How to solve the Http://mirror.centos.org/centos/5/addons/x86_64/repodata/repomd.xml error

Find Yum source hint error:
Loaded Plugins:fastestmirror
Determining fastest Mirrors
* base:mirror.neu.edu.cn
* extras:mirror.neu.edu.cn
* updates:mirror.neu.edu.cn

Trying other mirror.
Error:cannot Retrieve repository metadata (Repomd.xml) for repository:addons. Please verify its path and try again

============================================ resolution Method ===========================================

1. CD/ETC/YUM.REPOS.D
2. [Root@localhost yum.repos.d]# CP Centos-base.repo Centos-base.repo.bak
[Root@localhost yum.repos.d]#: >centos-base.repo
[Root@localhost yum.repos.d]# VI Centos-base.repo

3. Copy the above content
[Base]
name=centos-$releasever-base
#mirrorlist =http://mirrors.163.com/?release= $releasever &arch= $basearch &repo=os
baseurl=http://mirrors.163.com/centos/$releasever/os/$basearch/
Gpgcheck=1
Gpgkey=http://mirrors.163.com/centos/devel/rpm-gpg-key-centos-5

#released Updates
[UPDATE]
name=centos-$releasever-updates
#mirrorlist =http://mirrors.163.com/?release= $releasever &arch= $basearch &repo=updates
baseurl=http://mirrors.163.com/centos/$releasever/updates/$basearch/
Gpgcheck=1
Gpgkey=http://mirrors.163.com/centos/devel/rpm-gpg-key-centos-5

#packages used/produced in the builds but not released
[Addons]
name=centos-$releasever-addons
#mirrorlist =http://mirrors.163.com/?release= $releasever &arch= $basearch &repo=addons
baseurl=http://mirrors.163.com/centos/$releasever/addons/$basearch/
Gpgcheck=1
Gpgkey=http://mirrors.163.com/centos/devel/rpm-gpg-key-centos-5

#additional packages that useful
[Extras]
name=centos-$releasever-extras
#mirrorlist =http://mirrors.163.com/?release= $releasever &arch= $basearch &repo=extras
baseurl=http://mirrors.163.com/centos/$releasever/extras/$basearch/
Gpgcheck=1
Gpgkey=http://mirrors.163.com/centos/devel/rpm-gpg-key-centos-5

#additional packages that extend functionality of existing packages
[Centosplus]
name=centos-$releasever-plus
#mirrorlist =http://mirrors.163.com/?release= $releasever &arch= $basearch &repo=centosplus
baseurl=http://mirrors.163.com/centos/$releasever/centosplus/$basearch/
Gpgcheck=1
Enabled=1
Gpgkey=http://mirrors.163.com/centos/devel/rpm-gpg-key-centos-5

#contrib-packages by Centos Users
[Contrib]
name=centos-$releasever-contrib
#mirrorlist =http://mirrors.163.com/?release= $releasever &arch= $basearch &repo=contrib
baseurl=http://mirrors.163.com/centos/$releasever/contrib/$basearch/
Gpgcheck=1
Enabled=0
Gpgkey=http://mirrors.163.com/centos/devel/rpm-gpg-key-centos-5

4. When you install the file, you will be prompted: GPG key retrieval failed: [Errno] HTTP Error 404:not Found
5. Method of emancipation: Yum install vsftp*--nogpgcheck

If there is a hint:

Is this OK [y/n]: Y
Downloading Packages:
warning:rpmts_HdrFromFdno:Header V3 DSA signature:nokey, key ID e8562897

RHA5 Solution:
RPM--import http://centos.ustc.edu.cn/centos/RPM-GPG-KEY-CentOS-5

If it is a low version, you can use the
RPM--import Http://centos.ustc.edu.cn/centos/RPM-GPG-KEY-centos4