在下图中，我想要网页的总响应时间。我似乎无法在文件sample HAR file 中找到它，即在这种情况下为 38.79s。有谁知道如何获得这个？
我将使用 Selenium 以及 Firebug 和 NetExport 来导出 HAR 文件，但现在我正在尝试手动执行此操作。添加单个响应不会给出正确的数字。
在某个时候，我想要一个 Java 程序来查找并提取总响应时间。
【问题讨论】：
标签： javascript firebug page-load-time har
根据上面的输入
import edu.umass.cs.benchlab.har.*;
import edu.umass.cs.benchlab.har.tools.*;
import java.io.File;
import java.io.*;
import java.util.List;
import org.codehaus.jackson.JsonParseException;
public class ParseHarFile {
public static void main(String[] args) {
String fileName = "test.har";
ReadHarFile(fileName);
}
public static void ReadHarFile(String fileName){
File f = new File(fileName);
HarFileReader r = new HarFileReader();
try
{
System.out.println("Reading " + fileName);
HarLog log = r.readHarFile(f);
// Access all pages elements as an object
HarPages pages = log.getPages();
long startTime = pages.getPages().get(0).getStartedDateTime().getTime();
System.out.println("page start time: " + startTime);
// Access all entries elements as an object
HarEntries entries = log.getEntries();
List<HarEntry> hentry = entries.getEntries();
long loadTime = 0;
long responseSize=0;
int entryIndex = 0;
//Output "response" code of entries.
for (HarEntry entry : hentry)
{
System.out.println("entry: " + entryIndex);
System.out.println("request code: " + entry.getRequest().getMethod()); //Output request type
System.out.println("request url: "
+ entry.getRequest().getUrl()); //Output request Url
System.out.println(" start time: " + entry.getStartedDateTime().getTime()); // Output start time
System.out.println(" time: " + entry.getTime()); // Output start time
System.out.println("response code: "
+ entry.getResponse().getStatus()); //Output response code
responseSize=entry.getResponse().getHeadersSize()+entry.getResponse().getBodySize();
System.out.println("response size: "
+ responseSize); //Output response size
long entryLoadTime = entry.getStartedDateTime().getTime() + entry.getTime();
if(entryLoadTime > loadTime){
loadTime = entryLoadTime;
}
System.out.println();
entryIndex++;
}
long loadTimeSpan = loadTime - startTime;
System.out.println("loadTimeSpan: " + loadTimeSpan);
Double webLoadTime = ((double)loadTimeSpan) / 1000;
double webLoadTimeInSeconds = Math.round(webLoadTime * 100.0) / 100.0;
System.out.println("Web Load Time: " + webLoadTimeInSeconds) ;
}
catch (JsonParseException e)
{
e.printStackTrace();
System.out.println("Parsing error during test");
}
catch (IOException e)
{
e.printStackTrace();
System.out.println("IO exception during test");
}
}
}
【讨论】：
这是一个返回页面加载时间的 Java 函数。此外，它还允许您解析缺少元素或其他违反规范的损坏的 HAR 文件。更多信息。在 HarLib here。
public long calculatePageLoadTime(String filename) {
File file = new File("c:\\" + filename);
HarFileReader fileReader = new HarFileReader();
long pageLoadTime = 0;
try {
//Catch missing elements or other violations to HAR specification.
//You can still read most of a file even if some parts are corrupted.
List<HarWarning> warnings = new ArrayList<HarWarning>();
HarLog log = fileReader.readHarFile(file, warnings);
for (HarWarning warning : warnings)
System.out.println("File:" + filename + " - Warning:" + warning);
//Get page load start time
HarPages pages = log.getPages();
HarPage page = pages.getPages().get(0);
long startTime = page.getStartedDateTime().getTime();
//Traverse entries and determine the latest request end time
long loadTime = 0;
HarEntries entries = log.getEntries();
List<HarEntry> entryList = entries.getEntries();
for (HarEntry entry : entryList)
{
long entryLoadTime = entry.getStartedDateTime().getTime() + entry.getTime();
if(entryLoadTime > loadTime){
loadTime = entryLoadTime;
}
}
pageLoadTime = loadTime - startTime;
}
catch (JsonParseException e)
{
e.printStackTrace();
System.out.println("Parsing error during test");
}
catch (IOException e)
{
e.printStackTrace();
System.out.println("IO exception during test");
}
return pageLoadTime;
}
【讨论】：
根据@Sebastian Zartner 的回答和Google sample，以下是Java 尝试：
public class ParseHarFile {
public static void main(String[] args) {
String fileName = "www.google.com.har";
ReadHarFile(fileName);
}
public static void ReadHarFile(String fileName){
File f = new File("C:\\Users\\Administrator\\Desktop\\test_files\\" + fileName);
HarFileReader r = new HarFileReader();
try
{
System.out.println("Reading " + fileName);
HarLog log = r.readHarFile(f);
// Access all pages elements as an object
HarPages pages = log.getPages();
long startTime = pages.getPages().get(0).getStartedDateTime().getTime();
System.out.println("page start time: " + startTime);
// Access all entries elements as an object
HarEntries entries = log.getEntries();
List<HarEntry> hentry = entries.getEntries();
long loadTime = 0;
int entryIndex = 0;
//Output "response" code of entries.
for (HarEntry entry : hentry)
{
System.out.println("entry: " + entryIndex);
System.out.println("request code: " + entry.getRequest().getMethod()); //Output request type
System.out.println(" start time: " + entry.getStartedDateTime().getTime()); // Output start time
System.out.println(" time: " + entry.getTime()); // Output start time
long entryLoadTime = entry.getStartedDateTime().getTime() + entry.getTime();
if(entryLoadTime > loadTime){
loadTime = entryLoadTime;
}
System.out.println();
entryIndex++;
}
long loadTimeSpan = loadTime - startTime;
System.out.println("loadTimeSpan: " + loadTimeSpan);
Double webLoadTime = ((double)loadTimeSpan) / 1000;
double webLoadTimeInSeconds = Math.round(webLoadTime * 100.0) / 100.0;
System.out.println("Web Load Time: " + webLoadTimeInSeconds) ;
}
catch (JsonParseException e)
{
e.printStackTrace();
System.out.println("Parsing error during test");
}
catch (IOException e)
{
e.printStackTrace();
System.out.println("IO exception during test");
}
}
}
【讨论】：
HarFileReader 课程。
总加载时间不是通过汇总所有请求时间而是通过最近的请求结束时间来计算的。从图形上讲，它是在最右边结束的请求栏的右端。在您的示例屏幕截图中，它是最后一个、倒数第三个或倒数第四个请求。
请求结束时间由请求的startedDateTime 属性指示的请求开始时间加上响应所需的时间跨度计算得出，响应时间跨度可通过每个请求的time 属性获得。
要获取最大请求结束时间，您需要遍历所有请求并比较每个请求的结束时间。见以下代码：
var startTime = new Date(har.log.pages[0].startedDateTime);
var loadTime = 0;
// Loop over all entries to determine the latest request end time
// The variable 'har' contains the JSON of the HAR file
har.log.entries.forEach(function(entry) {
var entryLoadTime = new Date(entry.startedDateTime);
// Calculate the current request's end time by adding the time it needed to load to its start time
entryLoadTime.setMilliseconds(entryLoadTime.getMilliseconds() + entry.time);
// If the current request's end time is greater than the current latest request end time, then save it as new latest request end time
if (entryLoadTime > loadTime) {
loadTime = entryLoadTime;
}
});
var loadTimeSpan = loadTime - startTime;
执行此代码，变量loadTimeSpan 将包含所需的时间跨度（以毫秒为单位）。
重要提示：
这样计算的时间跨度可能仍然与 Firebug 或在线 HAR Viewer 显示的时间不同，因为它们根据两个请求之间经过的时间将请求分为不同的阶段。然后他们计算每个阶段的第一个请求到最后一个请求的时间跨度，并在最后总结这些时间跨度。
【讨论】：
forEach()调用的回调函数中的entry参数，那么是的。在这种情况下，请参阅documentation for forEach()。