初用网易蜂巢遇到的问题

网易蜂巢是网易推出的一个基于docker容器技术的云服务，最近需要用到网易蜂巢的容器。

可以直接用支持ssh连接的终端连到蜂巢

ssh -i id_rsa root@106.2.61.90

蜂巢用的是debian系统

root@sxplus-170598-2252272e-hl3nx:~# cat /etc/issue
Debian GNU/Linux 7 
 l

将项目从github克隆到蜂巢

git clone https://github.com/scarlettxu/restaurant.git

因为蜂巢没有publickey，所以用https协议

编译打包项目

mvn package

将项目包拷贝到tomcat

cp *.war /var/lib/tomcat7/webapps

在浏览器访问发布的服务

http://106.2.61.90:8080/restaurant/noodles

出现了如下错误

type Exception report

message com/sx/NoodlesServlet : Unsupported major.minor version 51.0 (unable to load class com.sx.NoodlesServlet)

description The server encountered an internal error (com/sx/NoodlesServlet : Unsupported major.minor version 51.0 (unable to load class com.sx.NoodlesServlet)) that prevented it from fulfilling this request.

exception

java.lang.UnsupportedClassVersionError: com/sx/NoodlesServlet : Unsupported major.minor version 51.0 (unable to load class com.sx.NoodlesServlet)
	org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2905)
	org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1170)
	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1678)
	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1556)
	org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:461)
	org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
	org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
	org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
	org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1003)
	org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
	org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	java.lang.Thread.run(Thread.java:701)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.28 logs.

这个由于编译项目所用的java版本和运行是用的java版本不同

maven打包时所用的java版本

root@sxplus-170598-2252272e-hl3nx:/usr/lib/jvm/default-java/jre# mvn -version
Apache Maven 3.0.4
Maven home: /usr/share/maven
Java version: 1.7.0_95, vendor: Oracle Corporation
Java home: /usr/lib/jvm/java-7-openjdk-amd64/jre
Default locale: en_US, platform encoding: ANSI_X3.4-1968
OS name: "linux", version: "3.18.20-nce-amd64", arch: "amd64", family: "unix"

tomcat运行用的default java

root@sxplus-170598-2252272e-hl3nx:/usr/lib/jvm/default-java/jre# ps -ef|grep tomcat
root         1     0  0 10:27 ?        00:00:00 /bin/sh -c /etc/init.d/tomcat7 start && /etc/init.d/mysql start && /usr/sbin/sshd -D
tomcat7   1601     1  2 11:20 ?        00:00:03 /usr/lib/jvm/default-java/bin/java -Djava.util.logging.config.file=/var/lib/tomcat7/conf/logging.properties -Djava.awt.headless=true -Xmx128m -XX:+UseConcMarkSweepGC -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/usr/share/tomcat7/endorsed -classpath /usr/share/tomcat7/bin/bootstrap.jar:/usr/share/tomcat7/bin/tomcat-juli.jar -Dcatalina.base=/var/lib/tomcat7 -Dcatalina.home=/usr/share/tomcat7 -Djava.io.tmpdir=/tmp/tomcat7-tomcat7-tmp org.apache.catalina.startup.Bootstrap start
root      1643   483  0 11:22 pts/0    00:00:00 grep tomcat

default java 版本

root@sxplus-170598-2252272e-hl3nx:/# java -version
java version "1.6.0_38"
OpenJDK Runtime Environment (IcedTea6 1.13.10) (6b38-1.13.10-1~deb7u1)
OpenJDK 64-Bit Server VM (build 23.25-b01, mixed mode)

查看安装的所有java版本和default版本

root@sxplus-170598-2252272e-hl3nx:/usr/lib/jvm/default-java/jre# update-alternatives --display java
java - auto mode
  link currently points to /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java
/usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java - priority 1061
  slave java.1.gz: /usr/lib/jvm/java-6-openjdk-amd64/jre/man/man1/java.1.gz
/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java - priority 1051
  slave java.1.gz: /usr/lib/jvm/java-7-openjdk-amd64/jre/man/man1/java.1.gz
Current 'best' version is '/usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java'.

更改default java版本

root@sxplus-170598-2252272e-hl3nx:/usr/lib/jvm/default-java/jre# update-alternatives --config java
There are 2 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                            Priority   Status
------------------------------------------------------------
* 0            /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java   1061      auto mode
  1            /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java   1061      manual mode
  2            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1051      manual mode

Press enter to keep the current choice[*], or type selection number: 2
update-alternatives: using /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java to provide /usr/bin/java (java) in manual mode

更改后的java版本

root@sxplus-170598-2252272e-hl3nx:/usr/lib/jvm/default-java/jre# java -version
java version "1.7.0_95"
OpenJDK Runtime Environment (IcedTea 2.6.4) (7u95-2.6.4-1~deb7u1)
OpenJDK 64-Bit Server VM (build 24.95-b01, mixed mode)

 这还没有解决问题，最后是更改了项目里面的pom.xml里面的编译的版本，从1.6改为1.7，才解决了问题

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
        <source>1.6</source>
        <target>1.6</target>
        <encoding>UTF-8</encoding>
    </configuration>
</plugin>