<%@ taglib uri="

<c:redirect url="home.htm"/>
<c:redirect url="b.jsp">
<c:param name="data" value="jsp_passdata中文傳值"></c:param>
</c:redirect>

他們兩個作用相似
<jsp:forward page="/utils/errorReporter.jsp"/>

<jsp:forward page="/test4.jsp">
<jsp:param name="name" value="powerman"/>
<jsp:param name="address" value=" 北京西大街188號"/>
</jsp:forward>

<fmt:requestEncoding value="big5"/>

public abstract class HttpServletBean
extends HttpServlet

Simple extension of HttpServlet which treats its config parameters (init-param entries within the servlet tag in web.xml) as bean properties.

HttpServlet的簡單擴展用來處理 （init-param）in the web.xml
A handy superclass for any type of servlet. Type conversion of config parameters is automatic, with the corresponding setter method getting invoked with the converted value. It is also possible for subclasses to specify required properties. Parameters without matching bean property setter will simply be ignored.

This servlet leaves request handling to subclasses, inheriting the default behavior of HttpServlet (doGet, doPost, etc).

This generic servlet base class has no dependency on the Spring ApplicationContext concept. Simple servlets usually don't load their own context but rather access service beans from the Spring root application context, accessible via the filter's ServletContext (see WebApplicationContextUtils).

The FrameworkServlet class is a more specific servlet base class which loads its own application context. FrameworkServlet serves as direct base class of Spring's full-fledged DispatcherServlet.

public abstract class FrameworkServlet
extends HttpServletBean
implements ApplicationListener

Base servlet for Spring's web framework. Provides integration with a Spring application context, in a JavaBean-based overall solution.

spring web Framework的基礎(chǔ) servlet? ，提供在以javabean為基礎(chǔ)的整體解決方案已完成與spring應(yīng)用上下文的集成
This class offers the following functionality:
1.管理一個servlet一個網(wǎng)絡(luò)應(yīng)用上下文實例，這個servlet的配置由servlet命名空間里的bean來決定
2.根據(jù)請求處理發(fā)布事件，是否請求成功的被處理了

• Manages a WebApplicationContext instance per servlet. The servlet's configuration is determined by beans in the servlet's namespace.
• Publishes events on request processing, whether or not a request is successfully handled.

Subclasses must implement doService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) to handle requests. Because this extends HttpServletBean rather than HttpServlet directly, bean properties are automatically mapped onto it. Subclasses can override initFrameworkServlet() for custom initialization.

因為它繼承自httpservletBean 所以bean的屬性已經(jīng)被自動的裝配了，子類可以通過覆蓋initFrameworkServlet來定制初始化bean

Detects a "contextClass" parameter at the servlet init-param level, falling back to the default context class, XmlWebApplicationContext, if not found. Note that, with the default FrameworkServlet, a custom context class needs to implement the ConfigurableWebApplicationContext SPI.

Passes a "contextConfigLocation" servlet init-param to the context instance, parsing it into potentially multiple file paths which can be separated by any number of commas and spaces, like "test-servlet.xml, myServlet.xml". If not explicitly specified, the context implementation is supposed to build a default location from the namespace of the servlet.

Note: In case of multiple config locations, later bean definitions will override ones defined in earlier loaded files, at least when using Spring's default ApplicationContext implementation. This can be leveraged to deliberately override certain bean definitions via an extra XML file.

The default namespace is "'servlet-name'-servlet", e.g. "test-servlet" for a servlet-name "test" (leading to a "/WEB-INF/test-servlet.xml" default location with XmlWebApplicationContext). The namespace can also be set explicitly via the "namespace" servlet init-param.

				
<bean id="exampleInitBean" class="examples.ExampleBean" init-method="cleanup"/>
				
<bean id="exampleInitBean" class="examples.ExampleBean" destroy-method="cleanup"/>

public interface Lifecycle

Interface defining methods for start/stop lifecycle control. The typical use case for this is to control asynchronous processing.

Can be implemented by both components (typically a Spring bean defined in a Spring BeanFactory) and containers (typically a Spring ApplicationContext). Containers will propagate start/stop signals to all components that apply.

Can be used for direct invocations or for management operations via JMX. In the latter case, the MBeanExporter will typically be defined with an InterfaceBasedMBeanInfoAssembler, restricting the visibility of activity-controlled components to the Lifecycle interface.

Since:

2.0

Author:

Juergen Hoeller

See Also:

ConfigurableApplicationContext , AbstractMessageListenerContainer, SchedulerFactoryBean

Spring中Bean的生命周期

? ? 在傳統(tǒng)的Java應(yīng)用中，Bean的生命周期非常簡單。Java的關(guān)鍵詞new用來實例化Bean（或許他是非序列化的）。這樣就夠用了。相反，Bean的生命周期在Spring容器中更加細致。理解Spring Bean的生命周期非常重要，因為你或許要利用Spring提供的機會來訂制Bean的創(chuàng)建過程。 1. 容器尋找Bean的定義信息并且將其實例化。 2.受用依賴注入，Spring按照Bean定義信息配置Bean的所有屬性。 3.如果Bean實現(xiàn)了BeanNameAware接口，工廠調(diào)用Bean的setBeanName()方法傳遞Bean的ID。 4.如果Bean實現(xiàn)了BeanFactoryAware接口，工廠調(diào)用setBeanFactory()方法傳入工廠自身。 5.如果BeanPostProcessor和Bean關(guān)聯(lián)，那么它們的postProcessBeforeInitialzation()方法將被調(diào)用。 6.如果Bean指定了init-method方法，它將被調(diào)用。 7.最后，如果有BeanPsotProcessor和Bean關(guān)聯(lián)，那么它們的postProcessAfterInitialization()方法將被調(diào)用。 ??? 到這個時候，Bean已經(jīng)可以被應(yīng)用系統(tǒng)使用了，并且將被保留在Bean Factory中知道它不再需要。有兩種方法可以把它從Bean Factory中刪除掉。 1.如果Bean實現(xiàn)了DisposableBean接口，destory()方法被調(diào)用。 2.如果指定了訂制的銷毀方法，就調(diào)用這個方法。 ??? Bean在Spring應(yīng)用上下文的生命周期與在Bean工廠中的生命周期只有一點不同，唯一不同的是，如果Bean實現(xiàn)了ApplicationContextAwre接口，setApplicationContext()方法被調(diào)用。

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=[%5p] %d{HH:mm:ss} %c{1} - %m%n

log4j.rootLogger=WARN, stdout

log4j.category.com.springinaction=DEBUG
log4j.category.org.springframework=WARN

package com.springinaction.chapter01.knight;

import java.lang.reflect.Method;

import org.apache.log4j.Logger;
import org.springframework.aop.MethodBeforeAdvice;

public class MinstrelAdvice implements MethodBeforeAdvice {
? public void before(Method method, Object[] args, Object target)
????? throws Throwable {

??? Knight knight = (Knight) target;
???
??? Logger song = Logger.getLogger(target.getClass());
???
??? song.debug("Brave " + knight.getName() + " did " + method.getName());
? }
}

package com.springinaction.chapter01.knight;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.core.io.FileSystemResource;
public class KnightApp {
? private static final org.apache.log4j.Logger LOGGER = org.apache.log4j.Logger
????? .getLogger(KnightApp.class);
?
? public static void main(String[] args) throws Exception {
??? LOGGER.debug("Running KnightApp");
??? ApplicationContext m;
??? BeanFactory factory =
??????? new XmlBeanFactory(new FileSystemResource("knight.xml"));

///有XmlBeanFactory來負責具體的實現(xiàn)???? knight.xml必須要保存在項目的總目錄下面
Knight knight =
??????? (Knight) factory.getBean("knight");

??? knight.embarkOnQuest();
??? System.out.println("ok");
??? LOGGER.debug("KnightApp Finished");
? }
}

?Spring中ApplicationContext加載機制

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
??? "

///////在spring里所有的bean都是具體的實現(xiàn)，所謂的裝配bean就是裝配一個具體的實現(xiàn)
<beans>
? <bean id="quest"
????? class="com.springinaction.chapter01.knight.HolyGrailQuest"/>
/////轉(zhuǎn)配一個實現(xiàn)類，用來實現(xiàn)一個接口

JTS Java Transaction Service 是 J2EE 架構(gòu)的關(guān)鍵元素。它與 JTA?Java Transaction API 結(jié)合在一起，使我們能夠構(gòu)建對于各種系統(tǒng)和網(wǎng)絡(luò)故障都非常健壯的分布式應(yīng)用程序。事務(wù)是可靠應(yīng)用程序的基本構(gòu)建塊 —— 如果沒有事務(wù)的支持，編寫可靠的分布式應(yīng)用程序?qū)⑹欠浅＠щy的。幸運的是，JTS 執(zhí)行的大部分工作對于程序員都是透明的；J2EE 容器使事務(wù)劃分和資源征用對程序員來說幾乎是不可見的。這個由三個部分組成的系列文章的第一期講述了一些基礎(chǔ)知識，包括什么是事務(wù)，以及事務(wù)對于構(gòu)建可靠的分布式應(yīng)用程序來說至關(guān)重要的原因。

如果您閱讀過任何有關(guān) J2EE 的介紹性文章或者書籍，那么就會發(fā)現(xiàn)，只有一小部分資料是專門針對 Java Transaction Service（JTS）或 Java Transaction API（JTA）的。這并不是因為 JTS 是 J2EE 中不重要的部分或者可選部分 —— 恰恰相反。JTS 受到的關(guān)注之所以會比 EJB 技術(shù)少，是因為它為應(yīng)用程序提供的服務(wù)非常透明 —— 很多開發(fā)人員甚至沒有注意到在他們的應(yīng)用程序中事務(wù)在哪里開始和結(jié)束。在某種意義上，JTS 的默默無聞恰恰是它的成功：因為它非常有效地隱藏了事務(wù)管理的很多細節(jié)，因此，我們沒有聽說過或者談?wù)撨^很多關(guān)于它的內(nèi)容。但是，您可能想了解它在幕后都為您執(zhí)行什么功能。

毫不夸張地說，沒有事務(wù)就不能編寫可靠的分布式應(yīng)用程序。事務(wù)允許采用某種控制方式修改應(yīng)用程序的持久性狀態(tài)，以便使應(yīng)用程序?qū)τ诟鞣N各樣的系統(tǒng)故障（包括系統(tǒng)崩潰、網(wǎng)絡(luò)故障、電源故障甚至自然災(zāi)害）更加健壯。事務(wù)是構(gòu)建容錯、高可靠性以及高可用性應(yīng)用程序所需的基本構(gòu)建塊之一。

java:comp/env是組件的JNDI上下文的名字（實際上這個上下文也作為一種資源來處理了，資源查找的過程可以是這樣：jndictxt = ctxt.lookup(“java:comp/env”)然后用這個jndictxt來查找資源，ref = jndictxt.lookup("jdbc/SavingsAccountDB")。）jdbc/SavingsAccountDB是資源引用的JNDI名（The jdbc/SavingsAccountDB string is the JNDI name for the resource reference，這句話可能意味著資源引用實際上也跟資源一樣處理成一種JNDI綁定對象了，但是實際上應(yīng)該不是這樣，因為在部署描述符中它是引用名元素。因為譯者也不是高手，所以這里的具體實現(xiàn)細節(jié)有待讀者自己研究了：）所以JDBC的DataSource對象的JNDI名就存儲在java:comp/env/jdbc的上下文子對象中。（組件運行環(huán)境的上下文層次需要進一步了解）

5. 在Type列中選擇javax.sql.DataSource。前面說過它是數(shù)據(jù)庫連接工廠