BlogJava-我的java历程-随笔分类-Jsp&Servlethttp://www.blogjava.net/phe441/category/18252.htmlzh-cnFri, 06 Jul 2007 18:55:43 GMTFri, 06 Jul 2007 18:55:43 GMT60tomcat5.5.17+jstl1.2+servlet2.5+jsp2.1配置http://www.blogjava.net/phe441/archive/2007/07/06/128560.htmllandrillandrilFri, 06 Jul 2007 05:35:00 GMThttp://www.blogjava.net/phe441/archive/2007/07/06/128560.htmlhttp://www.blogjava.net/phe441/comments/128560.htmlhttp://www.blogjava.net/phe441/archive/2007/07/06/128560.html#Feedback0http://www.blogjava.net/phe441/comments/commentRss/128560.htmlhttp://www.blogjava.net/phe441/services/trackbacks/128560.htmltomcat5.5.17+jstl1.2+servlet2.5+jsp2.1配置

在此我使用的环境是：
tomcat5.5.17
jstl1.2
servlet2.5
jsp2.1

我以一个简单的例子hello1来说明吧，发布工程时最重要的就是目录结构了，hello1是根目录，放在tomcat中的webapps里，先看看目录结构：
hello1\index.jsp
hello1\response.jsp
hello1\WEB-INF\lib\javaee.jar
hello1\WEB-INF\lib\jsf-api.jar
hello1\WEB-INF\lib\jsf-impl.jar
hello1\WEB-INF\lib\jstl-1.2.jar
hello1\WEB-INF\web.xml

如果你按照以上目录发布工程，抛出以下异常：
(1)  java.lang.NoClassDefFoundError: javax/el/ExpressionFactory
(2)  或打开页面后显示：

HTTP Status 404 - /hello1/

type Status report

message /hello1/

description The requested resource (/hello1/) is not available.

Apache Tomcat/5.5.17


则将javaee.jar包再copy一份放在tomcat目录的common\lib下就不会了。
关于用到的javaee.jar、jsf-api.jar、jsf-impl.jar、jstl-1.2.jar这四个包可以通过myeclipse中获得，如果你安装了myeclipse5.5的话，我安装的是MyEclipse 5.5.1 GA，这四个包的所在的目录是：MyEclipse 5.5.1 GA\eclipse\plugins\com.genuitec.eclipse.j2eedt.core_5.5.1\data\libraryset\EE_5\

到此，再给出具体的文件代码吧。
(1)  hello1\index.jsp

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>

<html>
<head><title>Hello</title></head>
<body bgcolor="white">
<h2>Hello, my name is Duke. What's yours?</h2>
<form method="get">
<input type="text" name="username" size="25">
<p></p>
<input type="submit" value="Submit">
<input type="reset" value="Reset">
</form>

<c:if test="${fn:length(param.username) > 0}" >
  <%@include file="response.jsp" %>
</c:if>
</body>
</html>

(2)  hello1\response.jsp

<h2><font color="black">Hello, ${param.username}!</font></h2>

(3)  hello1\WEB-INF\web.xml

<?xml version="1.0" encoding="ISO-8859-1"?>

<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee web-app_2_5.xsd"
         version="2.5">

<jsp-config> 
 <jsp-property-group>
  <display-name>hello1</display-name>
  <url-pattern>*.jsp</url-pattern>
  <el-ignored>false</el-ignored>
  <scripting-invalid>false</scripting-invalid>
  <is-xml>false</is-xml>
  <!-- <include-prelude>/template/prelude.jspf</include-prelude> -->
  <!-- <include-coda>/template/coda.jspf</include-coda> -->
 </jsp-property-group>
</jsp-config>
</web-app>


成功之后页面显示为：

Hello, my name is Duke. What's yours?

 

Hello, afdfadsfads!



landril 2007-07-06 13:35 发表评论
]]>会话跟踪技术--session的使用http://www.blogjava.net/phe441/archive/2007/04/28/114429.htmllandrillandrilSat, 28 Apr 2007 13:33:00 GMThttp://www.blogjava.net/phe441/archive/2007/04/28/114429.htmlhttp://www.blogjava.net/phe441/comments/114429.htmlhttp://www.blogjava.net/phe441/archive/2007/04/28/114429.html#Feedback0http://www.blogjava.net/phe441/comments/commentRss/114429.htmlhttp://www.blogjava.net/phe441/services/trackbacks/114429.html会话跟踪技术--session的使用

 

会话跟踪：

1、 使用隐藏表单字段

<INPUT TYPE=”HIDDEN” NAME=”session” VALUE=”landril”

2、 URL重写

http://host/path/file.jsp?sessionid=landril

3、 持久Cookie

4、 会话HttpSession

 

一、使用session的简单步骤

获取HttpSession（request.getSession()方法）对象，查找与该会话相关的信息（session.getAttribute()），存储会话中的信息（session.setAttribute()），删除会话中的数据（session.removeAttribute()），删除当前会话（session.invalidate()）

在session中，可以存储任意数量的键值对，通过键即可获取相应的值，即使用：session.getAttribute(“key”);。

 

二、session的常用方法

1、 getAttribute()：从session中获取以前存储的值

2、 getAttributeNames()：返回session中所有属性的名称

3、 setAttribute()：将键与值关联起来，存储进session

4、 removeAttribute()：删除session中存储的对应键的值

5、 invalidate()：删除整个session及其存储的键值

6、 logout()：注销当前用户

7、 getId()：获取每个session对应的唯一ID

8、 getCreationTime()：获取session创建的时间

9、 getLastAccessedTime()：获取session最后被访问的时间

10、              getMaxInactiveInterval()：在用户没有访问的情况下，会话在被自动废弃之前应该保持多长时间

 

三、使用session的一个例子，拥有购物车的在线商店

 

1、CatalogPage.java

 

package com.landril.session;

 

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 CatalogPage extends HttpServlet {

 

    private CatalogItem[] items;

 

    private String[] itemIds;

 

    private String title;

 

    protected void setItems(String[] itemIds) {

       this.itemIds = itemIds;

       items = new CatalogItem[itemIds.length];

       for (int i = 0; i < items.length; i++) {

           items[i] = Catalog.getItem(itemIds[i]);

       }

    }

 

    protected void setTitle(String title) {

       this.title = title;

    }

 

    public void doGet(HttpServletRequest request, HttpServletResponse response)

           throws ServletException, IOException {

      

       if(items == null){

           response.sendError(response.SC_NOT_FOUND,"Missing Items:");

           return;

       }

      

       response.setContentType("text/html");

       PrintWriter out = response.getWriter();

       out.println("<html><head><title>"+title+"</title></head><body><h3>"+title+"</h3>");

       CatalogItem item;

       for (int i = 0; i < items.length; i++) {

           out.println("<hr>");

           item = items[i];

           if(item == null)

              out.println("Unknow itemId: "+itemIds[i]);

           else{

              out.println();

              String formURL = request.getContextPath()+"/orderPage";

              formURL = response.encodeURL(formURL);

             

              out.println("<form action='"+formURL+"'>");

              out.println("<input type='hidden' name='itemId' value='"+item.getItemId()+"'>");

              out.println(new String(item.getSDesc().getBytes("utf-8"),"GBK")+"$"+item.getPrice()+item.getLDesc());

              out.println("<input type='submit' value='add to shopping cart'></form></body></html>");

           }

       }

    }

}

 

2、ComputerBook.java

 

package com.landril.session;

 

public class ComputerBook extends CatalogPage{

    public void init(){

       String[] ids = {"book1","book2","book3","book4"};

       setItems(ids);

       setTitle("Japanese Book");

    }

}

 

3、JapaneseBook.java

 

package com.landril.session;

 

public class JapaneseBook extends CatalogPage{

    public void init(){

       String[] ids = {"book5","book6"};

       setItems(ids);

       setTitle("Computer Book");

    }

}

 

4、OrderPage.java

 

package com.landril.session;

 

import java.io.IOException;

import java.io.PrintWriter;

import java.util.List;

 

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

 

public class OrderPage extends HttpServlet {

 

    public void doGet(HttpServletRequest request, HttpServletResponse response)

           throws ServletException, IOException {

       HttpSession session = request.getSession();

       ShoppingCart cart;

       synchronized(session){

           cart = (ShoppingCart)session.getAttribute("shop");

           if(cart == null){

              cart = new ShoppingCart();

              session.setAttribute("shop", cart);

           }

           String itemId = request.getParameter("itemId");

           if(itemId != null){

              String num = request.getParameter("num");

              if(num == null)

                  cart.addItem(itemId);

              else{

                  int numItems;

              try {

                  numItems = Integer.parseInt(num);

              } catch (NumberFormatException e) {

                  numItems = 1;

              }

              cart.setNum(itemId, numItems);

              }

           }

       }

      

       response.setContentType("text/html");

       PrintWriter out = response.getWriter();

       String title = "Your Order";

       out.println("<html><head><title>"+title+"</title></head><body><h3>"+title+"</h3>");

       synchronized(session){

           List<ItemOrder> itemOrders = cart.getItemOrders();

           if(itemOrders.size() == 0)

              out.println("No items");

           else{

              out.println("<table border=1><tr><th>Item ID<th>Short Description<th>Long Description<th>Unit Price<th>Number<th>Total Price");

              ItemOrder order;

              for (int i = 0; i < itemOrders.size(); i++) {

                  order = (ItemOrder)itemOrders.get(i);

                  out.println("<tr><td>"+order.getItemId()+"<td>"+order.getSDesc()+"<td>"+order.getLDesc()+"<td>"+order.getUnitPrice()+"<td>");

                  out.println("<form><input type='hidden' name='itemId' value='"+order.getItemId()+"'>");

                  out.println("<input type='text' name='num' size=3 value='"+order.getNum()+"'>");

                  out.println("<input type='submit' value='update order'></form><td>");

                  out.println(order.getTotalPrice());

               }

             

              String checkURL = response.encodeURL(request.getContextPath()+"/check.html");

              out.println("</table><form action='"+checkURL+"'>");

              out.println("<input type='submit' value='submit'></form></body></html>");

           }

       }

    }

}

 

5、ShoppingCart.java

 

package com.landril.session;

 

import java.util.ArrayList;

import java.util.List;

 

public class ShoppingCart {

    private List<ItemOrder> itemOrders;

 

    public ShoppingCart() {

       itemOrders = new ArrayList<ItemOrder>();

    }

   

    public List<ItemOrder> getItemOrders(){

       return itemOrders;

    }

   

    public synchronized void addItem(String itemId){

       ItemOrder order;

       for(int i=0;i<itemOrders.size();i++){

           order = (ItemOrder)itemOrders.get(i);

           if(itemId.equals(order.getItemId())){

              order.addNum();

              return;

           }

       }

       ItemOrder newOrd = new ItemOrder(Catalog.getItem(itemId));

       itemOrders.add(newOrd);

    }

   

    public synchronized void setNum(String itemId,int num){

       ItemOrder order;

       for (int i = 0; i < itemOrders.size(); i++) {

           order = (ItemOrder)itemOrders.get(i);

           if(itemId.equals(order.getItemId())){

              if(num <=0)

                  itemOrders.remove(i);

              else

                  order.setNum(num);

           }

           return;

       }

       ItemOrder newOrd = new ItemOrder(Catalog.getItem(itemId));

       itemOrders.add(newOrd);

    }

}

 

6、CatalogItem.java

 

package com.landril.session;

 

public class CatalogItem {

    private String itemId;

 

    private String sDesc;

 

    private String lDesc;

 

    private float price;

 

    public String getItemId() {

       return itemId;

    }

 

    public void setItemId(String itemId) {

       this.itemId = itemId;

    }

 

    public String getLDesc() {

       return lDesc;

    }

 

    public void setLDesc(String desc) {

       lDesc = desc;

    }

 

    public float getPrice() {

       return price;

    }

 

    public void setPrice(float price) {

       this.price = price;

    }

 

    public String getSDesc() {

       return sDesc;

    }

 

    public void setSDesc(String desc) {

       sDesc = desc;

    }

 

    public CatalogItem(String itemId, String desc, String desc2, float price) {

       super();

       this.itemId = itemId;

       sDesc = desc;

       lDesc = desc2;

       this.price = price;

    }

}

 

7、ItemOrder.java

 

package com.landril.session;

 

public class ItemOrder {

    private CatalogItem item;

 

    private int num;

 

    public ItemOrder(CatalogItem item) {

       setItem(item);

       setNum(1);

    }

 

    public CatalogItem getItem() {

       return item;

    }

 

    public void setItem(CatalogItem item) {

       this.item = item;

    }

 

    public int getNum() {

       return num;

    }

 

    public void setNum(int num) {

       this.num = num;

    }

 

    public String getItemId() {

       return item.getItemId();

    }

 

    public String getSDesc() {

       return item.getSDesc();

    }

 

    public String getLDesc() {

       return item.getLDesc();

    }

 

    public float getUnitPrice() {

       return item.getPrice();

    }

 

    public void addNum() {

       setNum(num + 1);

    }

 

    public void cancelOrder() {

       setNum(0);

    }

 

    public float getTotalPrice() {

       return num * getUnitPrice();

    }

 

}

 

8、Catalog.java

 

package com.landril.session;

 

public class Catalog {

    private static CatalogItem[] items = {

           new CatalogItem("book1", "Hibernate", "Hibernate，Hibernate", 57),

           new CatalogItem("book2", "Spring", "Spring，Spring", 36),

           new CatalogItem("book3", "Tomcat", "Tomcat，Tomcat", 23),

           new CatalogItem("book4", "Jboss", "Jboss，Jboss", 35),

           new CatalogItem("book5", "Japanese1", "Japanese1，Japanese1", 35),

           new CatalogItem("book6", "Japanese2", "Japanese2，Japanese2", 23) };

 

    public static CatalogItem getItem(String itemId) {

       CatalogItem item;

       if (itemId == null)

           return null;

       for (int i = 0; i < items.length; i++) {

           item = items[i];

           if (itemId.equals(item.getItemId()))

              return item;

       }

       return null;

    }

}

 

9、check.html

 

<html>

<head>

<title>checking out</title>

</head>

<body>

Checking out

</body>



landril 2007-04-28 21:33 发表评论
]]>Servlet基础知识及常用类http://www.blogjava.net/phe441/archive/2007/04/28/114427.htmllandrillandrilSat, 28 Apr 2007 13:32:00 GMThttp://www.blogjava.net/phe441/archive/2007/04/28/114427.htmlhttp://www.blogjava.net/phe441/comments/114427.htmlhttp://www.blogjava.net/phe441/archive/2007/04/28/114427.html#Feedback0http://www.blogjava.net/phe441/comments/commentRss/114427.htmlhttp://www.blogjava.net/phe441/services/trackbacks/114427.htmlServlet基础知识及常用类

 

一、Servlet生命周期

服务器加载Servlet，创建Servlet类的实例，调用Servlet的init()方法，处理客户端的服务调用（如果收到请求，调用service()方法，service()方法处理请求并将结果返回客户端，等待下一下请求，重复），Servlet在服务器调用destroy()方法后被卸载

 

二、会话跟踪技术

1、 使用隐藏表单字段

<INPUT TYPE=”HIDDEN” NAME=”session” VALUE=”landril”

2、 URL重写

http://host/path/file.jsp?sessionid=landril

3、 持久Cookie

4、 会话HttpSession

 

ServletRequest：用于将请求的信息传送给Servlet

ServletResponse：提供服务器对客户端请求的响应

RequestDispatcher：接收用户端的请求并将其发送到任何资源，RequestDispatcher对象用作资源的封装器，通过路径或名称指定

ServletConfig：定义Servlet配置对象，可以从web.xml文件中获取初始化参数的值以及对ServletContext对象的引用

ServletContext：让Servlet查找有关Servlet引擎及其环境的信息



landril 2007-04-28 21:32 发表评论
]]>Cookie的使用http://www.blogjava.net/phe441/archive/2007/04/10/109601.htmllandrillandrilTue, 10 Apr 2007 04:37:00 GMThttp://www.blogjava.net/phe441/archive/2007/04/10/109601.htmlhttp://www.blogjava.net/phe441/comments/109601.htmlhttp://www.blogjava.net/phe441/archive/2007/04/10/109601.html#Feedback0http://www.blogjava.net/phe441/comments/commentRss/109601.htmlhttp://www.blogjava.net/phe441/services/trackbacks/109601.htmlCookie的使用

 

一、cookie的作用

在我们平常写的B/S程序中，会经常用到cookie，主要有以下一些作用：

1、 记录用户名和密码

以及该用户需要保存的一些信息，如购物购站，使用cookie，可以让用户自动登录到站点等。

2、 定制站点

可以使用cookie来记录用户的偏好。

3、 定向广告

可以使用cookie来记录用记经常访问的主题，并向他们显示与这些主题相关的广告。

 

二、向客户程序发送cookie

1、 创建cookie对象

Cookie c = new Cookie(“userId”,”landril”);

2、 设置最大时效，默认该cookie是存储在浏览器的内在中，用户关闭浏览器则被删除，下面的方法是将cookie存储在硬盘上。

c.setMaxAge(60*60*24);//一天，如果设置为0则是删除该cookie

3、 将cookie放入到HTTP响应报头，可以使用HttpServletResponse的addCookie方法，此方法不修改之前指定的Set-Cookie报头，而是创建新的报头。

response.addCookie(c);

       注意：设置cookie的步骤为创建cookie对象，设置最大时效，将cookie放入响应报头，即发送到客户程序，记住一定要将cookie发送到客户程序

 

三、从客户端读取cookie

1、 调用HttpServletRequest的getCookies得到一个Cookie对象的数组

2、 对数组进行循环，调用cookie的getName方法，获取具体的cookie的值

Cookie[] cookies = request.getCookies();

if(cookies != null){

for(int i=0;i<cookies.length;i++){

        Cookie c = cookies[i];

        if(“userId”.equals(c.getName())){

        System.out.println(c.getValue());

}

}

}

 

四、cookie的常用方法

1、 setComment()/getComment()：指定或查找与该cookie相关的注释

2、 setDomain()/getDomain()：设置或读取该cookie适用的域

3、 setMaxAge()/getMaxAge()：操作cookie保留的时间，多长时间后过期

4、 getName()：读取cookie的名称

5、 setPath()/getPath()：设置或取得cookie适用的路径

cookie.setPath(“/”);指定服务器的所有页面都应该收到该cookie

6、 setSource()/getSource()：指定cookie是否只能通过加密连接（SSL）

默认false，表示cookie适用所有连接

7、 setValue()/getValue()：指定或获取cookie的值

 

五、使用cookie

 

1、RepeatServlet.java

public class RepeatServlet extends HttpServlet {

 

    public void doGet(HttpServletRequest request, HttpServletResponse response)

           throws ServletException, IOException {

        boolean newa = true;

        Cookie[] cookies = request.getCookies();

        if(cookies != null){

           for (int i = 0; i < cookies.length; i++) {

               Cookie c = cookies[i];

               if ((c.getName().equals("repeat")) && (c.getValue().equals("true"))) {

                  newa = false;

                   break;

               }

           }

       }

      

        String title;

       if (newa) {

           Cookie rtn = new Cookie("repeat"," true");

           rtn.setMaxAge(60*60*24*365);

           response.addCookie(rtn);

           title = "First Welcome";

       } else {

           title = "Welcom Back";

       }

      

        response.setContentType("text/html");

        PrintWriter out = response.getWriter();

        out.println("<html><body><h3>");

        out.println(title);

        out.println("</h3></body></html>");

    }

 

    public void doPose(HttpServletRequest request, HttpServletResponse response)

           throws ServletException, IOException {

        doGet(request,response);

    }

}

 

2、CookieUtil.java

public class CookieUtil{

 

    public static String getValue(HttpServletRequest request,String cName,String value){

        Cookie[] cookies = request.getCookies();

        if(cookies != null){

           for (int i = 0; i < cookies.length; i++) {

               Cookie cookie = cookies[i];

               if (cName.equals(cookie.getName())) {

                   return cookie.getValue();

               }

           }

       }

        return value;

    }

   

    public static Cookie getCookie(HttpServletRequest request,String cName){

        Cookie[] cookies = request.getCookies();

        if(cookies != null){

           for (int i = 0; i < cookies.length; i++) {

               Cookie cookie = cookies[i];

               if (cName.equals(cookie.getName())) {

                   return cookie;

               }

           }

       }

        return null;

    }

}

 

3、AccessCountServle.java 记录访问数

public class AccessCountServlet extends HttpServlet {

 

    public void doGet(HttpServletRequest request, HttpServletResponse response)

           throws ServletException, IOException {

      

        String acount = CookieUtil.getValue(request, "acc", "1");

       int count = Integer.parseInt(acount);

        Cookie cookie = new Cookie("acc",String.valueOf(count+1));

        cookie.setMaxAge(60*60*24*365);

        response.addCookie(cookie);

      

        response.setContentType("text/html");

        PrintWriter out = response.getWriter();

        out.println("<html><body>Hello,the number is<h3>");

        out.println(count);

        out.println("</h3></body></html>");

    }

   

    public void doPost(HttpServletRequest request, HttpServletResponse response)

    throws ServletException, IOException {

        doGet(request,response);

    }

}



landril 2007-04-10 12:37 发表评论
]]>