环境：
centos6.5 32位
oracle jdk 1.8
tomcat 7
问题：
yum install tomcat后，返回如下错误：
[root@centos]~# curl -v http://localhost:8080 * About to connect() to localhost port 8080 (#0) * Trying 127.0.0.1... connected * Connected to localhost (127.0.0.1) port 8080 (#0) > GET / HTTP/1.1 > User-Agent: curl/7.19.7 (i386-redhat-linux-gnu) libcurl/7.19.7 NSS/3.21 Basic ECC zlib/1.2.3 libidn/1.18 libssh2/1.4.2 > Host: localhost:8080 > Accept: */* > < HTTP/1.1 500 Internal Server Error < Server: Apache-Coyote/1.1 < Content-Type: text/html;charset=utf-8 < Content-Language: en < Content-Length: 2655 < Date: Thu, 15 Sep 2016 03:03:16 GMT < Connection: close < <html><head><title>Apache Tomcat/7.0.65 - Error report</title><style><!--H1 {font-family:Tahoma,Arial,sans-serif;color:white;font-size:22px;} H2 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:16px;} H3 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:14px;} BODY {font-family:Tahoma,Arial,sans-serif;color:black;background-color:white;} B {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;} P {font-family:Tahoma,Arial,sans-serif;background:white;color:black;font-size:12px;}A {color : black;}A.name {color : black;}HR {color : #525D76;}--></style> </head><body><h1>HTTP Status 500 - Unable to compile class for JSP: </h1><HR size="1" noshade="noshade"><p><b>type</b> Exception report</p><p><b>message</b> <u>Unable to compile class for JSP: </u></p><p><b>description</b> <u>The server encountered an internal error that prevented it from fulfilling this request.</u></p><p><b>exception</b> <pre>org.apache.jasper.JasperException: Unable to compile class for JSP: An error occurred at line: [1] in the generated java file: [/usr/share/tomcat/work/Catalina/localhost/_/org/apache/jsp/index_jsp.java] The type java.util.Map$Entry cannot be resolved. It is indirectly referenced from required .class files An error occurred at line: [1] in the generated java file: [/usr/share/tomcat/work/Catalina/localhost/_/org/apache/jsp/index_jsp.java] The type java.io.ObjectInputStream cannot be resolved. It is indirectly referenced from required .class files Stacktrace: org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:103) org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:366) org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:466) org.apache.jasper.compiler.Compiler.compile(Compiler.java:379) org.apache.jasper.compiler.Compiler.compile(Compiler.java:354) org.apache.jasper.compiler.Compiler.compile(Compiler.java:341) org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:662) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:364) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339) javax.servlet.http.HttpServlet.service(HttpServlet.java:731) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) * Closing connection #0 #
网友介绍这是ecj.jar太老了。网友的版本事3.4.2，换4.2后ok。看下自己的ecj
[root@centos]/usr/share/java# ll|grep ecj -rw-r--r-- 1 root root 1442090 11月 11 2010 ecj-3.4.2.jar lrwxrwxrwx 1 root root 13 9月 15 00:53 ecj.jar -> ecj-3.4.2.jar lrwxrwxrwx 1 root root 13 9月 15 00:53 eclipse-ecj-3.4.2.jar -> ecj-3.4.2.jar lrwxrwxrwx 1 root root 21 9月 15 00:53 eclipse-ecj.jar -> eclipse-ecj-3.4.2.jar lrwxrwxrwx 1 root root 13 9月 15 00:53 jdtcore.jar -> ecj-3.4.2.jar
果然很老。
那么打开ecj看下， 果然很多编译相关的类啊！
http://wiki.jikexueyuan.com/project/tomcat/classloading.html
用ecj-4.4.2.jar 替换老版本ecj后，重启tomcat，关闭防火墙，访问网页
done