10. 设置web模块springapp的属性Content,加入文件log4j.properties,因为classes目录是自动产生的,这一步是为了把文件log4j.properties加到classes目录。
11. 设置Run Configuration,选菜单Run-Configurations,新建一个Run Configuration,Type选Server,Launch URI设置为:/springapp/hello.htm,给它取名为hello
12. 运行,你会在messages窗口中看到如下信息:
資訊: Server startup in 9253 ms
2004-11-05 15:05:00,585 INFO [spring.SpringappController] - <SpringappController - returning hello view>
2004/11/5 下午 03:05:00 org.springframework.web.servlet.view.AbstractCachingViewResolver resolveViewName
資訊: Cached view 'hello.jsp'
在myProject/Tomcat/springapp.log文件中增加了一行如下所示:
2004-11-05 15:11:32,348 INFO [spring.SpringappController] - <SpringappController - returning hello view>
这说明你已成功建立了基本的spring应用。
jstl的支持,设置工程文件的属性,选菜单Project-Project Properties,将jstl库加入Path/Required Libraries。
14. 改进前面的例子,改进的文件如下:
增加“header”文件include.jsp,这是一些jsp文件的公用部分,这样可以使得开发和维护更容易。所有jsp文件放在web-inf/jsp目录下,为的是只有Controller可以访问View。
springapp/war/WEB-INF/jsp/include.jsp
| <%@ page session="false"%> <%@ taglib prefix="c" uri="http://java.sun.com/jstl/core" %> <%@ taglib prefix="fmt" uri="http://java.sun.com/jstl/fmt" %> |
利用JSTL,<c:redirect>将页面重定向到Controller,这样就建立了index.jsp和应用架构的联系。
springapp/war/index.jsp
| <%@ include file="/WEB-INF/jsp/include.jsp" %> <%-- Redirected because we can't set the welcome page to a virtual URL. --%> <c:redirect url="/hello.htm"/> |
利用JSTL的<c:out>标记,把从Model提取的,传递给View的当前日期和时间作为输出。
springapp/war/WEB-INF/jsp/hello.jsp
| <%@ include file="/WEB-INF/jsp/include.jsp" %> <html> <head><title>Hello :: Spring Application</title></head> <body> <h1>Hello - Spring Application</h1> <p>Greetings, it is now <c:out value="${now}"/> </p> </body> </html> |
在SpringappController.java中增加包含了当前日期和时间的string作为Model
springapp/src/SpringappController.java
| import org.springframework.web.servlet.mvc.Controller; import org.springframework.web.servlet.ModelAndView; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class SpringappController implements Controller { /** Logger for this class and subclasses */ protected final Log logger = LogFactory.getLog(getClass()); public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String now = (new java.util.Date()).toString(); logger.info("returning hello view with " + now); return new ModelAndView("WEB-INF/jsp/hello.jsp", "now", now); } } |
15. 浏览改进后的结果http://localhost:8080/springapp,首先访问index.jsp,然后重定向到hello.htm,接著把控制交给Controller,Controller把日期和时间传送给View。
只能在浏览器这样测试。在JBuilder2005中设置Run Configuration不能访问http://localhost:8080/springapp,但可以访问http://localhost:8080/springapp/index.jsp
在上面的例子中,Controller指定了View的完全路径,使得Controller和View之间存在不必要的依赖。为了移出这种依赖,我们可以用类ResourceBundleViewResolver 和 a SimpleUrlHandlerMapping在属性文件中定义这种依赖,对于简单的情形,我们也可以利用InternalResourceViewResolver设置前缀和后缀,下面就用第二种方法。修改文件springapp-servlet.xml包含ViewResolver设置,我们还选择使用JstlView,这使得我们可以结合使用JSTL和message resource bundles,因此可以支持国际化。
springapp/war/WEB-INF/springapp-servlet.xml
| <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd"> <!-- - Application context definition for "springapp" DispatcherServlet. --> <beans> <bean id="springappController" class="SpringappController"/> <bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"> <property name="mappings"> <props> <prop key="/hello.htm">springappController</prop> </props> </property> </bean> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass"><value>org.springframework.web.servlet.view.JstlView</value></property> <property name="prefix"><value>/WEB-INF/jsp/</value></property> <property name="suffix"><value>.jsp</value></property> </bean> </beans> |
现在,我们就可以移出Controller中View名称的前缀和后缀了。
| springapp/src/SpringappController.java import org.springframework.web.servlet.mvc.Controller; import org.springframework.web.servlet.ModelAndView; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class SpringappController implements Controller { /** Logger for this class and subclasses */ protected final Log logger = LogFactory.getLog(getClass()); public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String now = (new java.util.Date()).toString(); logger.info("returning hello view with " + now); return new ModelAndView("hello", "now", now); } } |
这样修改后的例子应该仍能运行。
