[root@localhost yum.repos.d]# yum makecache     #缓存YUM源信息Loaded plugins: fastestmirrorDetermining fastest mirrorscentos7-local                                                                             | 3.6 kB  00:00:00     (1/4): centos7-local/group_gz                                                             | 156 kB  00:00:00     (2/4): centos7-local/filelists_db                                                         | 3.1 MB  00:00:00     (3/4): centos7-local/primary_db                                                           | 3.1 MB  00:00:00     (4/4): centos7-local/other_db                                                             | 1.2 MB  00:00:00     Metadata Cache Created

[root@localhost yum.repos.d]# yum repolistLoaded plugins: fastestmirrorLoading mirror speeds from cached hostfilerepo id                                                 repo name                                          statuscentos7-local                                           Centos7                                            3894repolist: 3894

[root@localhost yum.repos.d]# yum install net-tools

[root@localhost yum.repos.d]# yum search jdk   #也可搜素