04JavaServlet-25. 设置响应消息头的使用

https://blog.csdn.net/shentian885/article/details/108541881

//添加头部信息
resp<span class="token punctuation">.</span><span class="token function">addHeader</span><span class="token punctuation">(</span><span class="token string">"名字"</span><span class="token punctuation">,</span><span class="token string">"值"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token comment">//添加该名字与值</span>
<span class="token keyword">boolean</span> falg <span class="token operator">=</span> resp<span class="token punctuation">.</span><span class="token function">containsHeader</span><span class="token punctuation">(</span><span class="token string">"名字"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token comment">//查询响应头中是否包含某个名字，存在返回true，否则返回 false</span>

//添加响应头时，名字可以随便取，但是一般使用常见的名字
<span class="token comment">//Server -&gt; tomcat版本</span>

<span class="token comment">//Date -&gt; 时间</span>
    resp<span class="token punctuation">.</span><span class="token function">setDateHeader</span><span class="token punctuation">(</span><span class="token string">"Date"</span><span class="token punctuation">,</span><span class="token keyword">long</span><span class="token operator">-</span>时间的毫秒数<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token comment">//与resp.addHeader("Date","值")效果相同</span>

<span class="token comment">//Content-Type -&gt; 响应返回的内容类型 </span>
    resp<span class="token punctuation">.</span><span class="token function">setContentType</span><span class="token punctuation">(</span><span class="token string">"text/html;charset=utf-8"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token comment">//与resp.addHeader("Content-Type","text/html;charset=utf-8")效果相同</span>

<span class="token comment">//Location -&gt; 302时，返回请求资源的新路径</span>

<span class="token comment">//Content-Encoding -&gt; 服务端能够发送压缩编码类型</span>
     resp<span class="token punctuation">.</span><span class="token function">addHeader</span><span class="token punctuation">(</span><span class="token string">"Content-Encoding"</span><span class="token punctuation">,</span><span class="token string">"gzip"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">//Content-Length -&gt; 服务器发送的压缩数据的长度</span>
    resp<span class="token punctuation">.</span><span class="token function">addHeader</span><span class="token punctuation">(</span><span class="token string">"Content-Length"</span><span class="token punctuation">,</span><span class="token string">"长度"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">//Content-language -&gt; 服务器发送的语言类型</span>
    resp<span class="token punctuation">.</span><span class="token function">addHeader</span><span class="token punctuation">(</span><span class="token string">"Content-Language"</span><span class="token punctuation">,</span><span class="token string">"zh-cn"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">//Last-Modified -&gt; 服务端对该资源最后的修改时间</span>
    resp<span class="token punctuation">.</span><span class="token function">addHeader</span><span class="token punctuation">(</span><span class="token string">"Last-Modifies"</span><span class="token punctuation">,</span><span class="token keyword">new</span> <span class="token class-name">Date</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">//Content-Disposition -&gt; 服务器要求客户端以下载文件的方式打开该文件</span>
    resp<span class="token punctuation">.</span><span class="token function">addHeader</span><span class="token punctuation">(</span><span class="token string">"Content-Disposition"</span><span class="token punctuation">,</span><span class="token string">"attachment;filename=下载文件名.后缀名"</span><span class="token punctuation">)</span>

<span class="token comment">//设置浏览器是否缓存</span>
    resp<span class="token punctuation">.</span><span class="token function">addHeader</span><span class="token punctuation">(</span><span class="token string">"Expires"</span><span class="token punctuation">,</span><span class="token string">"-1"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    resp<span class="token punctuation">.</span><span class="token function">addHeader</span><span class="token punctuation">(</span><span class="token string">"Cache-Control"</span><span class="token punctuation">,</span><span class="token string">"no-cache"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    resp<span class="token punctuation">.</span><span class="token function">addHeader</span><span class="token punctuation">(</span><span class="token string">"Pragma"</span><span class="token punctuation">,</span><span class="token string">"no-cache"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token comment">//针对不同浏览器的兼容</span>

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