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wentch
2016-01-17 11:50:10 +08:00
parent 27badfa735
commit 4f640fb0a6

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@@ -26,7 +26,7 @@
<section class="main-content">
<h3><a id="convert_intro" class="anchor" href="#" aria-hidden="true"><span class="octicon octicon-link"></span></a>Convert 组件介绍</h3>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Convert 是一个比较独立的组件仅依赖于util包。提供Java对象的序列化与反解析功能。支持JSON(JavaScript Object Notation)、BSON(Binary Stream Object Notation)两种格式化。 两种格式使用方式完全一样其性能都大幅度超过其他JSON框架。同时JSON内置于HTTP协议BSON也是SNCP协议数据序列化的基础。<br/></p>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Convert 是一个比较独立的组件仅依赖于util包。提供Java对象的序列化与反解析功能。支持JSON(JavaScript Object Notation)、BSON(Binary Stream Object Notation)两种格式化。 两种格式使用方式完全一样其性能都大幅度超过其他JSON框架。同时JSON内置于HTTP服务BSON也是SNCP协议数据序列化的基础。<br/></p>
<h3><a id="convert_study" class="anchor" href="#" aria-hidden="true"><span class="octicon octicon-link"></span></a>Convert 快速上手</h3>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;本介绍仅以JSON为例(BSON与JSON使用方式雷同)。其操作类主要是JsonConvert配置类主要是JsonFactory、ConvertColumn。JsonFactory采用同ClassLoader类似的双亲委托方式设计。</br></p>
@@ -69,7 +69,7 @@
<span class="n">resp</span><span class="o">.</span><span class="na">setContentType</span><span class="o">(</span><span class="s">&quot;text/json; charset=UTF-8&quot;</span><span class="o">);</span>
<span class="n">resp</span><span class="o">.</span><span class="na">getOutputStream</span><span class="o">().</span><span class="na">write</span><span class="o">(</span><span class="n">json</span><span class="o">.</span><span class="na">getBytes</span><span class="o">(</span><span class="s">&quot;UTF-8&quot;</span><span class="o">));</span>
<span class="o">}</span></pre></div>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;几乎所有的JSON框架提供的接口以String作为返回结果为主其内在都是以char[]作为JsonWriter的载体。以Gson为例Gson拼接JSON默认使用的是StringWriterStringWriter的扩容策略是翻倍。为了方便计算假设一个对象转换成JSON字符串大小为了10K。Gson在转换过程中产生的临时的char[]的大小: 16 + 32 + 64 + 128 + 256 + 512 + 1K + 2K + 4K + 8K + 16K = 32K, char[]转换成最终的String结果又会产生10K的char[], 最后在response输出时又产生10K的byte[](方便计算不考虑双字节),也就是说整个对象输出过程中会产生52K的临时数据。而且常见的HTTP服务器(如实现java-servlet规范的服务器)不会把底层的ByteBuffer对象池暴露给上层。所以以String为输出结果的JSON方法都会产生5倍于数据体积大小(其他低于1倍扩容策略的框架会产生更多)的垃圾数据。<br/>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;几乎所有的JSON框架提供的接口以String作为返回结果为主其内在都是以char[]作为JsonWriter的载体。以Gson为例Gson拼接JSON默认使用的是StringWriterStringWriter的扩容策略是翻倍。为了方便计算假设一个对象转换成JSON字符串大小为了10K。Gson在转换过程中产生的临时的char[]的大小: 16 + 32 + 64 + 128 + 256 + 512 + 1K + 2K + 4K + 8K + 16K = 32K, char[]转换成最终的String结果又会产生10K的char[], 最后在response输出时又产生10K的byte[](方便计算不考虑双字节),也就是说整个对象输出过程中会产生52K的临时数据。而且常见的HTTP服务器(如实现java-servlet规范的服务器)不会把底层的ByteBuffer对象池暴露给上层。所以以String为输出结果的JSON方法都会产生5倍于数据体积大小(其他低于1倍扩容策略的框架会产生更多)的垃圾数据。<br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;RedKale框架的HTTP服务内置了Convert的JSON接口避免了大量的垃圾数据产生。RedKale的HTTP是基于AIO(NIO.2)实现且存在ByteBuffer对象池response的finishJson系列方法将HTTP服务的ByteBuffer对象池传给Convert 使Convert在序列化过程中直接以UTF-8编码方式输出到ByteBuffer里输出结束后将ByteBuffer交给对象池回收从而减少大量构建bye[]、char[]所产生的临时数据。</p>
<div class="highlight"><pre> <span class="kd">protected</span> <span class="kt">void</span> <span class="nf">execute</span><span class="o">(</span><span class="n">HttpRequest</span> <span class="n">req</span><span class="o">,</span> <span class="n">HttpResponse</span> <span class="n">resp</span><span class="o">)</span> <span class="kd">throws</span> <span class="n">IOException</span> <span class="o">{</span>
<span class="n">resp</span><span class="o">.</span><span class="na">finishJson</span><span class="o">(</span><span class="n">record</span><span class="o">);</span>
@@ -221,7 +221,7 @@
<span class="kd">public</span> <span class="kt">void</span> <span class="nf">mydetail</span><span class="o">(</span><span class="n">HttpRequest</span> <span class="n">req</span><span class="o">,</span> <span class="n">HttpResponse</span> <span class="n">resp</span><span class="o">)</span> <span class="kd">throws</span> <span class="n">IOException</span> <span class="o">{</span>
<span class="kt">int</span> <span class="n">userid</span> <span class="o">=</span> <span class="n">currentUser</span><span class="o">(</span><span class="n">req</span><span class="o">).</span><span class="na">getUserid</span><span class="o">();</span> <span class="c1">//获取当前用户ID</span>
<span class="n">UserSimpleInfo</span> <span class="n">user</span> <span class="o">=</span> <span class="n">service</span><span class="o">.</span><span class="na">findUserInfo</span><span class="o">(</span><span class="n">userid</span><span class="o">);</span>
<span class="n">resp</span><span class="o">.</span><span class="na">finishJson</span><span class="o">(</span><span class="n">detailConvert</span><span class="o">,</span> <span class="n">req</span><span class="o">);</span> <span class="c1">// 包含用户的注册时间和注册地址字段信息</span>
<span class="n">resp</span><span class="o">.</span><span class="na">finishJson</span><span class="o">(</span><span class="n">detailConvert</span><span class="o">,</span> <span class="n">user</span><span class="o">);</span> <span class="c1">// 包含用户的注册时间和注册地址字段信息</span>
<span class="o">}</span>
<span class="o">}</span>
</pre></div>