每次调用Writer方法放回的PrintWriter对象的引用变量指向的是同一个PrintWriter方法。
既：
PrintWriter out1,out2;
out1=reponse.getWriter():
out2=reponse.getWriter():

out1.print("content outputed by out1<br>");
out2.println("content outputed by out2<br>");

浏览器端显示结果：
content outputed by out1
content outputed by out2


注意：

当在浏览器端查看源文件时，print()和println()方法在浏览器端显示的

public class IncludingServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {

   response.setContentType("text/html;charset=gb2312");
   //response.setCharacterEncoding("gb2312");
   PrintWriter out = response.getWriter();
   String china="中国";
   RequestDispatcher rd