我有一个Java类，它通过JDBC访问MySQL数据库，我在Tomcat上运行的JSP中使用它，我得到No Driver Found Exception。
我有一个方法：
private static Statement makeStatement() {
try{
com.mysql.jdbc.Driver d = null;
try{d = new com.mysql.jdbc.Driver();}catch(Exception e){
System.out.println("ERROR BY NEW DRIVER " + e.toString() +
"\n");e.printStackTrace();}
Connection con = DriverManager.getConnection(url, user, password);
return con.createStatement();
}catch(java.sql.SQLException ex){
System.out.println("ERROR IN makeStatement " + "\nERROR - " +
ex.toString() + "\n ERROR CODE:\n " + ex.getErrorCode() +
"\nSQLSTATE:\n " + ex.getSQLStat e());ex.printStackTrace();}
return null;
}
在Connection con = DriverManager.getConnection(url, user, password);引发错误。这是我的catalina.out打印输出：
Received Parameters
ERROR IN makeStatement
ERROR - java.sql.SQLException: No suitable driver found for
ERROR CODE:
0
SQLSTATE:
08001
java.sql.SQLException: No suitable driver found for
at java.sql.DriverManager.getConnection(DriverManager.java:602)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at message.Message.makeStatement(Message.java:72)
at message.Message.query(Message.java:79)
at message.Message.getName(Message.java:225)
at org.apache.jsp.message_jsp._jspService(message_jsp.java:288)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:548)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
at java.lang.Thread.run(Thread.java:619)
ERROR IN QUERY java.lang.NullPointerException
ERROR in getName java.lang.NullPointerException
-----------------------------------
Received Parameters
newMessage =
newpassword =
verifypassword =
sendinfo =
username = Eli
newusername =
login = login
password = tree
ERROR IN makeStatement
ERROR - java.sql.SQLException: No suitable driver found for
ERROR CODE:
0
SQLSTATE:
08001
java.sql.SQLException: No suitable driver found for
at java.sql.DriverManager.getConnection(DriverManager.java:602)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at message.Message.makeStatement(Message.java:72)
at message.Message.query(Message.java:79)
at message.Message.validUser(Message.java:195)
at org.apache.jsp.message_jsp._jspService(message_jsp.java:123)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:548)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
at java.lang.Thread.run(Thread.java:619)
ERROR IN QUERY java.lang.NullPointerException
ERROR in validUser java.lang.NullPointerException
ERROR IN makeStatement
ERROR - java.sql.SQLException: No suitable driver found for
ERROR CODE:
0
SQLSTATE:
08001
java.sql.SQLException: No suitable driver found for
at java.sql.DriverManager.getConnection(DriverManager.java:602)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at message.Message.makeStatement(Message.java:72)
at message.Message.query(Message.java:79)
at message.Message.getName(Message.java:225)
at org.apache.jsp.message_jsp._jspService(message_jsp.java:288)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:548)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
at java.lang.Thread.run(Thread.java:619)
ERROR IN QUERY java.lang.NullPointerException
ERROR in getName java.lang.NullPointerException
唯一重要的错误是makeStatement()中的错误，因为失败会导致所有其他错误。我有四重检查我的WEB-INF / lib目录中有正确的jar文件，并且我已经重新启动Tomcat的次数超过了我想要的次数。我有一个单独的webapp，它在另一个.java文件中使用makeStatement()，并且该webapp运行正常。甚至更奇怪的是我在.java中有这个：
static {
System.err.println("\n\nTEST MYSQL ACCESS: dump all relevant tables:");
dump();
System.err.println("END OF MYSQL ACCESS ACCESS.");
}
public static void dump() {
try {
readUsers();
for (UserRecord u: users)
System.err.println(u.username+" "+u.password);
} catch (Exception e) {System.err.println(e);}
}
其中readUsers()使用makeStatement()从数据库中读取所有用户。这实际上是有效的，数据库中的所有用户都打印出来（这里没有显示出于显而易见的原因:)）然后发现驱动程序未找到错误。
答案 0 :(得分：13)
java.sql.SQLException：找不到合适的驱动程序
此异常可能有两个原因：
由于驱动程序似乎被加载（虽然方式不正确），看起来URL显然是错误的。确保url变量的值与以下格式匹配
jdbc:mysql://localhost:3306/dbname
无关具体问题：Java代码不属于JSP文件。也是如此。您的异常处理也很糟糕，您应该抛出异常（以便阻止执行代码的残余），而不是打印消息/跟踪，然后继续代码。
答案 1 :(得分：2)
您是否使用驱动程序注册了课程？例如：
Class.forName("net.sourceforge.jtds.jdbc.Driver");
DriverManager.getConnection(url,user,password);
答案 2 :(得分：2)
我不得不从WEB-INF / lib 删除 mysql-connector-java - * .jar并将添加添加到tomcat6 / lib文件夹中。 （tomcat6是安装tomcat的地方。）我不知道为什么会这样，但它对我有用。
答案 3 :(得分：1)
您是否将空的url字符串传递给getConnection（）？错误消息开始
No suitable driver found for ERROR
[空白]找不到合适的驱动程序？好像你没有在这里传递网址。
答案 4 :(得分：-2)
转到项目的库文件夹并右键单击它，然后转到“添加库”选项。现在添加mysql.jdbc.Driver