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json = '["a", "B", "C"]' puts "Unsafe #{unsafe_json (json).inspect}" #输出Unsafe [ "a" , "B" , "C" ] |
Ruby解析Json把上面的json字符串解析成Array。这样的方法并不安全,比如:
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json = 'puts "Danger Will Robinson"' puts "Unsafe #{unsafe_json (json).inspect}" |
又该输出什么呢?很遗憾,解析不出什么东西,跳出一个警告:warning: character class has `[' without escape安全的方法如下:
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module SafeJSON require 'monitor' def SafeJSON.build_safe_json ret = nil waiter = '' waiter.extend(MonitorMixin) wait_cond = waiter.new_cond Thread .start do $SAFE = 4 ret = Proc . new {|json| eval(json.gsub(/(["'])/s*:/s* ([' "0-9tfn/[{])/){" #{$1}=>#{$2}"}) } waiter.synchronize do wait_cond.signal end end waiter.synchronize do wait_ cond.wait_while { ret. nil ? } end return ret end @@parser = SafeJSON.build_safe_json # Safely parse the JSON input def SafeJSON.parse(input) @@parser .call(input) rescue SecurityError return nil end end |
包含这个Module,你就可以这样使用Ruby解析Json:
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peoples=SafeJSON.parse(' { "peoples" :[{ "name" : "site120" ," email ":" site120 @163 .com "," sex ":" 男"}, { "name" : "site120_2" , "email" :"site1 20 @163 .com_2 "," sex ":" 男 _2 "}]}') puts peoples[ "peoples" ][ 1 ][ "name" ] #输出site120_2 |
Ruby on Rails中
rails通过RJS内置了对AJAX的支持,也许用到json的机会并不多,不过作为一种数据交换的方便格式,还是值的注意,下面
这里使用到Json插件,安装命令
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gem install json_pure |
使用例子:
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require "open-uri" require 'json' def index uri = '*****' response = nil begin open(uri) do |http| response = http.read end @json = JSON : :parse (response) rescue => text # 异常处理 logger.error( "GetMailListserror=" + text) flash.now[ :error ] = '获取邮件列表失败。' end end |
这里json解析器需要json格式的key必须带引号,如果没有引号的话会解析出现异常。