我们已经为Sybase服务器开发了基于Web的监视应用程序，并且在生产环境中使用jfree生成图形时遇到了问题。
我们通常在QA机器上构建和测试我们的应用程序，然后将构建的* .war文件通过ftp发送到生产环境。
当完全相同的代码片段无法在生产环境中生成图形时，在生产环境中就会出现问题。
以下是我们要导入的类和包：
package var;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Timestamp;
import java.text.Format;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.HashSet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.CategoryLabelPositions;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.axis.DateAxis;
import org.jfree.data.time.Minute;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;
import org.jfree.data.xy.XYDataset;
import java.sql.DriverManager;
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.sql.*;
import javax.naming.*;
import org.jfree.ui.RectangleInsets;
import java.awt.GraphicsEnvironment;
以下是我们认为会引发错误的代码段：
else
{
int interval=Integer.parseInt(request.getParameter("interval").toString());
System.out.println("I Before OS Level Object creation");
OSLevel osl=new OSLevel();
width=1500;
height=500;
XYDataset mdaDataSet=null;
try
{
System.out.println("I Before XY Dataset generation");
mdaDataSet=osl.generateXYDataSet(start, end, dval3, cpuval3, dsql3,interval);
CategoryPlot plotmda = null;
System.out.println("I Before Time Series generation");
chartos = ChartFactory.createTimeSeriesChart(
title, // chart title
"Time", // domain axis label
"CPU Usage Percentage", // range axis label
mdaDataSet, // data
true, // include legend
true, // tooltips
false // urls
);
System.out.println("The title is:"+title);
}
catch(Exception e)
{
System.out.println("I am in the Chart Generation TRY Block");
e.printStackTrace();
}
最后是质量检查中的server.log条目，然后是生产中的条目：
the query is:SELECT CPUUsed,DateTime FROM bureau.bp_mda_cpu WHERE (DateTime > '2013-07-11' and DateTime < '2013-07-18') and ClientID='G123'
I Before OS Level Object creation
I Before XY Dataset generation
I Before Time Series generation
The title is:MITSUBISHI_GLOSS Sybase CPU(MDA CPU report)
The File Path is:/tmp/tmpChart148725123563269780.tmp
END of the report
the query is:SELECT CPUUsed,DateTime FROM bureau.bp_mda_cpu WHERE (DateTime > '2013-07-11' and DateTime < '2013-07-18') and ClientID='G123'
I Before OS Level Object creation
I Before XY Dataset generation
I Before Time Series generation
Jul 18, 2013 9:52:07 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet GenerateDBReport threw exception
javax.servlet.ServletException: Servlet execution threw an exception
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:311)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:263)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:562)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1018)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:196)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:499)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:149)
at org.apache.catalina.valves.CertificatesValve.invoke(CertificatesValve.java:246)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:149)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:562)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1018)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2748)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:186)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:149)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:149)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:562)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1018)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:163)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:512)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:149)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:562)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1018)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:199)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:637)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:463)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:568)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:631)
at java.lang.Thread.run(Thread.java:662)
稍微更改代码行后，出现以下新错误：
java.lang.NoClassDefFoundError: Could not initialize class org.jfree.chart.JFreeChart
at org.jfree.chart.ChartFactory.createLineChart(ChartFactory.java:1242)
at var.DatabaseLevelReport.doGet(Unknown Source)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
这看起来像一个已知问题，但我仍然无法解决：
See here和
here
最佳答案
所以最终问题解决了。错误基本上是jfree对象无法启动。
jfree构造函数尝试进行一些静态初始化，但其中失败了。
即使是在类路径中，其原因仍是以下jar：
gnome-java-bridge.jar
只需在accessibility.properties文件中注释掉类名，就可以防止Java尝试加载该类。
这看起来像一个已知问题：
Reference1
Reference2
之后，一切工作都非常正常！
感谢你的帮助！非常感激。