如何從標題獲取最後修改日期字符串

Question

我已經在標題對象中獲得了標題值。但我需要將「Last-Modified」放入字符串對象中進行比較。請你能告訴我應該如何將最後一個標題放入字符串中。

HttpClient client = new DefaultHttpClient(); 
//HttpGet get = new HttpGet(url); 
HttpHead method = new HttpHead(url); 
HttpResponse response = client.execute(method); 
Header[] s = response.getAllHeaders(); 

String sh = String.valueOf(s); 
System.out.println("The value of sh:"+sh); 

System.out.println("The header from the httpclient:"); 

for (int i = 0; i < s.length; i++) { 
    Header hd = s[i]; 
    System.out.println("Header Name: "+hd.getName() + "  " + " Header Value: " + hd.getValue()); 
} 

String last-modified = // here I need to convert this header(last-modified); 

Answer 1

嘗試是這樣的：

Header[] s = response.getHeaders("last-modified"); 
String lastModified = s[0].getValue(); // ! There might be more than 1 header 
             // ! or none at all 

Answer 2

在很多情況下，你得到的只是一個Last-Modified頭，所以你可以簡單地使用：

String lastModified = response.getHeader("last-modified"); 
if (lastModified != null) { // in case the header isn't set 
    // do something 
} 

對於多個值，則JavaDoc說：如果具有給定名稱的響應頭存在且包含多個值，則會返回首先添加的值。

Answer 3

private String getLastModifiedDate(HttpResponse response) { 
    Header header = response.getFirstHeader("Date"); 
    if (header != null) { 
     return header.getValue(); 
    } 

    return ""; 
}