ani*_*tin 13 jsf servlets httpresponse
我意识到这是一个鸡和蛋的问题,并且不可能准确地解决呈现页面所花费的时间(或响应的大小)并将该数字插入页面本身而不影响任何一个度量.不过,我正在寻找一种方法来将一个数字部分插入JSF/Facelets/Seam应用程序的页面中.
例如,在某个地方的.jsf页面的底部:
<!-- page size: 10.3Kb -->
<!-- render time: 0.2s -->
我遇到过JSFUnit的JSFTimer,非常方便.但是,相位侦听器方法不允许将RENDER_RESPONSE阶段的结果插入到页面中.不知道如何访问目前为止编码的响应的大小.
在RENDER_RESPONSE结束时或之后是否有一种快速而肮脏的方式来连接某种后处理事件,并将这两个数字注入到即将呈现的页面中？接近这个的一种方法可能是通过servlet过滤器,但我正在寻找更简单的东西; 也许是Seam或Facelets的一招
谢谢,
-A
Bal*_*usC 22
这是Apache Commons IO 的完美用例CountingOutputStream.您需要创建一个Filter它使用HttpServletResponseWrapper来代替OutputStream这一个响应并替换Writer以及应裹裹OutputStream.然后得到的保持HttpServletResponseWrapper实例在请求范围,使你可以得到getByteCount()从CountingOutputStream.
这是一个启动示例CountingFilter:
public class CountingFilter implements Filter {
@Override
public void init(FilterConfig arg0) throws ServletException {
// NOOP.
}
@Override
public void doFilter(ServletRequest request, final ServletResponse response, FilterChain chain) throws IOException, ServletException {
HttpServletResponse httpres = (HttpServletResponse) response;
CountingServletResponse counter = new CountingServletResponse(httpres);
HttpServletRequest httpreq = (HttpServletRequest) request;
httpreq.setAttribute("counter", counter);
chain.doFilter(request, counter);
counter.flushBuffer(); // Push the last bits containing HTML comment.
}
@Override
public void destroy() {
// NOOP.
}
}
的CountingServletResponse:
public class CountingServletResponse extends HttpServletResponseWrapper {
private final long startTime;
private final CountingServletOutputStream output;
private final PrintWriter writer;
public CountingServletResponse(HttpServletResponse response) throws IOException {
super(response);
startTime = System.nanoTime();
output = new CountingServletOutputStream(response.getOutputStream());
writer = new PrintWriter(output, true);
}
@Override
public ServletOutputStream getOutputStream() throws IOException {
return output;
}
@Override
public PrintWriter getWriter() throws IOException {
return writer;
}
@Override
public void flushBuffer() throws IOException {
writer.flush();
}
public long getElapsedTime() {
return System.nanoTime() - startTime;
}
public long getByteCount() throws IOException {
flushBuffer(); // Ensure that all bytes are written at this point.
return output.getByteCount();
}
}
的CountingServletOutputStream:
public class CountingServletOutputStream extends ServletOutputStream {
private final CountingOutputStream output;
public CountingServletOutputStream(ServletOutputStream output) {
this.output = new CountingOutputStream(output);
}
@Override
public void write(int b) throws IOException {
output.write(b);
}
@Override
public void flush() throws IOException {
output.flush();
}
public long getByteCount() {
return output.getByteCount();
}
}
您可以在任何(甚至非JSF)页面中使用它,如下所示:
<!DOCTYPE html>
<html
xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html">
<h:head>
<title>Counting demo</title>
</h:head>
<h:body>
<h1>Hello World</h1>
</h:body>
</html>
<!-- page size: #{counter.byteCount / 1000}KB -->
<!-- render time: #{counter.elapsedTime / 1000000}ms -->
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