的Tomcat 6和MySQL在Ubuntu

Question

5.x的連接錯誤嘗試連接到在Tomcat 6運行JSP web應用一個MySQL數據庫5.x中，我得到以下異常：

org.apache.jasper.JasperException: javax.servlet.ServletException: com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: 

** BEGIN NESTED EXCEPTION ** 

java.net.SocketException 
MESSAGE: java.security.AccessControlException: access denied (java.net.SocketPermission [0:0:0:0:0:0:0:1]:3307 connect,resolve) 

STACKTRACE: 

java.net.SocketException: java.security.AccessControlException: access denied (java.net.SocketPermission [0:0:0:0:0:0:0:1]:3307 connect,resolve) 
    at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:151) 
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:280) 
    at com.mysql.jdbc.Connection.createNewIO(Connection.java:1699) 
    at com.mysql.jdbc.Connection.<init>(Connection.java:405) 
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:268) 
    at java.sql.DriverManager.getConnection(DriverManager.java:620) 
    at java.sql.DriverManager.getConnection(DriverManager.java:200) 
    at org.apache.jsp.doLogin_jsp._jspService(doLogin_jsp.java:70) 
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) 
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374) 
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342) 
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) 
    at sun.reflect.GeneratedMethodAccessor32.invoke(Unknown Source) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:616) 
    at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:244) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at javax.security.auth.Subject.doAsPrivileged(Subject.java:537) 
    at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:276) 
    at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:162) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:283) 
    at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:56) 
    at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:189) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:185) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286) 
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852) 
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) 
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) 
    at java.lang.Thread.run(Thread.java:636) 

有什麼事情是原因，我該如何解決它？

Answer 1

這裏是跟蹤的相關位：

java.net.SocketException異常消息：java.security.AccessControlException：訪問被拒絕（java.net.SocketPermission [0：0：0：0：0 ：0：0：1]：3307連接，解析）

該webapp沒有連接/解析提及的套接字的權限。您需要在Tomcat級別配置它。打開/conf/catalina.policy並添加以下代碼塊：如果你想更嚴格一點，例如

grant { 
    permission java.net.SocketPermission "localhost:3307", "connect,resolve"; 
}; 

授予訪問只有特定的JDBC驅動程序，它存在於/lib/filename.jar，然後添加此相反：

grant codeBase "jar:file:${catalina.home}/lib/filename.jar!/-" { 
    permission java.net.SocketPermission "localhost:3307", "connect,resolve"; 
}; 

---

無關的具體問題，下面幾行

at java.sql.DriverManager.getConnection(DriverManager.java:200) 
at org.apache.jsp.doLogin_jsp._jspService(doLogin_jsp.java:70) 

表明您'重新連接JSP文件中的數據庫。也許你只是開始學習，但我只提到這不是最好的做法。數據庫連接應該在它自己的類中完成，然後在一個servlet類中使用它，這個類繼而轉發給JSP，並轉而顯示結果。通過URL調用servlet應該會得到相同的結果，但最終會得到更好的可重用和可維護的代碼。