常见问题F&Q(新手推荐)
类别: JSP教程
如何混合使用Jsp和SSI #include?
在JSP中可以使用如下方式包含?HTML:
<!--#include file="data.inc"-->
但是如果data.inc中包含JSP CODE ,我?可以使用:
<%@include file="data.inc"%>
如何?行一??程安全的JSP?
只需增加如下指令<br>
<%@ page isThreadSafe="false" %>
JSP如何?理HTML FORM中的?料?
通??置的request物件即可,如下:
<%<br>
String item = request.getParameter("item");
int howMany = new Integer(request.getParameter("units")).intvalue();
%>
在JSP如何包含一???文件?
??包含如下:<%@ include file="copyright.html" %>
??包含如下:<jsp:include page="copyright.html" flush="true"/>
在JSP中如何使用注??
主要有四中方法:
1。<%-- ? --%>
2。//
3。/**?**/
4。<!--?-->
在JSP中如何?行??重定向?
使用如下方式即可:response.sendRedirect("http://ybwen.home.chinaren.com/index.html";);
也能物理地改?HTTP HEADER?性,如下:
<%
response.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY);
String newLocn="/newpath/index.html";
response.setHeader("Location",newLocn);
%>
如何防止在JSP或SERVLET中的?出不被BROWSER保存在CACHE中?
把如下?本加入到JSP文件的?始即可:
<%
response.setHeader("Cache-Control","no-store"); file://HTTP 1.1
response.setHeader("Pragma","no-cache"); file://HTTP 1.0
response.setDateHeader ("Expires", 0); file://prevents caching at the proxy server
%>
在JSP中如何?置COOKIE?
COOKIE是作?HTTP HEADER的一部分被?送的,如下方法即可?置:
<%
Cookie mycookie = new Cookie("aName","avalue");
response.addCookie(mycookie);
%>
在JSP中如何?除一?COOKIE?
<%
Cookie killMyCookie = new Cookie("mycookie", null);
killMyCookie.setMaxAge(0);
killMyCookie.setPath("/");
response.addCookie(killMyCookie);
%>
在一?JSP的?求?理中如何停止JSP的?行?
如下例:
<%
if (request.getParameter("wen") != null) {
// do something
} else {
return;
}
%>
在JSP中如何定?方法?
你可以定?方法,但是你不能直接??JSP的?置物件,而是通???的方法??。如下:
<%!
public String howBadFrom(HttpServletRequest req) {
HttpSession ses = req.getSession();
...
return req.getRemoteHost();
}
%>
<%
out.print("in general,lao lee is not baddie ");
%>
<%= howBadFrom(request) %>
如果BROWSER已??了COOKIES,在JSP中我如何打?SESSION?跟??
使用URL重?即可,如下:
hello1.jsp
<%@ page session="true" %>
<%
Integer num = new Integer(100);
session.putvalue("num",num);
String url =response.encodeURL("hello2.jsp");
%>
hello2.jsp</a>
hello2.jsp
<%@ page session="true" %>
<%
Integer i= (Integer )session.getvalue("num");
out.println("Num value in session is "+i.intvalue());
%>
在JSP中能?送EMAIL??
可以使用SUN的?用包:sun.net.smtp包。如下?本使用SmtpClient??送EMAIL。
<%@ page import="sun.net.smtp.SmtpClient, java.io.*" %>
<%
String from="ybwen@sina.com";
String to="hewenjun@yeah.net, lei@who.com.cn";
try{
SmtpClient client = new SmtpClient("mail.xxxxx.xxx");
client.from(from);
client.to(to);
PrintStream message = client.startMessage();
message.println("To: " + to);
message.println("Subject: Sending email from JSP!");
message.println("This was sent from a JSP page!");
message.println();
message.println("Cool! :-)");
message.println();
message.println("Good Boy");
message.println("I\'m in genius.com");
message.println();
client.closeServer();
}
catch (IOException e){
System.out.println("ERROR SENDING EMAIL:"+e);
}
%>
在SERVLET中我能?用一?JSP?????
?然???,如下展示了如何在一?SERVLET控制???元??用一?JSP???面。
protected void sendErrorRedirect(HttpServletRequest request,
HttpServletResponse response, String errorPageURL,
Throwable e)
throws ServletException, IOException {
request.setAttribute ("javax.servlet.jsp.jspException", e);
getServletConfig().getServletContext().
getRequestDispatcher(errorPageURL).forward(request,
response);
}
public void doPost(HttpServletRequest request,HttpServletResponse response) {
try {
// do something
} catch (Exception ex) {
try {
sendErrorRedirect(request,response,"/jsp/MyErrorPage.jsp",ex);
} catch (Exception e) {
e.printStackTrace();
}
}
}
JSP如何?EJB SessionBean通??
下面的代?段作了很好的示?
<%@ page import="javax.naming.*, javax.rmi.PortableRemoteObject,
foo.AccountHome, foo.Account" %>
<%!
file://定?一??SessionBeanHome介面?例的全局引用
AccountHome accHome=null;
public void jspInit() {
file://?得Home介面?例
InitialContext cntxt = new InitialContext( );
Object ref= cntxt.lookup("java:comp/env/ejb/AccountEJB");
accHome = (AccountHome)PortableRemoteObject.narrow(ref,AccountHome.class);
}
%>
<%
file://?例化SessionBean
Account acct = accHome.create();
file://?用?端方法
acct.doWhatever(...);
// 如此等等
%>
在JSP中可以使用如下方式包含?HTML:
<!--#include file="data.inc"-->
但是如果data.inc中包含JSP CODE ,我?可以使用:
<%@include file="data.inc"%>
如何?行一??程安全的JSP?
只需增加如下指令<br>
<%@ page isThreadSafe="false" %>
JSP如何?理HTML FORM中的?料?
通??置的request物件即可,如下:
<%<br>
String item = request.getParameter("item");
int howMany = new Integer(request.getParameter("units")).intvalue();
%>
在JSP如何包含一???文件?
??包含如下:<%@ include file="copyright.html" %>
??包含如下:<jsp:include page="copyright.html" flush="true"/>
在JSP中如何使用注??
主要有四中方法:
1。<%-- ? --%>
2。//
3。/**?**/
4。<!--?-->
在JSP中如何?行??重定向?
使用如下方式即可:response.sendRedirect("http://ybwen.home.chinaren.com/index.html";);
也能物理地改?HTTP HEADER?性,如下:
<%
response.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY);
String newLocn="/newpath/index.html";
response.setHeader("Location",newLocn);
%>
如何防止在JSP或SERVLET中的?出不被BROWSER保存在CACHE中?
把如下?本加入到JSP文件的?始即可:
<%
response.setHeader("Cache-Control","no-store"); file://HTTP 1.1
response.setHeader("Pragma","no-cache"); file://HTTP 1.0
response.setDateHeader ("Expires", 0); file://prevents caching at the proxy server
%>
在JSP中如何?置COOKIE?
COOKIE是作?HTTP HEADER的一部分被?送的,如下方法即可?置:
<%
Cookie mycookie = new Cookie("aName","avalue");
response.addCookie(mycookie);
%>
在JSP中如何?除一?COOKIE?
<%
Cookie killMyCookie = new Cookie("mycookie", null);
killMyCookie.setMaxAge(0);
killMyCookie.setPath("/");
response.addCookie(killMyCookie);
%>
在一?JSP的?求?理中如何停止JSP的?行?
如下例:
<%
if (request.getParameter("wen") != null) {
// do something
} else {
return;
}
%>
在JSP中如何定?方法?
你可以定?方法,但是你不能直接??JSP的?置物件,而是通???的方法??。如下:
<%!
public String howBadFrom(HttpServletRequest req) {
HttpSession ses = req.getSession();
...
return req.getRemoteHost();
}
%>
<%
out.print("in general,lao lee is not baddie ");
%>
<%= howBadFrom(request) %>
如果BROWSER已??了COOKIES,在JSP中我如何打?SESSION?跟??
使用URL重?即可,如下:
hello1.jsp
<%@ page session="true" %>
<%
Integer num = new Integer(100);
session.putvalue("num",num);
String url =response.encodeURL("hello2.jsp");
%>
hello2.jsp</a>
hello2.jsp
<%@ page session="true" %>
<%
Integer i= (Integer )session.getvalue("num");
out.println("Num value in session is "+i.intvalue());
%>
在JSP中能?送EMAIL??
可以使用SUN的?用包:sun.net.smtp包。如下?本使用SmtpClient??送EMAIL。
<%@ page import="sun.net.smtp.SmtpClient, java.io.*" %>
<%
String from="ybwen@sina.com";
String to="hewenjun@yeah.net, lei@who.com.cn";
try{
SmtpClient client = new SmtpClient("mail.xxxxx.xxx");
client.from(from);
client.to(to);
PrintStream message = client.startMessage();
message.println("To: " + to);
message.println("Subject: Sending email from JSP!");
message.println("This was sent from a JSP page!");
message.println();
message.println("Cool! :-)");
message.println();
message.println("Good Boy");
message.println("I\'m in genius.com");
message.println();
client.closeServer();
}
catch (IOException e){
System.out.println("ERROR SENDING EMAIL:"+e);
}
%>
在SERVLET中我能?用一?JSP?????
?然???,如下展示了如何在一?SERVLET控制???元??用一?JSP???面。
protected void sendErrorRedirect(HttpServletRequest request,
HttpServletResponse response, String errorPageURL,
Throwable e)
throws ServletException, IOException {
request.setAttribute ("javax.servlet.jsp.jspException", e);
getServletConfig().getServletContext().
getRequestDispatcher(errorPageURL).forward(request,
response);
}
public void doPost(HttpServletRequest request,HttpServletResponse response) {
try {
// do something
} catch (Exception ex) {
try {
sendErrorRedirect(request,response,"/jsp/MyErrorPage.jsp",ex);
} catch (Exception e) {
e.printStackTrace();
}
}
}
JSP如何?EJB SessionBean通??
下面的代?段作了很好的示?
<%@ page import="javax.naming.*, javax.rmi.PortableRemoteObject,
foo.AccountHome, foo.Account" %>
<%!
file://定?一??SessionBeanHome介面?例的全局引用
AccountHome accHome=null;
public void jspInit() {
file://?得Home介面?例
InitialContext cntxt = new InitialContext( );
Object ref= cntxt.lookup("java:comp/env/ejb/AccountEJB");
accHome = (AccountHome)PortableRemoteObject.narrow(ref,AccountHome.class);
}
%>
<%
file://?例化SessionBean
Account acct = accHome.create();
file://?用?端方法
acct.doWhatever(...);
// 如此等等
%>
- 上一篇: 汉字问题深入谈
- 下一篇: JAVA常见中文问题的解决方案
-= 资 源 教 程 =-
文 章 搜 索