Wex5执行Class[search.login__do] Method[login]失败

====================开发工具版本：WeX5_V3.3========================

报错背景：大二的时候用这个工具开发了一款APP，备份了项目数据库的SQL文件+项目在WeX5_V3.3\model\UI2下的GK（存放页面）和WeX5_V3.3\model\Baas里的search（存放服务源代码）这两个文件夹后，由于不再用WeX5开发就把平台删掉了。后来毕设重新需要运行这个项目，就

　　1.重新在WeX5官网下载了WeX5_V3.3版本并解压；

　　2.把GK文件夹拷贝至WeX5_V3.3\model\UI2目录下，把search拷贝至WeX5_V3.3\model\Baas目录下；

　　3.启动自带数据库，启动数据库管理工具，直接执行备份的项目数据库SQL文件，建库成功。启动开发工具；

　　4.右键GK下的index.w文件，选择“在浏览器中运行”

　　5.发现访问数据库的操作时Tomcat报错，好像baas里我写的访问数据库的java类都没有找到似的。

由于报错时没有及时截图，问题解决后才想到要整理这次的解决思路，故重新搜索了一个相似问题的报错代码。我的报错类似于如下：

com.justep.baas.action.ActionException: 执行Class[device.Deploy__do] Method[queryDeploy]失败

        at com.justep.baas.action.Engine.execAction(Unknown Source)

        at com.justep.baas.action.Engine.execAction(Unknown Source)

        at com.justep.baas.servlet.BaasServlet.execService(Unknown Source)

        at com.justep.baas.servlet.BaasServlet.service(Unknown Source)

        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)

        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)

        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)

        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)

        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)

        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:861)

        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:606)

        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)

        at java.lang.Thread.run(Thread.java:745)

Caused by: java.lang.reflect.InvocationTargetException

        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)

        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

        at java.lang.reflect.Method.invoke(Method.java:606)

        ... 16 more

Caused by: org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create
PoolableConnectionFactory (Unknown system variable 'language')

        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1549)

        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1388)

        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)

        at com.justep.baas.data.DataUtils.getConnection(Unknown Source)

        at com.justep.baas.action.ActionContext.getConnection(Unknown Source)

        at com.justep.baas.action.CRUD.query(Unknown Source)

        at device.Deploy__do.queryDeploy(Deploy__do.java:43)

        ... 20 more

Caused by: java.sql.SQLException: Unknown system variable 'language'

        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:998)

        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3847)

        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3783)

        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2447)

        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2594)

        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2541)

        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2499)

        at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1432)

        at com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:3870)

        at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3284)

        at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2293)

        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2079)

        at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794)

        at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)

        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)

        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

        at java.lang.reflect.Constructor.newInstance(Constructor.java:526)

        at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)

        at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)

        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)

        at org.apache.tomcat.dbcp.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)

        at org.apache.tomcat.dbcp.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:582)

        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.validateConnectionFactory(BasicDataSource.java:1556)

        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1545)

        ... 26 more

三月 30, 2016 4:32:47 下午 org.apache.catalina.core.StandardWrapperValve invoke

严重: Servlet.service() for servlet WeX5_Baas_Servlet threw exception

java.sql.SQLException: Unknown system variable 'language'

        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:998)

        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3847)

        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3783)

        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2447)

        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2594)

        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2541)

        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2499)

        at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1432)

        at com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:3870)

        at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3284)

        at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2293)

        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2079)

        at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794)

        at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)

        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)

        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

        at java.lang.reflect.Constructor.newInstance(Constructor.java:526)

        at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)

        at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)

        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)

        at org.apache.tomcat.dbcp.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)

        at org.apache.tomcat.dbcp.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:582)

        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.validateConnectionFactory(BasicDataSource.java:1556)

        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1545)

        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1388)

        at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)

        at com.justep.baas.data.DataUtils.getConnection(Unknown Source)

        at com.justep.baas.action.ActionContext.getConnection(Unknown Source)

        at com.justep.baas.action.CRUD.query(Unknown Source)

        at device.Deploy__do.queryDeploy(Deploy__do.java:43)

        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)

        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

        at java.lang.reflect.Method.invoke(Method.java:606)

        at com.justep.baas.action.Engine.execAction(Unknown Source)

        at com.justep.baas.action.Engine.execAction(Unknown Source)

        at com.justep.baas.servlet.BaasServlet.execService(Unknown Source)

        at com.justep.baas.servlet.BaasServlet.service(Unknown Source)

        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)

        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)

        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)

        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)

        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)

        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:861)

        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:606)

        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)

        at java.lang.Thread.run(Thread.java:745)

------------------------------解决思路------------------------

首先我觉得有必要看下平台自带的demo运行时是否能够访问数据库，于是我运行了takeout外卖案例，发现也报错，数据同样访问不到。所以这个很可能是普遍配置出了问题。

1.找到官网“WeX5后端服务教程”视频教程，发现我还少了在开发工具中配置数据源：

（1）窗口->首选项->studio配置->数据源->增加；然后填写数据库的链接信息。我用的端口不是默认的3306而是自己设置的3308（因为我原本装有MySQL所以把Wex5自带的MySQL端口改了）

（2）打开Baas下的db.config.m文件，把自己的search数据库点勾上。

2.上面配置了数据源后，仍然报错。于是我参考搜到的Wex5论坛帖子（这一步太有用了）

（1）http://bbs.wex5.com/forum.php?mod=viewthread&tid=89538&highlight=%E6%89%A7%E8%A1%8CClass%2BMethod%2B%E5%A4%B1%E8%B4%A5

这个人说他解决了，原因是mysql的jar包版本太高，降到mysql-connector-java-5.1.22-bin.jar就好了。

（2）http://bbs.wex5.com/forum.php?mod=viewthread&tid=86472&highlight=%E6%89%A7%E8%A1%8CClass%2BMethod%2B%E5%A4%B1%E8%B4%A5

里面有个人提到了他的几种尝试：

3.参考过后，我是这么做的：（多亏了参考帖子，我解决了问题）

（1）找到WeX5_V3.3\apache-tomcat\conf\context.xml，发现数据源配置已经写好了：如下图。于是我没有改动。

（2）从网上下载了mysql-connector-java-5.1.22-bin.jar，找到WeX5_V3.3\apache-tomcat\lib目录下，发现原来自带的jar包版本是mysql-connector-java-5.1.36-bin.jar，于是我把原来的5.1.36删掉，把我刚下载的5.1.22拷贝到此目录下。

（3）重新打开数据库服务、开发工具，把baas、UI2两个目录单击右键“模块编译”，完成后，启动tomcat，重新在浏览器中运行，不论是我的项目还是demo项目，都可以访问到数据库中的记录了。

问题解决。

猜想核心起作用的一步，就是替换了数据库连接驱动的版本，也就是那个jar包。