创建软链接及解决项目内的软链访问报404的问题

实例：ln -s /home/gamestat    /gamestat

 
linux下的软链接类似于windows下的快捷方式
 
ln -s a b 中的
a 就是源文件，b是链接文件名,其作用是当进入b目录，实际上是链接进入了a目录
如上面的示例，当我们执行命令   cd /gamestat/的时候  实际上是进入了 /home/gamestat/
 
值得注意的是执行命令的时候,应该是a目录已经建立，目录b没有建立。我最开始操作的是也把b目录给建立了，结果就不对了

[root@iZbp1eqd771ku506fyee6yZ storage-sc]# ln -s /data/resource/ueditor ./ueditor

[root@iZbp1eqd771ku506fyee6yZ storage-sc]# ls

config.json  controller.jsp  index.jsp  META-INF  ueditor  WEB-INF

[root@iZbp1eqd771ku506fyee6yZ storage-sc]# cd ueditor/



特别需要说明的是，我们在项目下创建的软链默认是不能被外界访问的，要解决这个问题我们得修改tomcat的配置文件，但是修改之前，我们得先看看我们的tomcat的版本是多少，如下所示，可以看到我使用的tomcat的版本是9.0.0
[root@dev bin]# ./version.sh 

Using CATALINA_BASE:   /root/tomcat/server/storage1

Using CATALINA_HOME:   /root/tomcat/server/storage1

Using CATALINA_TMPDIR: /root/tomcat/server/storage1/temp

Using JRE_HOME:        /home/data/jdk1.8.0_102

Using CLASSPATH:       /root/tomcat/server/storage1/bin/bootstrap.jar:/root/tomcat/server/storage1/bin/tomcat-juli.jar

Server version: Apache Tomcat/9.0.0.M10

Server built:   Aug 31 2016 15:00:21 UTC

Server number:  9.0.0.0

OS Name:        Linux

OS Version:     3.10.0-327.36.3.el7.x86_64

Architecture:   amd64

JVM Version:    1.8.0_102-b14

JVM Vendor:     Oracle Corporation

[root@dev bin]# 

 下面我们到tomcat下找到context.xml文件，如下所示。
[root@dev storage1]# ls
bin  conf  lib  LICENSE  logs  NOTICE  RELEASE-NOTES  RUNNING.txt  SESSIONS.ser  storage-sc  temp  webapps  work
[root@dev storage1]# cd conf
[root@dev conf]# ls
Catalina  catalina.policy  catalina.properties  context.xml
 jaspic-providers.xml  jaspic-providers.xsd  logging.properties  server.xml  tomcat-users.xml  tomcat-users.xsd  web.xml
[root@dev conf]# 

 不同版本的tomcat对context.xml的修改是不一样的，如果是tomcat7及以下版本，那么修改如下，也就是在<Context 后添加了allowLinking="true"这么一句话。
<Context allowLinking="true">

    <!-- Default set of monitored resources. If one of these changes, the    -->

    <!-- web application will be reloaded.                                   -->

    <WatchedResource>WEB-INF/web.xml</WatchedResource>

    <WatchedResource>${catalina.base}/conf/web.xml</WatchedResource>

    <!-- Uncomment this to disable session persistence across Tomcat restarts -->

    <!--

    <Manager pathname="" />

    -->

</Context>

如果是tomcat8及其以上版本的话，修改如下，就是在<Context>的下方添加了 一行<Resources allowLinking="true" />，这样就可以访问了！！
<Context>

    <Resources allowLinking="true" />

    <!-- Default set of monitored resources. If one of these changes, the    -->

    <!-- web application will be reloaded.                                   -->

    <WatchedResource>WEB-INF/web.xml</WatchedResource>

    <WatchedResource>${catalina.base}/conf/web.xml</WatchedResource>

    <!-- Uncomment this to disable session persistence across Tomcat restarts -->

    <!--

    <Manager pathname="" />

    -->

</Context>

 
删除软链接：
   rm -rf  b  注意不是rm
-rf  b/
 
ln  a b 是建立硬链接
建立链接的使用方法如下：
 
 
[root@WEB_YQ_64_79 /]# ln --help
Usage: ln [OPTION]... [-T] TARGET LINK_NAME   (1st form)
  or:  ln [OPTION]... TARGET                  (2nd form)
  or:  ln [OPTION]... TARGET... DIRECTORY     (3rd form)
  or:  ln [OPTION]... -t DIRECTORY TARGET...  (4th form)
In the 1st form, create a link to TARGET with the name LINK_NAME.
In the 2nd form, create a link to TARGET in the current directory.
In the 3rd and 4th forms, create links to each TARGET in DIRECTORY.
Create hard links by default, symbolic links with --symbolic.
When creating hard links, each TARGET must exist.
 
Mandatory arguments to long options are mandatory for short options too.
      --backup[=CONTROL]      make a backup of each existing destination file
  -b                          like --backup but does not accept an argument
  -d, -F, --directory         allow the superuser to attempt to hard link
                                directories (note: will probably fail due to
                                system restrictions, even for the superuser)
  -f, --force                 remove existing destination files
  -n, --no-dereference        treat destination that is a symlink to a
                                directory as if it were a normal file
  -i, --interactive           prompt whether to remove destinations
  -s, --symbolic              make symbolic links instead of hard links
  -S, --suffix=SUFFIX         override the usual backup suffix
  -t, --target-directory=DIRECTORY  specify the DIRECTORY in which to create
                                the links
  -T, --no-target-directory   treat LINK_NAME as a normal file
  -v, --verbose               print name of each file before linking
      --help     display this help and exit
      --version  output version information and exit
 
The backup suffix is `~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.
The version control method may be selected via the --backup option or through
the VERSION_CONTROL environment variable.  Here are the values:
 
  none, off       never make backups (even if --backup is given)
  numbered, t     make numbered backups
  existing, nil   numbered if numbered backups exist, simple otherwise
  simple, never   always make simple backups
 
Report bugs to <bug-coreutils@gnu.org>.