springmvc中的页面解析器ViewResolver不起作用,变量输出字符串的解决方案
<web-app xmlns:web="http://xmlns.jcp.org/xml/ns/javaee"> <servlet> <servlet-name>chapter2</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>chapter2</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>chapter2</servlet-name> <url-pattern>/hello</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>hello</welcome-file> </welcome-file-list> </web-app>
web.xml 配置
chapter2-servlet.xml 配置
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd" default-lazy-init="true"> <mvc:default-servlet-handler></mvc:default-servlet-handler> <context:component-scan base-package="cn.javass.chapter2.web.controller" /> <!-- HandlerMapping --> <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping" /> <!-- HandlerAdapter --> <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter" /> <!-- 处理器 --> <bean name="/hello" class="cn.javass.chapter2.web.controller.HelloWorldController" /> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!-- <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> --> <property name="prefix" value="/WEB-INF/jsp/" /> <property name="suffix" value=".jsp" /> </bean> </beans>
HelloWorldController
源码
package cn.javass.chapter2.web.controller; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; public class HelloWorldController implements Controller { @Override public ModelAndView handleRequest(HttpServletRequest arg0, HttpServletResponse arg1) throws Exception { // TODO Auto-generated method stub //1、收集参数、验证参数 //2、绑定参数到命令对象 //3、将命令对象传入业务对象进行业务处理 //4、选择下一个页面 ModelAndView mv = new ModelAndView(); //添加模型数据 可以是任意的POJO对象 mv.addObject("message", "Hello World!"); //设置逻辑视图名,视图解析器会根据该名字解析到具体的视图页面 mv.setViewName("hello"); return mv; } }
目录结构如下:
页面输出结果为:
${message} 居然是一个字符串,解析器没起作用
查了很多资料,有的人说这个问题很常见。一般来说,只要容器支持Servlet2.4就行。跟Spring和struts没关系。
在页面上部加上:
<%@ page isELIgnored="false"%>
但是不管用
我只需修改了项目名称就可以了!
不知道具体什么原因,后来发现web.xml被修改了
<?xml version="1.0" encoding="UTF-8"?> <!-- DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. Copyright 2000-2007 Sun Microsystems, Inc. All rights reserved. The contents of this file are subject to the terms of either the GNU General Public License Version 2 only ("GPL") or the Common Development and Distribution License("CDDL") (collectively, the "License"). You may not use this file except in compliance with the License. You can obtain a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific language governing permissions and limitations under the License. When distributing the software, include this License Header Notice in each file and include the License file at glassfish/bootstrap/legal/LICENSE.txt. Sun designates this particular file as subject to the "Classpath" exception as provided by Sun in the GPL Version 2 section of the License file that accompanied this code. If applicable, add the following below the License Header, with the fields enclosed by brackets [] replaced by your own identifying information: "Portions Copyrighted [year] [name of copyright owner]" Contributor(s): If you wish your version of this file to be governed by only the CDDL or only the GPL Version 2, indicate your decision by adding "[Contributor] elects to include this software in this distribution under the [CDDL or GPL Version 2] license." If you don't indicate a single choice of license, a recipient has the option to distribute your version of this file under either the CDDL, the GPL Version 2 or to extend the choice of license to its licensees as provided above. However, if you add GPL Version 2 code and therefore, elected the GPL Version 2 license, then the option applies only if the new code is made subject to such option by the copyright holder. --> <!-- This is the XML DTD for the Servlet 2.3 deployment descriptor. All Servlet 2.3 deployment descriptors must include a DOCTYPE of the following form: <!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd"> --> <!-- The following conventions apply to all J2EE deployment descriptor elements unless indicated otherwise. - In elements that contain PCDATA, leading and trailing whitespace in the data may be ignored. - In elements whose value is an "enumerated type", the value is case sensitive. - In elements that specify a pathname to a file within the same JAR file, relative filenames (i.e., those not starting with "/") are considered relative to the root of the JAR file's namespace. Absolute filenames (i.e., those starting with "/") also specify names in the root of the JAR file's namespace. In general, relative names are preferred. The exception is .war files where absolute names are preferred for consistency with the servlet API. --> <!-- The web-app element is the root of the deployment descriptor for a web application. --> <!-- The auth-constraint element indicates the user roles that should be permitted access to this resource collection. The role-name used here must either correspond to the role-name of one of the security-role elements defined for this web application, or be the specially reserved role-name "*" that is a compact syntax for indicating all roles in the web application. If both "*" and rolenames appear, the container interprets this as all roles. If no roles are defined, no user is allowed access to the portion of the web application described by the containing security-constraint. The container matches role names case sensitively when determining access. Used in: security-constraint --> <!-- The auth-method element is used to configure the authentication mechanism for the web application. As a prerequisite to gaining access to any web resources which are protected by an authorization constraint, a user must have authenticated using the configured mechanism. Legal values for this element are "BASIC", "DIGEST", "FORM", or "CLIENT-CERT". Used in: login-config --> <!-- The context-param element contains the declaration of a web application's servlet context initialization parameters. Used in: web-app --> <!-- The description element is used to provide text describing the parent element. The description element should include any information that the web application war file producer wants to provide to the consumer of the web application war file (i.e., to the Deployer). Typically, the tools used by the web application war file consumer will display the description when processing the parent element that contains the description. Used in: auth-constraint, context-param, ejb-local-ref, ejb-ref, env-entry, filter, init-param, resource-env-ref, resource-ref, run-as, security-role, security-role-ref, servlet, user-data-constraint, web-app, web-resource-collection --> <!-- The display-name element contains a short name that is intended to be displayed by tools. The display name need not be unique. Used in: filter, security-constraint, servlet, web-app Example: <display-name>Employee Self Service</display-name> --> <!-- The distributable element, by its presence in a web application deployment descriptor, indicates that this web application is programmed appropriately to be deployed into a distributed servlet container Used in: web-app --> <!-- The ejb-link element is used in the ejb-ref or ejb-local-ref elements to specify that an EJB reference is linked to an enterprise bean. The name in the ejb-link element is composed of a path name specifying the ejb-jar containing the referenced enterprise bean with the ejb-name of the target bean appended and separated from the path name by "#". The path name is relative to the war file containing the web application that is referencing the enterprise bean. This allows multiple enterprise beans with the same ejb-name to be uniquely identified. Used in: ejb-local-ref, ejb-ref Examples: <ejb-link>EmployeeRecord</ejb-link> <ejb-link>../products/product.jar#ProductEJB</ejb-link> --> <!-- The ejb-local-ref element is used for the declaration of a reference to an enterprise bean's local home. The declaration consists of: - an optional description - the EJB reference name used in the code of the web application that's referencing the enterprise bean - the expected type of the referenced enterprise bean - the expected local home and local interfaces of the referenced enterprise bean - optional ejb-link information, used to specify the referenced enterprise bean Used in: web-app --> <!-- The ejb-ref element is used for the declaration of a reference to an enterprise bean's home. The declaration consists of: - an optional description - the EJB reference name used in the code of the web application that's referencing the enterprise bean - the expected type of the referenced enterprise bean - the expected home and remote interfaces of the referenced enterprise bean - optional ejb-link information, used to specify the referenced enterprise bean Used in: web-app --> <!-- The ejb-ref-name element contains the name of an EJB reference. The EJB reference is an entry in the web application's environment and is relative to the java:comp/env context. The name must be unique within the web application. It is recommended that name is prefixed with "ejb/". Used in: ejb-local-ref, ejb-ref Example: <ejb-ref-name>ejb/Payroll</ejb-ref-name> --> <!-- The ejb-ref-type element contains the expected type of the referenced enterprise bean. The ejb-ref-type element must be one of the following: <ejb-ref-type>Entity</ejb-ref-type> <ejb-ref-type>Session</ejb-ref-type> Used in: ejb-local-ref, ejb-ref --> <!-- The env-entry element contains the declaration of a web application's environment entry. The declaration consists of an optional description, the name of the environment entry, and an optional value. If a value is not specified, one must be supplied during deployment. --> <!-- The env-entry-name element contains the name of a web applications's environment entry. The name is a JNDI name relative to the java:comp/env context. The name must be unique within a web application. Example: <env-entry-name>minAmount</env-entry-name> Used in: env-entry --> <!-- The env-entry-type element contains the fully-qualified Java type of the environment entry value that is expected by the web application's code. The following are the legal values of env-entry-type: java.lang.Boolean java.lang.Byte java.lang.Character java.lang.String java.lang.Short java.lang.Integer java.lang.Long java.lang.Float java.lang.Double Used in: env-entry --> <!-- The env-entry-value element contains the value of a web application's environment entry. The value must be a String that is valid for the constructor of the specified type that takes a single String parameter, or for java.lang.Character, a single character. Example: <env-entry-value>100.00</env-entry-value> Used in: env-entry --> <!-- The error-code contains an HTTP error code, ex: 404 Used in: error-page --> <!-- The error-page element contains a mapping between an error code or exception type to the path of a resource in the web application Used in: web-app --> <!-- The exception type contains a fully qualified class name of a Java exception type. Used in: error-page --> <!-- The extension element contains a string describing an extension. example: "txt" Used in: mime-mapping --> <!-- Declares a filter in the web application. The filter is mapped to either a servlet or a URL pattern in the filter-mapping element, using the filter-name value to reference. Filters can access the initialization parameters declared in the deployment descriptor at runtime via the FilterConfig interface. Used in: web-app --> <!-- The fully qualified classname of the filter. Used in: filter --> <!-- Declaration of the filter mappings in this web application. The container uses the filter-mapping declarations to decide which filters to apply to a request, and in what order. The container matches the request URI to a Servlet in the normal way. To determine which filters to apply it matches filter-mapping declarations either on servlet-name, or on url-pattern for each filter-mapping element, depending on which style is used. The order in which filters are invoked is the order in which filter-mapping declarations that match a request URI for a servlet appear in the list of filter-mapping elements.The filter-name value must be the value of the <filter-name> sub-elements of one of the <filter> declarations in the deployment descriptor. Used in: web-app --> <!-- The logical name of the filter. This name is used to map the filter. Each filter name is unique within the web application. Used in: filter, filter-mapping --> <!-- The form-error-page element defines the location in the web app where the error page that is displayed when login is not successful can be found. The path begins with a leading / and is interpreted relative to the root of the WAR. Used in: form-login-config --> <!-- The form-login-config element specifies the login and error pages that should be used in form based login. If form based authentication is not used, these elements are ignored. Used in: login-config --> <!-- The form-login-page element defines the location in the web app where the page that can be used for login can be found. The path begins with a leading / and is interpreted relative to the root of the WAR. Used in: form-login-config --> <!-- The home element contains the fully-qualified name of the enterprise bean's home interface. Used in: ejb-ref Example: <home>com.aardvark.payroll.PayrollHome</home> --> <!-- The http-method contains an HTTP method (GET | POST |...). Used in: web-resource-collection --> <!-- The icon element contains small-icon and large-icon elements that specify the file names for small and a large GIF or JPEG icon images used to represent the parent element in a GUI tool. Used in: filter, servlet, web-app --> <!-- The init-param element contains a name/value pair as an initialization param of the servlet Used in: filter, servlet --> <!-- The jsp-file element contains the full path to a JSP file within the web application beginning with a `/'. Used in: servlet --> <!-- The large-icon element contains the name of a file containing a large (32 x 32) icon image. The file name is a relative path within the web application's war file. The image may be either in the JPEG or GIF format. The icon can be used by tools. Used in: icon Example: <large-icon>employee-service-icon32x32.jpg</large-icon> --> <!-- The listener element indicates the deployment properties for a web application listener bean. Used in: web-app --> <!-- The listener-class element declares a class in the application must be registered as a web application listener bean. The value is the fully qualified classname of the listener class. Used in: listener --> <!-- The load-on-startup element indicates that this servlet should be loaded (instantiated and have its init() called) on the startup of the web application. The optional contents of these element must be an integer indicating the order in which the servlet should be loaded. If the value is a negative integer, or the element is not present, the container is free to load the servlet whenever it chooses. If the value is a positive integer or 0, the container must load and initialize the servlet as the application is deployed. The container must guarantee that servlets marked with lower integers are loaded before servlets marked with higher integers. The container may choose the order of loading of servlets with the same load-on-start-up value. Used in: servlet --> <!-- The local element contains the fully-qualified name of the enterprise bean's local interface. Used in: ejb-local-ref --> <!-- The local-home element contains the fully-qualified name of the enterprise bean's local home interface. Used in: ejb-local-ref --> <!-- The location element contains the location of the resource in the web application relative to the root of the web application. The value of the location must have a leading `/'. Used in: error-page --> <!-- The login-config element is used to configure the authentication method that should be used, the realm name that should be used for this application, and the attributes that are needed by the form login mechanism. Used in: web-app --> <!-- The mime-mapping element defines a mapping between an extension and a mime type. Used in: web-app --> <!-- The mime-type element contains a defined mime type. example: "text/plain" Used in: mime-mapping --> <!-- The param-name element contains the name of a parameter. Each parameter name must be unique in the web application. Used in: context-param, init-param --> <!-- The param-value element contains the value of a parameter. Used in: context-param, init-param --> <!-- The realm name element specifies the realm name to use in HTTP Basic authorization. Used in: login-config --> <!-- The remote element contains the fully-qualified name of the enterprise bean's remote interface. Used in: ejb-ref Example: <remote>com.wombat.empl.EmployeeService</remote> --> <!-- The res-auth element specifies whether the web application code signs on programmatically to the resource manager, or whether the Container will sign on to the resource manager on behalf of the web application. In the latter case, the Container uses information that is supplied by the Deployer. The value of this element must be one of the two following: <res-auth>Application</res-auth> <res-auth>Container</res-auth> Used in: resource-ref --> <!-- The res-ref-name element specifies the name of a resource manager connection factory reference. The name is a JNDI name relative to the java:comp/env context. The name must be unique within a web application. Used in: resource-ref --> <!-- The res-sharing-scope element specifies whether connections obtained through the given resource manager connection factory reference can be shared. The value of this element, if specified, must be one of the two following: <res-sharing-scope>Shareable</res-sharing-scope> <res-sharing-scope>Unshareable</res-sharing-scope> The default value is Shareable. Used in: resource-ref --> <!-- The res-type element specifies the type of the data source. The type is specified by the fully qualified Java language class or interface expected to be implemented by the data source. Used in: resource-ref --> <!-- The resource-env-ref element contains a declaration of a web application's reference to an administered object associated with a resource in the web application's environment. It consists of an optional description, the resource environment reference name, and an indication of the resource environment reference type expected by the web application code. Used in: web-app Example: <resource-env-ref> <resource-env-ref-name>jms/StockQueue</resource-env-ref-name> <resource-env-ref-type>javax.jms.Queue</resource-env-ref-type> </resource-env-ref> --> <!-- The resource-env-ref-name element specifies the name of a resource environment reference; its value is the environment entry name used in the web application code. The name is a JNDI name relative to the java:comp/env context and must be unique within a web application. Used in: resource-env-ref --> <!-- The resource-env-ref-type element specifies the type of a resource environment reference. It is the fully qualified name of a Java language class or interface. Used in: resource-env-ref --> <!-- The resource-ref element contains a declaration of a web application's reference to an external resource. It consists of an optional description, the resource manager connection factory reference name, the indication of the resource manager connection factory type expected by the web application code, the type of authentication (Application or Container), and an optional specification of the shareability of connections obtained from the resource (Shareable or Unshareable). Used in: web-app Example: <resource-ref> <res-ref-name>jdbc/EmployeeAppDB</res-ref-name> <res-type>javax.sql.DataSource</res-type> <res-auth>Container</res-auth> <res-sharing-scope>Shareable</res-sharing-scope> </resource-ref> --> <!-- The role-link element is a reference to a defined security role. The role-link element must contain the name of one of the security roles defined in the security-role elements. Used in: security-role-ref --> <!-- The role-name element contains the name of a security role. The name must conform to the lexical rules for an NMTOKEN. Used in: auth-constraint, run-as, security-role, security-role-ref --> <!-- The run-as element specifies the run-as identity to be used for the execution of the web application. It contains an optional description, and the name of a security role. Used in: servlet --> <!-- The security-constraint element is used to associate security constraints with one or more web resource collections Used in: web-app --> <!-- The security-role element contains the definition of a security role. The definition consists of an optional description of the security role, and the security role name. Used in: web-app Example: <security-role> <description> This role includes all employees who are authorized to access the employee service application. </description> <role-name>employee</role-name> </security-role> --> <!-- The security-role-ref element contains the declaration of a security role reference in the web application's code. The declaration consists of an optional description, the security role name used in the code, and an optional link to a security role. If the security role is not specified, the Deployer must choose an appropriate security role. The value of the role-name element must be the String used as the parameter to the EJBContext.isCallerInRole(String roleName) method or the HttpServletRequest.isUserInRole(String role) method. Used in: servlet --> <!-- The servlet element contains the declarative data of a servlet. If a jsp-file is specified and the load-on-startup element is present, then the JSP should be precompiled and loaded. Used in: web-app --> <!-- The servlet-class element contains the fully qualified class name of the servlet. Used in: servlet --> <!-- The servlet-mapping element defines a mapping between a servlet and a url pattern Used in: web-app --> <!-- The servlet-name element contains the canonical name of the servlet. Each servlet name is unique within the web application. Used in: filter-mapping, servlet, servlet-mapping --> <!-- The session-config element defines the session parameters for this web application. Used in: web-app --> <!-- The session-timeout element defines the default session timeout interval for all sessions created in this web application. The specified timeout must be expressed in a whole number of minutes. If the timeout is 0 or less, the container ensures the default behaviour of sessions is never to time out. Used in: session-config --> <!-- The small-icon element contains the name of a file containing a small (16 x 16) icon image. The file name is a relative path within the web application's war file. The image may be either in the JPEG or GIF format. The icon can be used by tools. Used in: icon Example: <small-icon>employee-service-icon16x16.jpg</small-icon> --> <!-- The taglib element is used to describe a JSP tag library. Used in: web-app --> <!-- the taglib-location element contains the location (as a resource relative to the root of the web application) where to find the Tag Libary Description file for the tag library. Used in: taglib --> <!-- The taglib-uri element describes a URI, relative to the location of the web.xml document, identifying a Tag Library used in the Web Application. Used in: taglib --> <!-- The transport-guarantee element specifies that the communication between client and server should be NONE, INTEGRAL, or CONFIDENTIAL. NONE means that the application does not require any transport guarantees. A value of INTEGRAL means that the application requires that the data sent between the client and server be sent in such a way that it can't be changed in transit. CONFIDENTIAL means that the application requires that the data be transmitted in a fashion that prevents other entities from observing the contents of the transmission. In most cases, the presence of the INTEGRAL or CONFIDENTIAL flag will indicate that the use of SSL is required. Used in: user-data-constraint --> <!-- The url-pattern element contains the url pattern of the mapping. Must follow the rules specified in Section 11.2 of the Servlet API Specification. Used in: filter-mapping, servlet-mapping, web-resource-collection --> <!-- The user-data-constraint element is used to indicate how data communicated between the client and container should be protected. Used in: security-constraint --> <!-- The web-resource-collection element is used to identify a subset of the resources and HTTP methods on those resources within a web application to which a security constraint applies. If no HTTP methods are specified, then the security constraint applies to all HTTP methods. Used in: security-constraint --> <!-- The web-resource-name contains the name of this web resource collection. Used in: web-resource-collection --> <!-- The welcome-file element contains file name to use as a default welcome file, such as index.html Used in: welcome-file-list --> <!-- The welcome-file-list contains an ordered list of welcome files elements. Used in: web-app --> <!-- The ID mechanism is to allow tools that produce additional deployment information (i.e., information beyond the standard deployment descriptor information) to store the non-standard information in a separate file, and easily refer from these tool-specific files to the information in the standard deployment descriptor. Tools are not allowed to add the non-standard information into the standard deployment descriptor. --> <web-app xmlns:web="http://xmlns.jcp.org/xml/ns/javaee"> <servlet> <servlet-name>chapter2</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>chapter2</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>chapter2</servlet-name> <url-pattern>/hello</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>hello</welcome-file> </welcome-file-list> </web-app>