -install mysql命令进行初始化,在使用net start mysql启动MySQL服务。