linux 下servlet画图不显示问题

迈不过友情╰ 2022-05-14 03:50 232阅读 0赞

　　　画图代码在windowxp和有些linux服务器上会没有问题，今天在别的机器上发现运行后卡死在Graphics2D g = buffImg.createGraphics();

由于使用了框架，但是没有看到报错。在网上找了解决方法，同时发现网上有些写法差不多但是可以捕获异常。

解决方法：

在tomcat部署目录下的bin目录里面的catalina.sh启动文件加入下面的红色字体部分就可以了（注意该文件的编码为unix）。

elif [ “$1” = “start” ] ;then
shift
touch “$CATALINA_BASE”/logs/catalina.out
if [ “$1” = “-security” ] ; then
echo “Using Security Manager”
shift
“$_RUNJAVA” $JAVA_OPTS $CATALINA_OPTS
-Djava.endorsed.dirs=”$JAVA_ENDORSED_DIRS” -classpath “$CLASSPATH”
-Djava.security.manager
-Djava.security.policy==”$CATALINA_BASE”/conf/catalina.policy
-Dcatalina.base=”$CATALINA_BASE”
-Dcatalina.home=”$CATALINA_HOME”
-Djava.io.tmpdir=”$CATALINA_TMPDIR”
-Djava.awt.headless=true
org.apache.catalina.startup.Bootstrap “$@” start

“$CATALINA_BASE”/logs/catalina.out 2>&1 &
if [ ! -z “$CATALINA_PID” ]; then
echo $! > $CATALINA_PID
fi
else
“$_RUNJAVA” $JAVA_OPTS $CATALINA_OPTS
-Djava.endorsed.dirs=”$JAVA_ENDORSED_DIRS” -classpath “$CLASSPATH”
-Dcatalina.base=”$CATALINA_BASE”
-Dcatalina.home=”$CATALINA_HOME”
-Djava.io.tmpdir=”$CATALINA_TMPDIR”
-Djava.awt.headless=true
org.apache.catalina.startup.Bootstrap “$@” start
“$CATALINA_BASE”/logs/catalina.out 2>&1 &
if [ ! -z “$CATALINA_PID” ]; then
echo $! > $CATALINA_PID
fi
fi
编辑完成后，重新启动tomcat，然后再运行画图程序，That’s OK!
经过测试，在weblogic中也可以采用类似的方法，然后画图的时候也不需要Xserver。具体的做法就是在weblogic的启动脚本startWebLogic.sh的最后部分中加入“-Djava.awt.headless=true”。如下橙色字体所示（只摘抄部分）：
….
${JAVA_HOME}/bin/java ${JAVA_VM} ${MEM_ARGS} ${JAVA_OPTIONS} -Dweblogic.Name=${SERVER_NAME} -Dweblogic.ProductionModeEnabled=${PRODUCTION_MODE} -Djava.security.policy=”${WL_HOME}/server/lib/weblogic.policy”-Djava.awt.headless=trueweblogic.Server

异常如下：

一、

  1. 500 Servlet Exception
  2. java.lang.NoClassDefFoundError
  3. at java.lang.Class.forName0(Native Method)
  4. at java.lang.Class.forName(Class.java:120)
  5. at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:58)
  6. at java.awt.image.BufferedImage.createGraphics(BufferedImage.java:1011)
  7. at java.awt.image.BufferedImage.getGraphics(BufferedImage.java:1001)
  8. at image.mvc.vc.VC.Paint(VC.java:66)
  9. at image.run.Servlet.doGet(Servlet.java:183)
  10. at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
  11. at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
  12. at com.caucho.server.http.FilterChainServlet.doFilter(FilterChainServlet.java:96)
  13. at com.caucho.server.http.Invocation.service(Invocation.java:315)
  14. at com.caucho.server.http.CacheInvocation.service(CacheInvocation.java:135)
  15. at com.caucho.server.http.RunnerRequest.handleRequest(RunnerRequest.java:346)
  16. at com.caucho.server.http.RunnerRequest.handleConnection(RunnerRequest.java:274)

  17. at com.caucho.server.TcpConnection.run(TcpConnection.java:139)

  18. at java.lang.Thread.run(Thread.java:484)

二、

[ERROR] 2005-07-21 21:16:28 org.jboss.web.localhost.Engine - StandardWrapperValve[jsp]: Servlet.service() for servlet jsp threw exception
java.lang.InternalError: Can’t connect to X11 window server using ‘:0.0’ as the value of the DISPLAY variable.
at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
at sun.awt.X11GraphicsEnvironment.(X11GraphicsEnvironment.java:134)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:141)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:62)
at java.awt.image.BufferedImage.createGraphics(BufferedImage.java:1041)
at java.awt.image.BufferedImage.getGraphics(BufferedImage.java:1031)
at com.sww.helper.Image.creatImage(Image.java:30)

三、

SEVERE: Servlet.service() for servlet validatecode threw exception
java.lang.InternalError: Can’t connect to X11 window server using ‘192.168.1.1:1.0’ as the value of the DISPLAY variable.
at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
at sun.awt.X11GraphicsEnvironment.access$100(X11GraphicsEnvironment.java:52)
at sun.awt.X11GraphicsEnvironment$1.run(X11GraphicsEnvironment.java:155)
at java.security.AccessController.doPrivileged(Native Method)
at sun.awt.X11GraphicsEnvironment.(X11GraphicsEnvironment.java:131)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:68)
at java.awt.image.BufferedImage.createGraphics(BufferedImage.java:1135)
at com.newyulong.iptv.webapp.servlet.ValidateCodeServlet.service(ValidateCodeServlet.java:53)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)
Sep 8, 2013 6:54:02 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet validatecode threw exception
java.lang.NoClassDefFoundError: Could not initialize class sun.awt.X11GraphicsEnvironment
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:68)
at java.awt.image.BufferedImage.createGraphics(BufferedImage.java:1135)
at com.newyulong.iptv.webapp.servlet.ValidateCodeServlet.service(ValidateCodeServlet.java:53)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)
Sep 8, 2013 6:54:02 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet validatecode threw exception
java.lang.NoClassDefFoundError: Could not initialize class sun.awt.X11GraphicsEnvironment
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:68)
at java.awt.image.BufferedImage.createGraphics(BufferedImage.java:1135)
at com.newyulong.iptv.webapp.servlet.ValidateCodeServlet.service(ValidateCodeServlet.java:53)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)

四、

servlet画图类部分代码：

public class ValidateCodeServlet extends HttpServlet { 

  1. /\*\*  
  2.  \*  
  3.  \*/  
  4. private static final long serialVersionUID = 1L;  
  6. int w = 60;  
  7. int h = 20;  
  8. int fh = 10;  
  9. int cy = 0;  
  10. int x = 1;  
  11. int cc = 4;  
  13. char\[\] cs = \{ 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q'  
  14.         ,'R','S','T','U','V','W','X','Y','Z', '2', '3', '4', '5', '6',  
  15.         '7', '8', '9'  
  16.         \};  
  18. protected void service(HttpServletRequest req, HttpServletResponse resp)  
  19.         throws ServletException, java.io.IOException \{  
  21.     x = w / (cc + 1);  
  22.     fh = h - 2;  
  23.     cy = h - 4;  
  25.     // image buffer  
  26.     BufferedImage buffImg = new BufferedImage(w, h,  
  27.             BufferedImage.TYPE\_INT\_RGB);  
  28.     Graphics2D g = buffImg.createGraphics();  
  30.     Random random = new Random();  
  32.     // fill image with white color  
  33.     g.setColor(Color.WHITE);  
  34.     g.fillRect(0, 0, w, h);  
  36.     // create font  
  37.     Font font = new Font("Fixedsys", Font.PLAIN | Font.BOLD, fh);  
  38.     // set font  
  39.     g.setFont(font);  
  41.     g.setColor(Color.blue);  
  42.     g.drawRect(0, 0, w - 1, h - 1);

　　　　………………………………………….. 

  1. \}

}

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