關於 NSURL 的解析和編碼

NSURL毫無疑問是常用類，有時候我們需要對一個url進行分析整理，當然是可以按照RFC 1808的定義去自己分析，但是萬能的Apple大大已經在SDK裡扔了不少方法來幫助解析一個url了…方便又快捷吶～比如下面的輸入：

<code class="hljs objectivec"><span class="hljs-built_in">NSURL</span> *url = [<span class="hljs-built_in">NSURL</span> URLWithString:  
 <span class="hljs-string">@"http://www.onevcat.com/2011/11/debug/;param?p=307#more-307"</span>];
<span class="hljs-built_in">NSLog</span>(@“Scheme: %@”, [url scheme]);  
<span class="hljs-built_in">NSLog</span>(@“Host: %@”, [url host]);  
<span class="hljs-built_in">NSLog</span>(@“Port: %@”, [url port]);  
<span class="hljs-built_in">NSLog</span>(@“Path: %@”, [url path]);  
<span class="hljs-built_in">NSLog</span>(@“Relative path: %@”, [url relativePath]);  
<span class="hljs-built_in">NSLog</span>(@“Path components as array: %@”, [url pathComponents]);  
<span class="hljs-built_in">NSLog</span>(@“Parameter string: %@”, [url parameterString]);  
<span class="hljs-built_in">NSLog</span>(@“Query: %@”, [url query]);  
<span class="hljs-built_in">NSLog</span>(@“Fragment: %@”, [url fragment]);  
</code>

將得到以下輸出：

關於 NSURL 的解析和編碼

沒什麼值得多說的～相當方便就能得到所要結果的方法～另外，在由NSString生成NSURL對象時，有可能會出現NSString中包含百分號各類括號冒號等對於url來說的非法字符如果直接進行轉換的話將得到nil。在對於復雜url進行轉換前，可以先試試對待轉換的NSString發送 stringByAddingPercentEscapesUsingEncoding: 將其轉換為合法的url字符串（其實目的就是保證非法字符用UTF8編碼..）比如這樣：

<code class="hljs objectivec"><span class="hljs-built_in">NSString</span> *fixedStr = [reqStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];  
</code>