Java異常未捕獲，代碼繼續執行

Question

我有一個RESTful Web服務，遇到了捕獲異常的問題。 我有一個使用JDBC連接到數據庫的父類。 連接的創建將引發以下異常：

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Client does not support authentication protocol requested by server; consider upgrading MySQL client

沒關系 我知道是什么原因造成的，稍后我會修復它。 問題是它被以下代碼捕獲：

protected Connection connection;

protected void openConnection() throws SQLException {
    try {
        Class.forName(dbProperties.getDriver());
        connection = DriverManager.getConnection(dbProperties.getConnectionString());
    } catch (Exception e) {
        LOGGER.log(Level.SEVERE, "Caught SQLException", e);
        throw new SQLException();
    }
 }

根據我的判斷，它顯然捕獲了異常並引發了SQLException。 但是，兒童班沒有抓住它。 碼：

try {
    openConnection();
    String sql = "...";
    PreparedStatement statement = connection.prepareStatement(sql);
    ...
} catch (SQLException e) {
    LOGGER.log(Level.SEVERE, "Caught SQLException", e);
    throw new DatabaseException("Database Exception!", e);
}

代碼繼續到PreparedStatement部分，該部分提供了NullPointer，因為連接為空。

這導致我的服務沒有返回適當的數據庫錯誤消息，而是返回了其中包含stacktrace的未經檢查的響應。 我絕對不想要的。

我在這里做錯了什么？ 為什么未引發或捕獲SQLException，從而導致應按應有的方式引發DatabaseException？

---

日志記錄的輸出是這樣的：

openConnection Caught SQLException
 com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Client does not support authentication protocol requested by server; consider upgrading MySQL client
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
    at com.mysql.jdbc.Util.getInstance(Util.java:381)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:984)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3491)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3423)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:910)
    at com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:3923)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1273)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2031)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:718)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
    at java.sql.DriverManager.getConnection(DriverManager.java:664)
    at java.sql.DriverManager.getConnection(DriverManager.java:270)
    at dao.AbstractDao.openConnection(AbstractDao.java:22)
    at dao.UserDao.getUser(UserDao.java:16)
    at rest.LoginService.doLogin(LoginService.java:35)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.openejb.server.cxf.rs.PojoInvoker.performInvocation(PojoInvoker.java:43)
    at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:96)
    at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:189)
    at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:99)
    at org.apache.openejb.server.cxf.rs.AutoJAXRSInvoker.invoke(AutoJAXRSInvoker.java:68)
    at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:59)
    at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:96)
    at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:308)
    at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
    at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:252)
    at org.apache.openejb.server.cxf.rs.CxfRsHttpListener.doInvoke(CxfRsHttpListener.java:251)
    at org.apache.tomee.webservices.CXFJAXRSFilter.doFilter(CXFJAXRSFilter.java:94)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
    at org.apache.openejb.server.httpd.EEFilter.doFilter(EEFilter.java:65)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108)
    at org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:44)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.tomee.catalina.OpenEJBSecurityListener$RequestCapturer.invoke(OpenEJBSecurityListener.java:97)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:784)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:802)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1410)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)

Answer 1

您顯示的代碼似乎沒有錯。 您確定NullPointerException恰好在您聲明的位置拋出了嗎？ 捕獲Stacktrace並共享。