我正在使用Tomcat 6和Postgresql 8.4。我的代码如下所示：

try {
  // Prepared statement inserting something...
} catch (final PSQLException e) {
  LOG.log(Level.SEVERE, "Saving failed.", e);
} catch (final SQLException e) {
  LOG.log(Level.SEVERE, "Saving failed (SQL).", e);
}

这种插入DB可能会导致PSQLException（例如，唯一键冲突），我想用first捕获catch。但是，我实际上在日志中找到的是：

SEVERE: Saving failed (SQL).
org.postgresql.util.PSQLException: ERROR: duplicate key value violates unique constraint "UZIVATELIA_U_LOGIN"
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2102)
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1835)
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:500)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:388)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:273)
    at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:96)
    at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:96)
    at cz.ecoremedia.realpad.web.backend.Users.saveNewUser(Users.java:119)
    at cz.ecoremedia.realpad.web.backend.Users.saveUser(Users.java:237)
    at org.apache.jsp.User_jsp._jspService(User_jsp.java:159)
    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:388)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    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:102)
    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:859)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    at java.lang.Thread.run(Thread.java:662)

如果我检查e捕获的类型，例如：

} catch (final SQLException e) {
  LOG.log(Level.SEVERE, e.getClass().getName());
  LOG.log(Level.SEVERE, "Saving failed (SQL).", e);

它仍然告诉我那是org.postgresql.util.PSQLException。

当我在Eclipse中本地尝试时，它可以PSQLException正常工作- 在第一个catch块中被正确捕获。

如果我正确理解问题，那么org.postgresql.util.PSQLException我所捕获的类与org.postgresql.util.PSQLException实际抛出的类不同。这怎么可能？我究竟做错了什么？

感谢您的想法。