运行几个小时后，应用程序出现黑屏

Question

我们最近将服务器从 Tomcat 6 升级到 Tomcat 9，并且应用程序每隔几个小时就会出现故障。到目前为止我收集到的一些要点：

系统在本地计算机上无任何错误地加载，这只发生在生产站点上。
应用程序运行了 6-7 小时，然后遇到了这个白屏问题。
重新启动 Tomcat 服务器后，系统会再次恢复几个小时，然后重复整个过程。
它通常会在启动几个小时后出现连接问题，并且当发生这种情况时，数据库中的客户端连接似乎非常高。

这是 Tomcat 中记录的内容。在调试时，用户不为空，所以我不确定真正的问题是什么。我不确定是否需要重做数据库连接，或者这是 Tomcat.

的配置问题

26-Jan-2022 11:23:46.614 SEVERE [https-jsse-nio-443-exec-6] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [jsp] in context with path [] threw exception [An exception occurred processing [jsp/index.jsp] at line [86]

83: <%
84:     AccountInfo accountInfo = new AccountInfo();
85:     String user = testOBJECTS.getName();
86:     accountInfo.init(user);
87:   



Stacktrace:] with root cause
    java.lang.IllegalStateException: Failed to get connection..
        at test.library.TestConnectionFactory.getConnection(Unknown Source)
        at test.model.AccountInfo.init(Unknown Source)
        at org.apache.jsp.jsp.index_jsp._jspService(index_jsp.java:248)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:764)
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:466)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:379)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:327)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:764)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
        at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357)
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1726)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
        at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Unknown Source)

这是 index.jsp 页面中获取用户的代码。

<jsp:useBean id="testOBJECTS" class="test.mainJspBean"/>
<jsp:useBean id="testTop" class="test.loggedInBean"/>
<jsp:useBean id="aircraftFolder" class="test.library.AircraftFolder"/>
<% 
  testOBJECTS.setLogin(request);
    if (testOBJECTS.getLoggedIn()) {
     testTop.setServletTop(request, testOBJECTS.getLoggedIn(), null, testOBJECTS.getName());

    AccountInfo accountInfo = new AccountInfo();
    String user = testOBJECTS.getName();
    accountInfo.init(user);
    
    }
%>

这是设置用户的 MainJspBean.java class。

package test;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;

import org.apache.logging.log4j.Logger; 
import org.apache.logging.log4j.LogManager;

import test.library.SubscribeConnectionFactory;
import test.loginLibraries.Login;

public class mainJspBean
{
    static Logger log = LogManager.getLogger(mainJspBean.class.getName());
    private String clientPage = "";
    private boolean loggedIn = false;
    private String name = "";

    public String getLogin()
    {
        return clientPage;
    }

    public void setLogin(HttpServletRequest request) throws SQLException {
        String user = (String) request.getSession().getAttribute(Login.UID);
        String pass = (String) request.getSession().getAttribute(Login.PASS);
        boolean loggedin = loggedInBean.isLoggedIn(user, pass);
        if (loggedin) {
            this.loggedIn = loggedin;
            name = user;
            System.out.println("name: " + name);
            
            clientPage += "<div align=\"justify\" class=\"style1\"><a href=\"https://" + IPs.WebAddress() + "/jsp/index.jsp\">TEST Online</a></div>\n";
        } else {
            clientPage += "<br><FORM  autocomplete=\"off\" METHOD=\"post\" ACTION=\"https://"+ IPs.WebAddress() +"/test/login\" onSubmit=\"return checkWhiteSpace()\">\n" +
                      "<table border=\"0\" cellpadding=\"0\" cellspacing=\"0\" align=\"right\" valign=\"top\">\n" +
                      "<tr>\n" +
                      "<td nowrap align=\"right\" ><span class=\"topText\" align=\"right\">User Name:&nbsp;</span><input type=\"text\" name=\"uid\" id=\"uid\" size=\"8\" ></td>\n" +
                      "</tr>\n" +
                      "<tr>\n" +
                      "<td nowrap align=\"right\" ><span class=\"topText\" align=\"right\">Password:&nbsp;</span><input type=\"password\" name=\"auth\" size=\"8\"></td>\n" +
                      "</tr>\n" +
                      "<tr>\n" +
                      "<td nowrap colspan=\"2\" align=\"right\" ><input type=\"checkbox\" name=\"remember\" value=\"1\" checked>&nbsp;<span " + "class=\"topText\">Remember me.</span></td>\n" +
                      "</tr>\n" +   
                      "<tr>\n" +
                      "<td align=\"right\" colspan=\"2\"><input type=\"submit\" class=\"IP\" name=\"login\" value=\"Login\">\n" +                           
                      "<a href=\"https://" + IPs.WebAddress() + "/payAsYouGoSignUp.jsp\">Register</a></td>\n" +
                      "</tr>\n" +
                
                      "</table>\n" +
                      "<script type=\"text/javascript\">\n" +
                      "<!--\n" +
                      "function checkWhiteSpace() {\n" +
                      "  var s = document.getElementById(\"uid\").value;\n"+
                      "   // Check for white space\n" +
                      "  if (s.indexOf(\" \") > -1) {\n" +
                      "      jAlert(\"The User Name that you entered contains a white space.\");\n" +
                      "      return false;\n" +
                      "  }\n" +
                      "  return true;\n" +
                      "}\n" +
                      "//-->\n" +
                      "</script>\n" +
                      "</form>\n";          
        }
      }
    

    public String getWebAddress()
    {
        return IPs.WebAddress();
    }

    public boolean getLoggedIn()
    {
        return loggedIn;
    }

    public String getName()
    {
        return name;
    }
}

这里是实际的 TestConnection 页面。

public class TestConnectionFactory {
    static final Runtime RUNTIME = Runtime.getRuntime();
    static Logger log = LogManager.getLogger(TestConnectionFactory.class.getName());
    DataSource ds = null;
    long connectCount;
    /**
     * A handle to the unique Singleton instance.
     */
    static private TestConnectionFactory instance = null;

    /**
     * The constructor could be made private
     * to prevent others from instantiating this class.
     * But this would also make it impossible to
     * create instances of Singleton subclasses.
     */
    protected TestConnectionFactory() {
        log.debug("<init> freeMemory:"+RUNTIME.freeMemory());
        if (ds == null) {
            ds = getDataSource();
        }
    }

    /**
     * @return The unique instance of this class.
     */
    static public synchronized TestConnectionFactory getInstance() {
        if (instance == null) {
            log.info("getInstance():creating new instance");
            instance = new TestConnectionFactory();
            log.debug("getInstance():reusing existing instance");
        }
        return instance;
    }

    public Connection getConnection() {
        Connection connection = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;

            try {
                connection = ds.getConnection();

            } catch (SQLException e) {
                e.printStackTrace();
            }
            return connection; 
           
    }

我试过的是指这个Java web app in tomcat periodically freezes up post 因为问题听起来与我的应用程序类似，但修复无效。我尝试过的事情：

更改 context.xml 文件中的 maxWaitMillis 和 maxActive。
增加客户端数据库连接总数。
在 Java 代码中为空用户设置陷阱。

Answer 1

更新 getConnection() 方法似乎解决了我的问题。

public Connection getConnection() {
    Connection connection = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;

        try {
            connection = ds.getConnection();

        } catch (SQLException e) {
            e.printStackTrace();
        }
        return connection; 
       
}

运行几个小时后，应用程序出现黑屏

Application hits blank screen after running for couple hours

java

mysql

jdbc

tomcat6

tomcat9

运行 几个小时后，应用程序出现黑屏

Application hits blank screen after running for couple hours

java

mysql

jdbc

tomcat6

tomcat9

运行几个小时后，应用程序出现黑屏