这不是来自SQL查询语句，而是来自Connection语句。当我收到此错误时，我正在尝试连接到MySQL数据库。
我搜索过但没有找到解决问题的答案。我正在尝试建立与MySQL的连接并继续收到此错误; java.math.BigInteger无法强制转换为java.lang.Long。
堆栈跟踪是：
java.sql.SQLException: java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Long
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:988)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:974)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.ConnectionImpl.buildCollationMapping(ConnectionImpl.java:1041)
at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3481)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2445)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2215)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:813)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:334)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.healthplan.ocGroupsDAO.getGroup(ocGroupsDAO.java:37)
at com.healthplan.ocInitialize.doGet(ocInitialize.java:36)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:728)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:591)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:527)
at org.apache.taglibs.standard.tag.common.core.ImportSupport.acquireString(ImportSupport.java:314)
at org.apache.taglibs.standard.tag.common.core.ImportSupport.doEndTag(ImportSupport.java:171)
at org.apache.jsp.index_jsp._jspx_meth_c_005fimport_005f0(index_jsp.java:282)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:173)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:443)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:728)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:470)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:395)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:316)
at com.healthplan.ocLogin.doGet(ocLogin.java:84)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1468)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Long
at com.mysql.jdbc.ConnectionImpl.buildCollationMapping(ConnectionImpl.java:992)
... 67 more
我的代码是：
public class ocGroupsDAO extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
public List<group> getGroup(HttpServletRequest request) {
ArrayList<group> groups = new ArrayList<group>();
// JDBC driver name and database
Properties props =
(Properties)request.getServletContext().getAttribute("props");
Properties sqlStmts =
(Properties)request.getServletContext().getAttribute("sqlStmts");
String DB_URL = props.getProperty("jdbcName") + "//" +
props.getProperty("sqlServer") + "/" + props.getProperty("database");
// Database credentials
final String USER = props.getProperty("sqlUserID");
final String PASS = props.getProperty("sqlUserPassword");
try {
// Register JDBC driver
String driver = props.getProperty("driver");
Class.forName(driver);
// Open a connection
Connection conn = DriverManager.getConnection(DB_URL, USER, PASS);
// Execute SQL query
PreparedStatement stmt =
conn.prepareStatement(sqlStmts.getProperty("groupSQL"));
ResultSet rs = stmt.executeQuery();
// Extract data from result set
while(rs.next()){
//Retrieve by column name
group grp = new group();
grp.setGroupID(rs.getInt("grpID"));
grp.setGroupName(rs.getString("grpName"));
groups.add(grp);
}
// Clean-up environment
rs.close();
stmt.close();
conn.close();
} catch(SQLException se) {
//Handle errors for JDBC
se.printStackTrace();
} catch(Exception e) {
//Handle errors for Class.forName
e.printStackTrace();
} //end try
return groups;
}
}
这句话失败了：
Connection conn = DriverManager.getConnection(DB_URL, USER, PASS);
答案 0 :(得分：0)
我通过将MySQL v8.0降级到MySQL v5.7来解决这个问题。一切都连接起来，我可以执行查询而不会出现此错误。