nginx1.8.1反向代理、负载均衡功能的实现
nginx1.8.1 proxy 服务器192.168.8.40
web1 centos6.5 httpd2.2.15
web2 centos7.2 httpd2.4.6
1、代理功能的简单实现
nginx代理服务器：192.168.8.40
web服务器：192.168.8.101
8.40添加代理：
location /forum/ {
proxy_pass http://192.168.8.101/bbs/;
}
在被代理的web端
创建目录mkdir /web/htdocs/bbs
vim /web/htdocs/bbs/index.html
加入<h1>192.168.8.101 bbs</h1>
访问 http://192.168.8.40/forum/即可出现8.101的内容
改成正则表达式的方式：
location ~* ^/forum {
proxy_pass http://192.168.8.101;
}
此时http://192.168.8.40/forum/的方式不能访问，需要通过修改192.168.8.101的bbs目录改为forum即可访问
# mv bbs forum
2、代理上显示客户端真实IP(方便统计真实的IP访问情况)
8.101上更改显示日志的方式：
# vim /etc/httpd/conf/httpd.conf
LogFormat "%{X-Real-IP}i %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
nginx服务器端8.40配置：
location ~* ^/forum {
proxy_pass http://192.168.8.101;
proxy_set_header X-Real-IP $remote_addr;
}
3.实现简单的负载均衡：
nginx proxy server:192.168.8.40
apache web1:192.168.8.39
apache web2:192.168.8.101
nginx proxy server:192.168.8.40配置：
# 定义web服务器集群：
upstream webservers {
server 192.168.8.39 weight=1;
server 192.168.8.101 weight=1;
}
server {
#location / {
# root /web/htdocs;
# index index.php index.html index.htm;
#}
#定义访问集群
location / {
proxy_pass http://webservers/;
proxy_set_header X-Real-IP $remote_addr;
}
}
通过访问http://192.168.8.40可以看到负载的效果
4、对负载均衡的服务器宕机情况进行适配
#添加错误的定义
server {
listen 8080;
server_name localhost;
root /web/errorpages;
index index.html;
}
# 创建错误页面定义
# mkdir /web/errorpages/ -pv
# vim index.html
加入
sorry,website is being repaired please wait
# 添加超时定义及错误页面定义，如果连续访问错误两次则踢掉，检测时间间隔2秒
upstream webservers {
server 192.168.8.39 weight=1 max_fails=2 fail_timeout=2;
server 192.168.8.101 weight=1 max_fails=2 fail_timeout=2;
server 127.0.0.1:8080 weight=1 backup;
}
测试，关闭web1则，只能访问到web2，关闭web2后出现错误提示
5、为反向代理启用缓存功能
proxy_cache_path /nginx/cache/first levels=1:2 keys_zone=first:20m max_size=1g;
server {
listen 80;
server_name localhost;
index index.html index.php;
add_header X-Via $server_addr;
add_header X-Cache "$upstream_cache_status from $server_addr";
location / {
proxy_pass http://webservers/;
proxy_set_header X-Real-IP $remote_addr;
proxy_cache first;
proxy_cache_valid 200 10m;
}
# nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: [emerg] mkdir() "/nginx/cache/first" failed (2: No such file or directory)
nginx: configuration file /etc/nginx/nginx.conf test failed
[root@centossz008 ~]# mkdir -pv /nginx/cache/first
mkdir: created directory `/nginx'
mkdir: created directory `/nginx/cache'
mkdir: created directory `/nginx/cache/first'
add_header X-Via $server_addr;
add_header X-Cache "$upstream_cache_status from $server_addr";
提示信息如下：
6、重定向规则
location / {
#root html;
root /web/htdocs;
index index.html index.htm;
rewrite ^/bbs/(.*)$ http://192.168.8.101/forum/$1;
}
访问：http://192.168.8.40/bbs/
7、上传文件的负载均衡
可能碰到这样的业务场景，几台web app设置了主从，一个服务器负责上传，其他只能通过同步来获取
nginx配置：
location / {
proxy_pass http://192.168.8.40/;
if ($request_method = "PUT"){
proxy_pass http://192.168.8.101;
}
}
客户端配置：
# vim /etc/httpd/conf/httpd.conf
在<Directory "/web/htdocs">下面添加Dav on
<Directory "/web/htdocs">
Dav on
# curl -T /etc/fstab http://192.168.8.40
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>201 Created</title>
</head><body>
<h1>Created</h1>
<p>Resource /fstab has been created.</p>
</body></html>
在8.101上可以看到上传的文件
htdocs]# ls
forum fstab index.html
8、通过nginx统计某推广链接重写url
需求：
通过nginx统计某推广链接(如：http://www.baidu.com)的访问次数，即访问tuiguang.chinasoft.com自动跳转到www.baidu.com页面
如该服务器为1.1.1.1，带宽要足够大(要根据实际访问量来定)
步骤
①添加1.1.1.1的dns域名解析 tuiguang.chinasoft.com --> 1.1.1.1
②添加相关的配置
vim /etc/nginx/conf.d/tuiguang.conf
server {
server_name tuiguang.chinasoft.com;
rewrite_log on; # 打开重写的日志
error_log /data/logs/app_h5.log notice;
access_log /data/logs/app_error_h5.log;
location /h5/flow{
alias /data/h5;
index index.html;
proxy_set_header Host $host;
proxy_set_header X-Real-Ip $remote_addr;
proxy_set_header X-Forwarded-For $remote_addr;
rewrite ^(.*) http://www.baidu.com break;
}
}
9.修改http头Content-Type为application/octet-stream
upstream lvs_server{
server 10.27.13.215:; #hd_lvs_voice01
server 10.26.114.166:; #hd_lvs_voice02
server 10.27.62.9:; #hd_lvs_voice03
server 10.30.196.175:; #hd_lvs_voice04
server 10.30.196.157:; #hd_lvs_voice05
}
server {
listen ;
location / {
proxy_pass http://lvs_server;
}
location /index {
proxy_set_header Host $http_host;
proxy_set_header X-Real-Ip $remote_addr;
proxy_set_header X-Forwarded-For $remote_addr;
proxy_set_header Content-Type application/octet-stream;
proxy_pass http://lvs_server;
}#end index
}
日志中添加响应时间，请求时间的日志格式
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for" "$http_host" "$upstream_response_time" "$request_time"';
nginx获取不到客户端真实IP地址
upstream dxflowservers {
ip_hash;
server u04flow01.yaya.corp: weight= max_fails= fail_timeout=;
server u04rec02.yaya.corp: weight= max_fails= fail_timeout=;
}
server {
server_name 106.75.19.93;
server_name dxacc.chinasoft.cn;
location /{
root /data/chinasoft/dx_traffic/liuliang_http/liuliangsdk/;
index index.html;
try_files $uri $uri/ /index.html;
}
location /dingxiangsdk/{
proxy_set_header Host $host;
proxy_set_header X-Real-Ip $remote_addr;
# 经过ulb(lvs)以后无法获取客户端的真实IP地址,去掉下面这行即可
#proxy_set_header X-Forwarded-For $remote_addr;
proxy_pass http://dxflowservers/;
}
location /ngx_status {
stub_status on;
access_log off;
allow 127.0.0.1;
#deny all;
}
}
简单测试反向代理upstream的健康检查功能
nginx --> apache(两台)
nginx : 192.168.3.200 (nginx 1.12.2)
apache01: 192.168.3.12
apache02:192.168.3.13
nginx的配置
upstream lvs_server{
server 192.168.3.12: weight= max_fails= fail_timeout=;
server 192.168.3.13: weight= max_fails= fail_timeout=;
}
server {
listen ;
server_name 192.168.3.200;
access_log /var/log/nginx/voice_lvs.access.log main;
error_log /var/log/nginx/voice_lvs.error.log;
location / {
proxy_pass http://lvs_server/;
}
location /index {
proxy_set_header Host $http_host;
proxy_set_header X-Real-Ip $remote_addr;
proxy_set_header X-Forwarded-For $remote_addr;
proxy_set_header Content-Type application/octet-stream;
proxy_pass http://lvs_server;
}
location /ngx_status {
stub_status on;
access_log off;
allow 127.0.0.1;
}
}
[root@centossz008 ~]# cat /var/www/html/index.html
<h1>192.168.3.12</h1>
server01
[root@node5 ~]# cat /var/www/html/index.html
<h1>192.168.3.13</h1>
server02
经过测试，当不配置以下参数，如果关掉其中一台apache，请求会全部到另外一台中，所以upstream默认就会检查后端服务器，如果配置就按照你的配置
不配置就按照默认配置
weight=2 max_fails=5 fail_timeout=6;
[root@localhost /etc/nginx/conf.d]# for i in {1..20}; do curl http://192.168.3.200:8555/index.html;done
重定向示例
# cat /usr/local/nginx/conf/vhost.d/chinasoft.com.conf
map $http_origin $corsHost {
default "none" ;
"~https://chinasoft.com" https://chinasoft.com ;
"~https://chinasoft-com.cdn.ampproject.org" https://chinasoft-com.cdn.ampproject.org ;
"~https://chinasoft.com.amp.cloudflare.com" https://chinasoft.com.amp.cloudflare.com ;
"~https://cdn.ampproject.org" https://cdn.ampproject.org ;
"~https://images.chinasoft.com" https://images.chinasoft.com ;
"~https://my.chinasoft.com" https://my.chinasoft.com ;
"~https://store.chinasoft.com" https://store.chinasoft.com ;
"~https://my.chinasoft.jp" https://my.chinasoft.jp ;
} server {
listen ;
server_name chinasoft.com www.chinasoft.com ori-www.chinasoft.com;
access_log /data/www/logs/nginx_log/access/chinasoft.com_access.log main ;
error_log /data/www/logs/nginx_log/error/chinasoft.com_error.log ;
root /data/www/vhosts/chinasoft.com/httpdocs ;
index index.html index.shtml index.php ;
include rewrite.d/chinasoft.com.conf ;
error_page /.html;
rewrite ^/(.*)$ https://www.chinasoft.com/$1 permanent; #跳转到Https location ~ \.php$ {
fastcgi_pass unix:/tmp/php-cgi.sock;
fastcgi_index index.php;
#fastcgi_param SCRIPT_FILENAME ;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
expires -;
} location / {
include proxy_params;
if (!-d $request_filename){
set $flag $flag;
}
if (!-f $request_filename){
set $flag $flag;
}
if ($flag = ""){
rewrite ^(.*)$ /index.php last;
expires -;
} } } server {
listen ;
ssl on; ssl_certificate cert2016/chinasoft_com.crt;
ssl_certificate_key cert2016/chinasoft_com.key;
ssl_dhparam cert2016/dh_2048.pem; ssl_session_timeout 5m;
ssl_protocols TLSv1 TLSv1. TLSv1.; ssl_ciphers "ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-E
CDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-S
HA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:!AES128-GCM-SHA256:!AES256-GCM-SHA384:!AES128-SHA256:!AES256-SHA256:!AES128-SHA:!AES256-SHA:AES:!CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:ED
H-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA"; ssl_prefer_server_ciphers on;
# add_header Strict-Transport-Security max-age=; #ssl_stapling on;
#ssl_stapling_verify on; server_name chinasoft.com www.chinasoft.com ori-www.chinasoft.com ;
access_log /data/www/logs/nginx_log/access/chinasoft.com_access.log main ;
error_log /data/www/logs/nginx_log/error/chinasoft.com_error.log ; root /data/www/vhosts/chinasoft.com/httpdocs ;
index index.html index.shtml index.php ;
include rewrite.d/chinasoft.com.conf ; error_page /.html; #add_header 'Access-Control-Allow-Origin' '*'; add_header Access-Control-Allow-Origin $corsHost;
add_header Access-Control-Allow-Methods 'GET, POST, OPTIONS';
add_header Access-Control-Allow-Headers 'DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Authorization'; location ~ \.php$ {
try_files $uri =;
fastcgi_pass unix:/tmp/php-cgi.sock;
fastcgi_index index.php;
#fastcgi_param SCRIPT_FILENAME ;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
expires -;
} location / {
include proxy_params;
if (!-d $request_filename){
set $flag $flag;
}
if (!-f $request_filename){
set $flag $flag;
}
if ($flag = ""){
rewrite ^(.*)$ /index.php last ;
expires -;
}
} } ***************** if ($request_uri ~ ^/snapchat/snapchat-password-cracker.html) { rewrite ^ https://www.centos.net/snapchat/snapchat-password-cracker.html permanent; }
if ($request_uri ~ ^/spy/index.html) { rewrite ^ https://www.chinasoft.com/topic/index.html permanent; }
if ($request_uri ~ ^/telegram/index.html) { rewrite ^ https://www.chinasoft.com/topic/index.html permanent; }
if ($request_uri ~ ^/track/hidden-phone-tracker-for-android-iphone.html) { rewrite ^ https://www.centos.net/track/hidden-phone-tracker-for-android-iphone.html permanent; }
if ($request_uri ~ ^/viber/index.html) { rewrite ^ https://www.chinasoft.com/topic/index.html permanent; }
[root@EOP_Aimersoft_web01:~]# head - /usr/local/nginx/conf/rewrite.d/chinasoft.com.conf
if ($host ~* ^chinasoft.com$){ rewrite ^(.*)$ http://www.chinasoft.com$1 permanent;}
if ($request_uri ~ ^/(.*)/(index|indice).(html)) { rewrite ^/(.*)/(index|indice).(html) /$ permanent;}
if ($request_uri ~ ^/(index|indice).html) { rewrite ^ / permanent;}
#
if ($request_uri ~ ^/install-chinasoft-spy-app-on-android-phones.html) { rewrite ^ /how-to-spy-android-phones.html permanent; }
配置列出文件列表示例
[root@web:/usr/local/nginx/conf]# more admin_vhost.d/rewrite.chinasoft.cn.conf
server {
listen ;
server_name rewrite.chinasoft.cn ;
access_log /data/www/logs/nginx_log/access/rewrite.chinasoft.cn_access.log main ;
error_log /data/www/logs/nginx_log/error/rewrite.chinasoft.cn_error.log ;
root /usr/local/nginx/conf/rewrite.d ;
#index index.html index.shtml index.php ; error_page /.html;
autoindex on;
location ~ \.php$ {
proxy_pass http://php_pool;
include proxy_params;
access_log off;
} } [root@web:/usr/local/nginx/conf]# more nginx.conf
#user nobody;
worker_processes ; #error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info; #pid logs/nginx.pid;
pid /data/www/logs/nginx.pid; worker_rlimit_nofile ; events {
use epoll;
worker_connections ;
accept_mutex off;
} http {
include mime.types;
default_type application/octet-stream;
#set_real_ip_from 0.0.0.0/;
#real_ip_header X-Forwarded-For; #proxy_set_header Host $host;
#proxy_set_header X-Real-IP $remote_addr;
#proxy_set_header X-Forwarded-For $http_x_forwarded_for;
#proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_headers_hash_max_size ;
proxy_headers_hash_bucket_size ; ssl_session_cache shared:SSL:200m;
ssl_session_timeout 15m; lua_package_path "/usr/local/nginx/conf/ngx_lua_waf/?.lua";
lua_shared_dict limit 10m;
init_by_lua_file /usr/local/nginx/conf/ngx_lua_waf/init.lua;
access_by_lua_file /usr/local/nginx/conf/ngx_lua_waf/waf.lua; #log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';
# log_format main '[$time_local] $remote_addr $status $request_time $body_bytes_sent "$request" "$http_referer" $upstream_addr $http_x_real_ip $http_x_forwarded_for $http_user_agent $request_filename';
log_format main '$remote_addr - - [$time_local] - - "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" "$http_cookie" "$request_body" "$http_user_agent" $request_time ';
# log_format test '[$fastcgi_script_name] [$time_local] $remote_addr $status $request_time $body_bytes_sent "$request" "$http_referer" $upstream_addr $http_x_real_ip $http_x_forwarded_for $http_user_agent ';
log_format error '$remote_addr - - [$time_local] - - "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" $request_time ';
#access_log logs/access.log main; sendfile on;
tcp_nodelay on; keepalive_timeout ;
#----for upload file
client_max_body_size 8M;
client_body_buffer_size 2M;
#--- for resolve error
client_header_buffer_size 64k;
large_client_header_buffers 64k;
proxy_connect_timeout 90s;
proxy_read_timeout 90s;
#60s内后端服务器需要返回成功
proxy_send_timeout 90s;
proxy_buffer_size 16k;
proxy_buffers 32k;
proxy_busy_buffers_size 64k;
proxy_temp_file_write_size 64k;
proxy_ignore_client_abort on;
proxy_intercept_errors on;
gzip on;
gzip_vary off;
gzip_min_length 1k;
gzip_buffers 16k;
gzip_http_version 1.0;
gzip_comp_level ;
gzip_disable "MSIE [1-6]\.";
gzip_types text/plain text/css text/javascript application/javascript application/x-javascript text/xml application/xml application/wasm; ssi on;
ssi_silent_errors on;
#ssi_types text/shtml;
expires 60d;
server_names_hash_bucket_size ;
#if_modified_since before;
#limit_req_zone $binary_remote_addr zone=all_zone:10m rate=3r/s;
#limit_req zone=all_zone burst= nodelay; upstream php_pool{
ip_hash;
#server 192.168.254.122: max_fails= fail_timeout=30s weight=;
#server 192.168.254.123: max_fails= fail_timeout=30s weight=;
#server 192.168.254.124: max_fails= fail_timeout=30s weight=;
#server 192.168.254.125: max_fails= fail_timeout=30s weight=;
server 192.168.254.11: max_fails= fail_timeout=30s weight=; check interval= rise= fall= timeout= type=tcp port=;
check_keepalive_requests ;
# check_http_send "HEAD / HTTP/1.1\r\nConnection: keep-alive\r\n\r\n";
check_http_expect_alive http_2xx http_3xx;
} include vhost.d/*.conf;
include admin_vhost.d/*.conf; server {
listen 80 default_server;
server_name localhost; #charset koi8-r; #access_log logs/host.access.log main; location / {
root /data/www/html;
index index.html index.htm;
} #error_page 404 /404.html; # redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
} location /ws_status {
stub_status on;
access_log off;
} location /status {
check_status html; access_log off;
allow 127.0.0.1;
deny all;
} }
}
nginx1.8.1反向代理、负载均衡功能的实现的更多相关文章
- 十.nginx反向代理负载均衡服务实践部署
期中集群架构-第十章-nginx反向代理负载均衡章节章节====================================================================== 0 ...
- Nginx 反向代理 负载均衡 虚拟主机配置
Nginx 反向代理 负载均衡 虚拟主机配置 通过本章你将学会利用Nginx配置多台虚拟主机,清楚代理服务器的作用,区分正向代理和反向代理的区别,搭建使用Nginx反向搭理和负载均衡,了解Nginx常 ...
- Nginx 反向代理 负载均衡 虚拟主机
Nginx 反向代理 负载均衡 虚拟主机配置 通过本章你将学会利用Nginx配置多台虚拟主机,清楚代理服务器的作用,区分正向代理和反向代理的区别,搭建使用Nginx反向搭理和负载均衡,了解Nginx常 ...
- 【转】Nginx 反向代理 负载均衡 虚拟主机配置
原文:http://www.cnblogs.com/itdragon/p/8059000.html Nginx 反向代理 负载均衡 虚拟主机配置 通过本章你将学会利用Nginx配置多台虚拟主机,清楚代 ...
- 项目实战2.2—nginx 反向代理负载均衡、动静分离和缓存的实现
实验一:实现反向代理负载均衡且动静分离 1.环境准备: 机器名称 IP配置 服务角色 备注 nginx VIP:172.17.11.11 反向代理服务器 开启代理功能 设置监控,调度 rs01 RIP ...
- nginx 详解反向代理负载均衡
什么是反向代理负载均衡 使用代理服务器可以将请求转发给内部的Web服务器,使用这种加速模式显然可以提升静态网页的访问速度.因此也可以考虑使用这种技术,让代理服务器将请求 均匀转发给多台内部Web服务器 ...
- 项目实战2.1—nginx 反向代理负载均衡、动静分离和缓存的实现
总项目流程图,详见 http://www.cnblogs.com/along21/p/8000812.html 实验一:实现反向代理负载均衡且动静分离 1.环境准备: 机器名称 IP配置 服务角色 备 ...
- 项目实战02：nginx 反向代理负载均衡、动静分离和缓存的实现
目录 实验一:实现反向代理负载均衡且动静分离 1.环境准备: 2.下载编译安装tengine 3.设置代理服务器的配置文件 4.启动tengine服务 5.开启后端的web服务 6.测试 实验二:ng ...
- 反向代理负载均衡之APACHE
反向代理负载均衡之APACHE 一.反向代理1.1 介绍反响代理 反向代理(Reverse Proxy)方式是指以代理服务器来接受internet上的连接请求,然后将请求转发给内部网络上的服务器,并将 ...
- Nginx特性验证-反向代理/负载均衡/页面缓存/URL重定向
原文发表于cu:2016-08-25 参考文档: Nginx 反向代理.负载均衡.页面缓存.URL重写等:http://freeloda.blog.51cto.com/2033581/1288553 ...
随机推荐
- javascript调用Flash里对象的方法(函数)搞了五个小时。
搞了几个小时后,才发现,之前走的路是错的. 今天在Firefox浏览器上测试一个javascript调用Flash中的一个对象的方法时遇到问题了, 一搞就整整搞了一个下午. 我记得之前我用Flash8 ...
- spring对事务的配置
接下来我将给大家介绍spring事务配置的两种方式: 1.基于XML的事务配置.2.基于注解方式的事务配置. 前言:在我们详细介绍spring的两种声明式事务管理之前,我们需要先理解这些概念 1)sp ...
- 2018.9青岛网络预选赛(H)
传送门:Problem H https://www.cnblogs.com/violet-acmer/p/9664805.html 题意: BaoBao在一条有刻度的路上行走(哈哈,搞笑),范围为 [ ...
- (reverse)Palindromes hdu2163
Palindromes 链接:http://acm.hdu.edu.cn/showproblem.php?pid=2163 (此题是为了对于JAVA温故知新的) Problem Description ...
- Makefile ------ := ?= += =的区别
Makefile 中:= ?= += =的区别 新建一个Makefile,内容为: ifdef DEFINE_VRE VRE = “Hello World!” endif ifeq ($(OPT),d ...
- 用 Vue 开发一个简单的答题应用（一）
Vue 之类的 MVVM 框架,能帮助我们用更少的代码实现复杂的业务. 为了简单一点,开发计划分成三阶段: 一,数据写死,实现基本的答题效果.支持多种题型. 二,使用本地存储保存数据,支持题目录入的功 ...
- Multi-Nim游戏结论不变证明
Nim取石子游戏结论: 若n堆石子的异或和为0,则先手必胜:否则,先手必败 加入新规则: 每次取完石子后,可以将取的那一堆的石子 分为多堆,也可以不分 结论: 同Nim取石子游戏结论 证明: 如果异或 ...
- 常用关于Android活动的实践技巧
//知晓当前是在哪一个活动 /* 新建一个BaseActivity类(Java class), 继承自AppCompatActivity * 重写 onCreate()方法,已有的活动无需再继承自Ap ...
- A + B,末k位不相同
题目描述 读入两个小于10000的正整数A和B,计算A+B.需要注意的是:如果A和B的末尾K(不超过8)位数字相同,请直接输出-1. 输入描述: 测试输入包含若干测试用例,每个测试用例占一行,格式为& ...
- VS Sln图标空白修复办法
环境:Win10,VS2017,曾经安装并卸载过VS2015之前安装了两个版本的VisualStudio,卸载一个后,就出现了图标空白问题,重新设置默认打开程序也没有作用,经摸索解决办法如下.(1)在 ...