标签：http
1、请描述一次完整的http请求处理过程；
(1)建立或处理连接：接收请求或拒绝请求；
(2)接收请求：接收来自于网络上的主机请求报文中对某特定资源的一次请求的过程；
(3)处理请求：对请求报文进行解析，获取客户端请求的资源及请求方法等相关信息；
(4)访问资源：获取请求报文中请求的资源；
(5)构建响应报文：
(6)发送响应报文：
(7)记录日志：
2、httpd所支持的处理模型有哪些，他们的分别使用于哪些环境。
MPM：Multipath Processing Modules(多路处理模块)
(1)prefork：多进程模型，每个进程响应一个请求；
一个主进程：负责生成子进程及回收子进程；负责创建套接字；负责接收请求，并将其派发给某子进程进行处理；
n个子进程：每个子进程处理一个请求；
工作模型：会预先生成几个空闲进程，随时等待用于响应用户请求；最大空闲和最小空闲；
特点及运用环境：每个工作进程响应一个用户请求，即使当前没有用户请求，它亦会预先生成多个空闲进程，随时等待请求连接，这样的好处是服务器不用等到请求到达时，才去临时建立进程，缩短了进程创建的时间，提高连接效率。但受限于linux的特性，工作进程数上限为1024个，如果超出该数量，服务器性能会急剧降低。因而，prefork模型的最大并发连接数量为1024。由于每个工作进程相对独立，就算崩溃了也不会对其它进程有明显影响。所以，该模型的特点是稳定可靠，适合于并发量适中而又追求稳定的用户使用。
(2)worker：多进程多线程模型，每线程处理一个用户请求；
一个主进程：负责生成子进程；负责创建套接字；负责接收请求，并将其派发给某子进程进行处理；
多个子进程：每个子进程负责生成多个线程；
每个线程：负责响应用户请求；
并发响应数量：m*n
m：子进程数量
n：每个子进程所能创建的最大线程数量；
特点及运用环境：由于在linux中，原生不支持线程，且进程本身就足够轻量化，与线程的区别不是很大，因而worker模型在linux环境中的实际性能表现与prefork相差无几。
(3)event：事件驱动模型，多进程模型，每个进程响应多个请求；
一个主进程 ：负责生成子进程；负责创建套接字；负责接收请求，并将其派发给某子进程进行处理；
子进程：基于事件驱动机制直接响应多个请求；
并发响应数量：m*n
m：子进程数量
n：每个子进程所能响应客户请求数量；
httpd-2.2(CentOS 6)：仍为测试使用模型；
httpd-2.4(CentOS 7)：event可生产环境中使用；
特点及运用环境：event的并发数量和worker类似，同样可达到m*n个。同时，因为event的子进程为一对多，节省大量CPU进程切换上下文的时间，也没有了linux系统的1024个进程限制。所以，event模型是三种模型中效率最高的一种，可以突破10K的限制(即并发数1W)，对海量的系统特别适用。
3、源码编译安装LAMP环境（基于wordpress程序），并写出详细的安装、配置、测试过程。
实验环境：CentOS 7.2(192.168.1.11) + httpd-2.4.9 + mariadb-5.5.57 + php-5.4.26 + wordpress-4.8.1
1、安装开发环境包组
[root@localhost ~]# yum groupinstall -y "Development Tools" "Server Platform Development"
2、安装开发程序包
[root@localhost ~]# yum install -y openssl-devel pcre-devel
3、编译安装httpd-2.4.9(由于安装http-2.4依赖于apr及apr-util 1.4以上版本，先对这2个软件包进行编译安装)
(1)编译安装apr-1.5.0
[root@localhost ~]# tar xf apr-1.5.0.tar.bz2 [root@localhost ~]# cd apr-1.5.0/ [root@localhost apr-1.5.0]# ./configure --prefix=/usr/local/apr [root@localhost apr-1.5.0]# make && make install
(2)编译安装apr-util-1.5.3
[root@localhost ~]# tar xf apr-util-1.5.3.tar.bz2 [root@localhost ~]# cd apr-util-1.5.3/ [root@localhost apr-util-1.5.3]# ./configure --prefix=/usr/local/apr-util --with-apr=/usr/local/apr [root@localhost apr-util-1.5.3]# make && make install
(3)编译安装httpd-2.4.9
[root@localhost ~]# tar xf httpd-2.4.9.tar.bz2 [root@localhost ~]# cd httpd-2.4.9/ [root@localhost httpd-2.4.9]# ./configure --prefix=/usr/local/apache24 --sysconfdir=/etc/httpd24 --enable-so --enable-ssl --enable-cgi --enable-rewrite --enable-zlib --with-pcre --with-apr=/usr/local/apr --with-apr-util=/usr/local/apr-util --enable-modules=most --enable-mpms-shared=all --with-mpm=prefork [root@localhost httpd-2.4.9]# make && make install
(4)将新编译的httpd24的bin目录加入PATH环境变量并重新读取该配置文件
[root@localhost ~]# vim /etc/profile.d/httpd24.sh export PATH=/usr/local/apache24/bin:$PATH [root@localhost ~]# . /etc/profile.d/httpd24.sh
(5)导出httpd头文件链接至系统头文件路径/usr/include/apache24
[root@localhost ~]# ln -sv /usr/local/apache24/include/ /usr/include/apache24 ‘/usr/include/apache24’ -> ‘/usr/local/apache24/include/’
(6)用apache自带的apachectl启动编译好的httpd，查看端口并测试自带的测试页面
[root@localhost ~]# apachectl start [root@localhost ~]# ss -tnl | grep :80 LISTEN 0 128 :::80 :::* [root@localhost ~]# curl http://192.168.1.11 <html><body><h1>It works!</h1></body></html>
4、编译安装mariadb-5.5.57
(1)准备数据目录/mydata/data
[root@localhost ~]# mkdir -pv /mydata/data
(2)创建mysql用户并修改数据目录权限
[root@localhost ~]# id mysql id: mysql: no such user [root@localhost ~]# useradd -r mysql [root@localhost ~]# id mysql uid=988(mysql) gid=983(mysql) groups=983(mysql) [root@localhost ~]# chown -R mysql.mysql /mydata/data/ [root@localhost ~]# ls -ld /mydata/data/ drwxr-xr-x. 2 mysql mysql 6 Sep 23 16:44 /mydata/data/
(3)编译安装mariadb-5.5.57
[root@localhost ~]# tar xf mariadb-5.5.57-linux-systemd-x86_64.tar.gz -C /usr/local/ [root@localhost ~]# cd /usr/local/ [root@localhost local]# ln -sv mariadb-5.5.57-linux-systemd-x86_64/ mysql ‘mysql’ -> ‘mariadb-5.5.57-linux-systemd-x86_64/’ [root@localhost local]# cd mysql/ [root@localhost mysql]# chown -R root.mysql ./* [root@localhost mysql]# scripts/mysql_install_db --user=mysql --datadir=/mydata/data [root@localhost mysql]# ls /mydata/data/ aria_log.00000001 aria_log_control mysql performance_schema test
(4)为mysql提供配置文件
[root@localhost mysql]# cp support-files/my-large.cnf /etc/my.cnf cp: overwrite ‘/etc/my.cnf’? y [root@localhost mysql]# vim /etc/my.cnf
在[mysqld]下添加以下3个选项
datadir = /mydata/data innodb_file_per_table = ON skip_name_resolve = ON
(5)为mysql提供SysV服务
[root@localhost mysql]# cp support-files/mysql.server /etc/rc.d/init.d/mysqld [root@localhost mysql]# chkconfig --add mysqld
(6)将新编译的mysql的bin目录加入PATH环境变量并重新读取该配置文件
[root@localhost mysql]# vim /etc/profile.d/mysql.sh export PATH=/usr/local/mysql/bin:$PATH [root@localhost mysql]# . /etc/profile.d/mysql.sh
(7)导出mysql头文件链接至系统头文件路径/usr/include/mysql
[root@localhost ~]# ln -sv /usr/local/mysql/include /usr/include/mysql ‘/usr/include/mysql’ -> ‘/usr/local/mysql/include’
(8)添加mysql库文件链接至系统头文件路径/usr/include/mysql
[root@localhost ~]# vim /etc/ld.so.conf.d/mysql.conf /usr/local/mysql/lib [root@localhost ~]# ldconfig -v [root@localhost ~]# ldconfig -p | grep mysql libmysqld.so.18 (libc6,x86-64) => /usr/local/mysql/lib/libmysqld.so.18 libmysqld.so (libc6,x86-64) => /usr/local/mysql/lib/libmysqld.so libmysqlclient.so.18 (libc6,x86-64) => /usr/lib64/mysql/libmysqlclient.so.18 libmysqlclient.so.18 (libc6,x86-64) => /usr/local/mysql/lib/libmysqlclient.so.18 libmysqlclient.so (libc6,x86-64) => /usr/local/mysql/lib/libmysqlclient.so
(9)启动编译好的mysqld服务，查看3306端口是否运行
[root@localhost ~]# service mysqld start [root@localhost ~]# ss -tnl | grep 3306 LISTEN 0 50 *:3306 *:*
5、编译安装php-5.4.26
(1)安装编译php需要用到的软件包
[root@localhost ~]# yum install -y libxml2-devel libmcrypt-devel bzip2-devel
(2)编译安装php-5.4.26
[root@localhost ~]# tar xf php-5.4.26.tar.bz2 [root@localhost ~]# cd php-5.4.26/ [root@localhost php-5.4.26]# ./configure --prefix=/usr/local/php --with-mysql=/usr/local/mysql --with-openssl --with-mysqli=/usr/local/mysql/bin/mysql_config --enable-mbstring --with-png-dir --with-jpeg-dir --with-freetype-dir --with-zlib --with-libxml-dir=/usr --enable-xml --enable-sockets --with-apxs2=/usr/local/apache24/bin/apxs --with-mcrypt --with-config-file-path=/etc --with-config-file-scan-dir=/etc/php.d --with-bz2 [root@localhost php-5.4.26]# make && make install
(3)为php提供配置文件，编辑httpd配置文件使其支持php，并提供php测试页
[root@localhost php-5.4.26]# cp php.ini-production /etc/php.ini [root@localhost php-5.4.26]# vim /etc/httpd24/httpd.conf AddType application/x-httpd-php .php AddType application/x-httpd-php-source .phps DirectoryIndex index.php index.html [root@localhost php-5.4.26]# vim /usr/local/apache24/htdocs/index.php <h1>phptest</h1> <?php phpinfo(); ?>
(4)重启httpd服务，测试php测试页是否能正常访问
[root@localhost php-5.4.26]# apachectl restart
6、安装配置wordpress-4.8.1
(1)下载并解压wordpress-4.8.1至/usr/local/apache24/htdocs
[root@localhost ~]# wget https://cn.wordpress.org/wordpress-4.8.1-zh_CN.tar.gz [root@localhost ~]# tar xf wordpress-4.8.1-zh_CN.tar.gz -C /usr/local/apache24/htdocs/ [root@localhost ~]# chown -R root.root /usr/local/apache24/htdocs/wordpress/ [root@localhost ~]# cd /usr/local/apache24/htdocs/wordpress/
(2)为wordpress提供php配置文件，创建wpdb数据库及授权相关权限
[root@localhost wordpress]# cp wp-config-sample.php wp-config.php [root@localhost wordpress]# vim wp-config.php define(‘DB_NAME‘, ‘wpdb‘); define(‘DB_USER‘, ‘wpuser‘); define(‘DB_PASSWORD‘, ‘wppassword‘); [root@localhost ~]# mysql Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 2 Server version: 5.5.57-MariaDB MariaDB Server Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others. Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement. MariaDB [(none)]> create database wpdb; Query OK, 1 row affected (0.08 sec) MariaDB [(none)]> grant all on wpdb.* to ‘wpuser‘@‘localhost‘ identified by ‘wppassword‘; Query OK, 0 rows affected (0.05 sec) MariaDB [(none)]> flush privileges; Query OK, 0 rows affected (0.04 sec) MariaDB [(none)]> exit Bye
(3)网页浏览器中键入http://192.168.1.11/wordpress/，设置注册用户的用户名和密码，完成安装wordPress
4、建立httpd服务器(基于编译的方式进行)，要求：
提供两个基于名称的虚拟主机:
(a)www1.stuX.com，页面文件目录为/web/vhosts/www1；错误日志为/var/log/httpd/www1.err，访问日志为/var/log/httpd/www1.access；
(b)www2.stuX.com，页面文件目录为/web/vhosts/www2；错误日志为/var/log/httpd/www2.err，访问日志为/var/log/httpd/www2.access；
(c)为两个虚拟主机建立各自的主页文件index.html，内容分别为其对应的主机名；
(d)通过www1.stuX.com/server-status输出httpd工作状态相关信息，且只允许提供帐号密码才能访问(status:status)；
1、编译安装httpd请参考第3题
2、编辑配置httpd配置文件注视DocumentRoot并开启vhosts
[root@localhost ~]# vim /etc/httpd24/httpd.conf #DocumentRoot "/usr/local/apache24/htdocs" Include /etc/httpd24/extra/httpd-vhosts.conf
3、创建2个虚拟主机页面文件目录、日志目录，并提供主页文件index.html
[root@localhost ~]# mkdir -pv /web/vhosts/www{1,2}
[root@localhost ~]# mkdir /var/log/httpd/
[root@localhost ~]# echo www1.stu110.com > /web/vhosts/www1/index.html
[root@localhost ~]# echo www2.stu110.com > /web/vhosts/www2/index.html4、编辑vhosts配置文件，创建两个基于名称的虚拟主机，指定相应的日志文件，并设置server-status
[root@localhost ~]# vim /etc/httpd24/extra/httpd-vhosts.conf <VirtualHost *:80> DocumentRoot "/web/vhosts/www1" ServerName www1.stu110.com ErrorLog "/var/log/httpd/www1.err" CustomLog "/var/log/httpd/www1.access" common <Directory "/web/vhosts/www1"> Options None AllowOverride None Require all granted </Directory> <Location /server-status> SetHandler server-status AuthType Basic AuthName "Server Status" AuthUserFile "/etc/httpd24/.htpasswd" Require valid-user </Location> </VirtualHost> <VirtualHost *:80> DocumentRoot "/web/vhosts/www2" ServerName www2.stu110.com ErrorLog "/var/log/httpd/www2.err" CustomLog "/var/log/httpd/www2.access" common <Directory "/web/vhosts/www2"> Options None AllowOverride None Require all granted </Directory> </VirtualHost>
5、生成server-status认证用到的密码文件
[root@localhost ~]# htpasswd -c -m /etc/httpd24/.htpasswd status New password: Re-type new password: Adding password for user status
6、编辑hosts文件，添加主机记录
[root@localhost ~]# vim /etc/hosts 192.168.1.11 www1.stu100.com 192.168.1.11 www2.stu100.com
7、检查配置文件，重启httpd服务并测试
[root@localhost ~]# httpd -t Syntax OK [root@localhost ~]# apachectl restart [root@localhost ~]# curl www1.stu100.com www1.stu110.com [root@localhost ~]# curl www2.stu100.com www2.stu110.com
5、为第4题中的第2个虚拟主机提供https服务，使得用户可以通过https安全的访问此web站点；
(1)要求使用证书认证，证书中要求使用的国家(CN)、州(HA)、城市(ZZ)和组织(MageEdu)；
(2)设置部门为Ops，主机名为www2.stuX.com，邮件为admin@stuX.com；
1、创建私有CA，签署并颁发证书
[root@localhost ~]# cd /etc/pki/CA/ [root@localhost CA]# touch index.txt [root@localhost CA]# echo 01 > serial [root@localhost CA]# (umask 077; openssl genrsa -out /etc/pki/CA/private/cakey.pem 2048) Generating RSA private key, 2048 bit long modulus ..........................................................+++ .................................................................................+++ e is 65537 (0x10001) [root@localhost CA]# openssl req -new -x509 -key /etc/pki/CA/private/cakey.pem -days 365 -out /etc/pki/CA/cacert.pem You are about to be asked to enter information that will be incorporated into your certificate request. What you are about to enter is what is called a Distinguished Name or a DN. There are quite a few fields but you can leave some blank For some fields there will be a default value, If you enter ‘.‘, the field will be left blank. ----- Country Name (2 letter code) [XX]:CN State or Province Name (full name) []:HA Locality Name (eg, city) [Default City]:ZZ Organization Name (eg, company) [Default Company Ltd]:MageEdu Organizational Unit Name (eg, section) []:Ops Common Name (eg, your name or your server‘s hostname) []:www2.stu110.com Email Address []:admin@stu110.com [root@localhost CA]# cd /etc/httpd24/ [root@localhost httpd24]# mkdir ssl [root@localhost httpd24]# cd ssl [root@localhost ssl]# (umask 077;openssl genrsa -out httpd.key 2048) Generating RSA private key, 2048 bit long modulus .....................................+++ ...................................+++ e is 65537 (0x10001) [root@localhost ssl]# openssl req -new -key httpd.key -out httpd.csr You are about to be asked to enter information that will be incorporated into your certificate request. What you are about to enter is what is called a Distinguished Name or a DN. There are quite a few fields but you can leave some blank For some fields there will be a default value, If you enter ‘.‘, the field will be left blank. ----- Country Name (2 letter code) [XX]:CN State or Province Name (full name) []:HA Locality Name (eg, city) [Default City]:ZZ Organization Name (eg, company) [Default Company Ltd]:MageEdu Organizational Unit Name (eg, section) []:Ops Common Name (eg, your name or your server‘s hostname) []:www2.stu110.com Email Address []:admin@stu110.com Please enter the following ‘extra‘ attributes to be sent with your certificate request A challenge password []: An optional company name []: [root@localhost ssl]# openssl ca -in /etc/httpd24/ssl/httpd.csr -out /etc/pki/CA/certs/httpd.crt -days 365 Using configuration from /etc/pki/tls/openssl.cnf Check that the request matches the signature Signature ok Certificate Details: Serial Number: 1 (0x1) Validity Not Before: Sep 23 14:02:30 2017 GMT Not After : Sep 23 14:02:30 2018 GMT Subject: countryName = CN stateOrProvinceName = HA organizationName = MageEdu organizationalUnitName = Ops commonName = www2.stu110.com emailAddress = admin@stu110.com X509v3 extensions: X509v3 Basic Constraints: CA:FALSE Netscape Comment: OpenSSL Generated Certificate X509v3 Subject Key Identifier: F1:62:C9:95:0C:45:BA:BC:83:D7:41:54:F1:5C:93:7B:25:BB:6A:FB X509v3 Authority Key Identifier: keyid:D0:5E:8F:AD:FC:62:2C:0E:46:78:C0:A7:7E:EC:95:7A:80:00:D9:3D Certificate is to be certified until Sep 23 14:02:30 2018 GMT (365 days) Sign the certificate? [y/n]:y 1 out of 1 certificate requests certified, commit? [y/n]y Write out database with 1 new entries Data Base Updated [root@localhost ssl]# cp /etc/pki/CA/certs/httpd.crt /etc/httpd24/ssl/ [root@localhost ssl]# ls httpd.crt httpd.csr httpd.key
2、安装ssl模块，删除www2.stu110.com在httpd-vhosts中的定义，在主配置文件中启用ssl模块，并为www2.stu110.com配置ssl
[root@localhost ~]# yum install -y mod_ssl [root@localhost ~]# vim /etc/httpd24/httpd.conf LoadModule ssl_module modules/mod_ssl.so Include /etc/httpd24/extra/httpd-ssl.conf [root@localhost ~]# vim /etc/httpd24/extra/httpd-ssl.conf Listen 443 SSLPassPhraseDialog builtin <VirtualHost *:443> DocumentRoot "/web/vhosts/www2" ServerName www2.stu110.com:443 ErrorLog "/var/log/httpd/www2.err" CustomLog "/var/log/httpd/www2.access" common SSLEngine on SSLCertificateFile /etc/httpd24/ssl/httpd.crt SSLCertificateKeyFile /etc/httpd24/ssl/httpd.key <Directory "/web/vhosts/www2"> Options None AllowOverride None Require all granted </Directory> </VirtualHost>
3、检查配置文件，重启httpd服务并测试
[root@localhost ~]# httpd -t Syntax OK [root@localhost ~]# apachectl restart
网页浏览器中键入https://www2.stu100.com/
6、在LAMP架构中，请分别以php编译成httpd模块形式和php以fpm工作为独立守护进程的方式来支持httpd，列出详细的过程。
实验环境：CentOS 7.2(192.168.1.11) + httpd-2.4.9 + mariadb-5.5.57 + php-5.4.26
1、编译安装httpd、mariadb参考第3题
2、安装编译php需要用到的软件包
[root@localhost ~]# yum install -y libxml2-devel libmcrypt-devel bzip2-devel
3、下载并解压php-5.4.26
[root@localhost ~]# tar xf php-5.4.26.tar.bz2 [root@localhost ~]# cd php-5.4.26/
4、php编译成httpd模块形式
(1)通过--with-apxs2=/usr/local/apache24/bin/apxs选项，指定将php编译成http的模块形式
[root@localhost php-5.4.26]# ./configure --prefix=/usr/local/php --with-mysql=/usr/local/mysql --with-openssl --with-mysqli=/usr/local/mysql/bin/mysql_config --enable-mbstring --with-png-dir --with-jpeg-dir --with-freetype-dir --with-zlib --with-libxml-dir=/usr --enable-xml --enable-sockets --with-apxs2=/usr/local/apache24/bin/apxs --with-mcrypt --with-config-file-path=/etc --with-config-file-scan-dir=/etc/php.d --with-bz2 [root@localhost php-5.4.26]# make && make install
(2)为php提供配置文件，编辑httpd配置文件使其支持php，并提供php测试页
[root@localhost php-5.4.26]# cp php.ini-production /etc/php.ini [root@localhost php-5.4.26]# vim /etc/httpd24/httpd.conf
添加php文件类型
AddType application/x-httpd-php .php AddType application/x-httpd-php-source .phps DirectoryIndex index.php index.html [root@localhost php-5.4.26]# vim /usr/local/apache24/htdocs/index.php <h1>phptest</h1> <?php phpinfo(); ?>
(3)重启httpd服务，测试php测试页是否能正常访问
[root@localhost php-5.4.26]# apachectl restart
5、php以fpm工作为独立守护进程的方式来支持httpd
(1)通过--enable-fpm选项，指定php以fpm工作为独立守护进程的方式来支持httpd
[root@localhost php-5.4.26]# ./configure --prefix=/usr/local/php --with-mysql=/usr/local/mysql --with-openssl --with-mysqli=/usr/local/mysql/bin/mysql_config --enable-mbstring --with-png-dir --with-jpeg-dir --with-freetype-dir --with-zlib --with-libxml-dir=/usr --enable-xml --enable-sockets --enable-fpm --with-mcrypt --with-config-file-path=/etc --with-config-file-scan-dir=/etc/php.d --with-bz2 [root@localhost php-5.4.26]# make && make install
(2)为php-fpm提供配置文件
[root@localhost php-5.4.26]# cp php.ini-production /etc/php.ini [root@localhost php-5.4.26]# cp /usr/local/php/etc/php-fpm.conf.default /usr/local/php/etc/php-fpm.conf
(3)为php-fpm提供SysV服务
[root@localhost php-5.4.26]# cp sapi/fpm/init.d.php-fpm /etc/rc.d/init.d/php-fpm [root@localhost php-5.4.26]# chmod +x /etc/rc.d/init.d/php-fpm [root@localhost php-5.4.26]# chkconfig --add php-fpm [root@localhost php-5.4.26]# service php-fpm start Starting php-fpm done [root@localhost php-5.4.26]# netstat -antup | grep php-fpm tcp 0 0 127.0.0.1:9000 0.0.0.0:* LISTEN 35116/php-fpm: mast
(4)编辑httpd配置文件使其启用php-fpm模块，并提供php测试页
[root@localhost php-5.4.26]# vim /etc/httpd24/httpd.conf
取消以下2行前的注释
LoadModule proxy_module modules/mod_proxy.so LoadModule proxy_fcgi_module modules/mod_proxy_fcgi.so
添加php文件类型，并使php文件通过fpm访问
AddType application/x-httpd-php .php AddType application/x-httpd-php-source .phps DirectoryIndex index.php index.html ProxyRequests Off ProxyPassMatch ^/(.*\.php)$ fcgi://127.0.0.1:9000/usr/local/apache24/htdocs/$1 [root@localhost php-5.4.26]# vim /usr/local/apache24/htdocs/index.php <h1>phpfpmtest</h1> <?php phpinfo(); ?>
(5)重启httpd服务，测试php测试页是否能正常访问
[root@localhost php-5.4.26]# apachectl restart
标签：http
原文地址：http://941641.blog.51cto.com/931641/1968454
