Servlet中Response的flushBuffer()是怎么用的?
Response的flushBuffer()的用法
馬克- to-win:馬克 java社區(qū):防盜版實名手機尾號: 73203。
馬克-to-win:response有個buffer,flushBuffer()會強行把Buffer的內(nèi)容寫到客戶端瀏覽器。(Forces any content in the buffer to be written to the client. ),如果你不flushBuffer的話,當程序運行到最后的右大括號的時候,Tomcat也會把Response的Buffer的東西,一次性發(fā)給客戶端。這就是在我們前面的hello world Servlet的例子當中,沒有加flushBuffer的原因。
例:3.2.1
package com;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ServletHello1 extends HttpServlet {
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
String myN = request.getParameter("myName");
PrintWriter pw = response.getWriter();
for (int i = 0; i < 5; i++) {
pw.println("back is " + myN);
/*下面兩種flush方法的效果完全一樣。后面的close方法針對他們倆都起效。
*/
// pw.flush();
response.flushBuffer();
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
/*上面的兩種flush,只要加上下面一句close,之后的東西都打印不出來了。但也不報錯。*/
// pw.close();
pw.println("Mark-to-win Finished");
}
}
瀏覽器里面的輸出結果是:(一共打印了五遍。遍與遍的間隔是兩秒。)
back is Mark-to-win back is Mark-to-win back is Mark-to-win back is Mark-to-win back is Mark-to-win Mark-to-win Finished