今天 发布人员反映 sitemanager 验证码 在developer/QA(内网203) 两个环境都正常,但是在 stagine 环境(正式服务器上面)死活不出来,不显示
分析了下, 我首先将 web.xml 统统注释掉,仅仅保留
<servlet>
<servlet-name>SecurityImageServlet</servlet-name>
<servlet-class>com.feilong.web.servlet.SecurityImageServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>SecurityImageServlet</servlet-name>
<url-pattern>/servlet/securityImage</url-pattern>
</servlet-mapping>
发现图片还是显示不了
异常代码:
javax.imageio.IIOException: Can't create output stream! javax.imageio.ImageIO.write(ImageIO.java:1560) com.jumbo.brandstore.util.SecurityUtil.generateSecurityImage(SecurityUtil.java:90) com.jumbo.brandstore.web.servlet.SecurityImageServlet.service(SecurityImageServlet.java:57) javax.servlet.http.HttpServlet.service(HttpServlet.java:717) root cause javax.imageio.IIOException: Can't create cache file! javax.imageio.ImageIO.createImageOutputStream(ImageIO.java:397) javax.imageio.ImageIO.write(ImageIO.java:1558) com.jumbo.brandstore.util.SecurityUtil.generateSecurityImage(SecurityUtil.java:90) com.jumbo.brandstore.web.servlet.SecurityImageServlet.service(SecurityImageServlet.java:57) javax.servlet.http.HttpServlet.service(HttpServlet.java:717) root cause java.io.IOException: No such file or directory java.io.UnixFileSystem.createFileExclusively(Native Method) java.io.File.checkAndCreate(File.java:1704) java.io.File.createTempFile(File.java:1792) javax.imageio.stream.FileCacheImageOutputStream.<init>(FileCacheImageOutputStream.java:71) com.sun.imageio.spi.OutputStreamImageOutputStreamSpi.createOutputStreamInstance(OutputStreamImageOutputStreamSpi.java:50) javax.imageio.ImageIO.createImageOutputStream(ImageIO.java:393) javax.imageio.ImageIO.write(ImageIO.java:1558) com.jumbo.brandstore.util.SecurityUtil.generateSecurityImage(SecurityUtil.java:90) com.jumbo.brandstore.web.servlet.SecurityImageServlet.service(SecurityImageServlet.java:57) javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
妖怪了, 其他项目用这个验证码 都很正常,这台服务器上有 stagine-frontend2, 这个应用的 验证码也是正常的
1.可以 修改验证码程序
把
ImageIO.write(image, "jpeg", response.getOutputStream());
修改为
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(response.getOutputStream());
encoder.encode(image);
2.tomcat 的temp 目录必须有
一打听, 原来 tomcat -sitemanager 的temp 目录 删除过,而frontend 里面的保留着
为什么 ImageIO.write 这种方式 需要 temp 目录 呢?
带着疑问,看看源码(Java的开源好处真心不错) :
public static ImageOutputStream createImageOutputStream(Object output) throws IOException { if (output == null) { throw new IllegalArgumentException("output == null!"); } Iterator iter; // Ensure category is present try { iter = theRegistry.getServiceProviders(ImageOutputStreamSpi.class, true); } catch (IllegalArgumentException e) { return null; } boolean usecache = getUseCache() && hasCachePermission(); while (iter.hasNext()) { ImageOutputStreamSpi spi = (ImageOutputStreamSpi)iter.next(); if (spi.getOutputClass().isInstance(output)) { try { return spi.createOutputStreamInstance(output, usecache, getCacheDirectory()); } catch (IOException e) { throw new IIOException("Can't create cache file!", e); } } } return null; }
会调用 cache 文件夹 ,他所谓的cache 文件夹是怎么样定义的呢?
private static boolean hasCachePermission() { Boolean hasPermission = getCacheInfo().getHasPermission(); if (hasPermission != null) { return hasPermission.booleanValue(); } else { try { SecurityManager security = System.getSecurityManager(); if (security != null) { File cachedir = getCacheDirectory(); String cachepath; if (cachedir != null) { cachepath = cachedir.getPath(); } else { cachepath = getTempDir(); if (cachepath == null) { getCacheInfo().setHasPermission(Boolean.FALSE); return false; } } security.checkWrite(cachepath); } } catch (SecurityException e) { getCacheInfo().setHasPermission(Boolean.FALSE); return false; } getCacheInfo().setHasPermission(Boolean.TRUE); return true; } }
写得也很清楚,如果自己设置了 set
CacheDirectory 那么会使用自定义的,否则调用
getTempDir()
/** * Returns the default temporary (cache) directory as defined by the * java.io.tmpdir system property. */ private static String getTempDir() { GetPropertyAction a = new GetPropertyAction("java.io.tmpdir"); return (String)AccessController.doPrivileged(a); }
Oh, 会读取变量java.io.tmpdir!
大家还记得 tomcat 启动的时候,会显示
Using CATALINA_BASE: /home/appuser/appservers/tomcat-feilong Using CATALINA_HOME: /home/appuser/appservers/tomcat-feilong Using CATALINA_TMPDIR: /home/appuser/appservers/tomcat-feilong/temp Using JRE_HOME: /usr/lib/jvm/java-6-sun Using CLASSPATH: /home/appuser/appservers/tomcat-feilong/bin/bootstrap.jar
$CATALINA_TMPDIR 这个变量就是 我们的temp 文件夹
而tomcat 启动的时候,调用jvm会设置 java.io.tmpdir 参数
看
rem CATALINA_TMPDIR (Optional) Directory path location of temporary directory
rem the JVM should use (java.io.tmpdir). Defaults to
rem %CATALINA_BASE%\temp.
%_EXECJAVA% %JAVA_OPTS% %CATALINA_OPTS% %DEBUG_OPTS% -Djava.endorsed.dirs="%JAVA_ENDORSED_DIRS%" -classpath "%CLASSPATH%" -Dcatalina.base="%CATALINA_BASE%" -Dcatalina.home="%CATALINA_HOME%" -Djava.io.tmpdir="%CATALINA_TMPDIR%" %MAINCLASS% %CMD_LINE_ARGS% %ACTION%
这下终于弄明白了, ImageIO.write(image, "JPEG", os) 这种方式 来生成图片、验证码 tomcat必须要有temp文件夹的来龙去脉了