【Java Web开发学习】Spring MVC 开始配置

时间:2023-03-08 17:03:44

Spring MVC 开始配置

转载:http://www.cnblogs.com/yangchongxing/p/8871370.htm

学习搭建最简单的Spring MVC框架。

===============================================================l

目录

  1. Java配置方式
  2. Xml配置方式

================================================================

Jar包下载地址:http://repo.spring.io/release/org/springframework/spring/4.3.9.RELEASE/spring-framework-4.3.9.RELEASE-dist.zip

新建动态web工程ycxfw(名字根据实际情况定), 复制下面的jar到WebContent\WEB-INF\lib目录

commons-logging-1.2.jar
spring-aop-4.3.9.RELEASE.jar
spring-aspects-4.3.9.RELEASE.jar
spring-beans-4.3.9.RELEASE.jar
spring-context-4.3.9.RELEASE.jar
spring-context-support-4.3.9.RELEASE.jar
spring-core-4.3.9.RELEASE.jar
spring-expression-4.3.9.RELEASE.jar
spring-instrument-4.3.9.RELEASE.jar
spring-jdbc-4.3.9.RELEASE.jar
spring-jms-4.3.9.RELEASE.jar
spring-messaging-4.3.9.RELEASE.jar
spring-orm-4.3.9.RELEASE.jar
spring-oxm-4.3.9.RELEASE.jar
spring-test-4.3.9.RELEASE.jar
spring-tx-4.3.9.RELEASE.jar
spring-web-4.3.9.RELEASE.jar
spring-webmvc-4.3.9.RELEASE.jar
spring-websocket-4.3.9.RELEASE.jar

1、基于Java配置(推荐)

借助Servlet3规范和Spring3.1,我们可以不用web.xml就能配置DispatchServlet

package cn.ycx.web.config;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class ServletWebApplicationInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
protected Class<?>[] getRootConfigClasses() {
return new Class<?>[] {RootConfig.class}; //ContextLoaderListener上下文配置
} @Override
protected Class<?>[] getServletConfigClasses() {
return new Class<?>[] {ServletConfig.class}; //DispatcherServlet上下文配置
} @Override
protected String[] getServletMappings() {
return new String[]{"/"}; //将DispatcherServlet映射到 /
} }
package cn.ycx.web.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.context.annotation.ComponentScan.Filter; @Configuration
@ComponentScan(
basePackages = {"cn.ycx.web"},
// 排除掉
excludeFilters = {@Filter( type=FilterType.ANNOTATION, value={org.springframework.stereotype.Controller.class} )}
)
public class RootConfig { }
package cn.ycx.web.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.context.annotation.ComponentScan.Filter;
import org.springframework.context.support.ResourceBundleMessageSource;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver; @Configuration
@EnableWebMvc
@ComponentScan(
basePackages = {"cn.ycx.web.controller"},
// 仅仅扫描
includeFilters = {@Filter( type=FilterType.ANNOTATION, value={org.springframework.stereotype.Controller.class} )}
)
public class ServletConfig extends WebMvcConfigurerAdapter {
/**
* 配置JSP视图解析器
* @return
*/
@Bean
public ViewResolver viewResolver() {
InternalResourceViewResolver resolver = new InternalResourceViewResolver();
resolver.setPrefix("/WEB-INF/views");
resolver.setSuffix(".jsp");
resolver.setExposeContextBeansAsAttributes(true);
return resolver;
}
/**
* 配置静态文件处理
*/
@Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
configurer.enable();
}
}

新建WebContent\WEB-INF\views\test\index.jsp文件

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
Test page index jsp
</body>
</html>

启动tomcat服务器访问,http://127.0.0.1:8080/ycxfw/test/index。

到此代码已经写完了。

@Configuration 注解表示该bean是一个配置文件,Spring自动加载其中的bean

@EnableWebMvc 注解表示启用Spring Mvc

@ComponentScan 注解表示自动扫描要装配的bean,basePackages是要扫描的目录,默认扫描配置文件所在的包及子包;includeFilters 包含过滤,excludeFilters 排除过滤

ServletConfig配置Spring MVC相关的bean(相当于DispatcherServlet的配置),RootConfig配置spring相关的bean(相当于ContextLoaderListener的配置

有同学可能对没有web.xml文件而疑惑,我们来说说原因。

javax.servlet.ServletContainerInitializer是Servlet 3.0 新增的一个接口类,容器在启动时使用JAR Service API来发现ServletContainerInitializer的实现类,并且容器将WEB-INF/lib目录下JAR包中的类都交给该类的onStartup()方法处理,我们通常需要在该实现类上使用 @HandlesTypes 注解来指定希望被处理的类,过滤掉不希望给 onStartup()处理的类。

* Licensed to the Apache Software Foundation (ASF) under one or more
package javax.servlet; import java.util.Set; /**
* ServletContainerInitializers (SCIs) are registered via an entry in the
* file META-INF/services/javax.servlet.ServletContainerInitializer that must be
* included in the JAR file that contains the SCI implementation.
* <p>
* SCI processing is performed regardless of the setting of metadata-complete.
* SCI processing can be controlled per JAR file via fragment ordering. If an
* absolute ordering is defined, the only those JARs included in the ordering
* will be processed for SCIs. To disable SCI processing completely, an empty
* absolute ordering may be defined.
* <p>
* SCIs register an interest in annotations (class, method or field) and/or
* types via the {@link javax.servlet.annotation.HandlesTypes} annotation which
* is added to the class.
*
* @since Servlet 3.0
*/
public interface ServletContainerInitializer { /**
* Receives notification during startup of a web application of the classes
* within the web application that matched the criteria defined via the
* {@link javax.servlet.annotation.HandlesTypes} annotation.
*
* @param c The (possibly null) set of classes that met the specified
* criteria
* @param ctx The ServletContext of the web application in which the
* classes were discovered
*
* @throws ServletException If an error occurs
*/
void onStartup(Set<Class<?>> c, ServletContext ctx) throws ServletException;
}

也就是说容器自动发现实现ServletContainerInitializer接口的类,如果能发现的话,就会用它来配置Servlet容器,Spring提供了这个接口的实现 SpringServletContainerInitializer

/*
* Copyright 2002-2016 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/ package org.springframework.web; import java.lang.reflect.Modifier;
import java.util.LinkedList;
import java.util.List;
import java.util.ServiceLoader;
import java.util.Set;
import javax.servlet.ServletContainerInitializer;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.HandlesTypes; import org.springframework.core.annotation.AnnotationAwareOrderComparator; /**
* Servlet 3.0 {@link ServletContainerInitializer} designed to support code-based
* configuration of the servlet container using Spring's {@link WebApplicationInitializer}
* SPI as opposed to (or possibly in combination with) the traditional
* {@code web.xml}-based approach.
*
* <h2>Mechanism of Operation</h2>
* This class will be loaded and instantiated and have its {@link #onStartup}
* method invoked by any Servlet 3.0-compliant container during container startup assuming
* that the {@code spring-web} module JAR is present on the classpath. This occurs through
* the JAR Services API {@link ServiceLoader#load(Class)} method detecting the
* {@code spring-web} module's {@code META-INF/services/javax.servlet.ServletContainerInitializer}
* service provider configuration file. See the
* <a href="http://download.oracle.com/javase/6/docs/technotes/guides/jar/jar.html#Service%20Provider">
* JAR Services API documentation</a> as well as section <em>8.2.4</em> of the Servlet 3.0
* Final Draft specification for complete details.
*
* <h3>In combination with {@code web.xml}</h3>
* A web application can choose to limit the amount of classpath scanning the Servlet
* container does at startup either through the {@code metadata-complete} attribute in
* {@code web.xml}, which controls scanning for Servlet annotations or through an
* {@code <absolute-ordering>} element also in {@code web.xml}, which controls which
* web fragments (i.e. jars) are allowed to perform a {@code ServletContainerInitializer}
* scan. When using this feature, the {@link SpringServletContainerInitializer}
* can be enabled by adding "spring_web" to the list of named web fragments in
* {@code web.xml} as follows:
*
* <pre class="code">
* {@code
* <absolute-ordering>
* <name>some_web_fragment</name>
* <name>spring_web</name>
* </absolute-ordering>
* }</pre>
*
* <h2>Relationship to Spring's {@code WebApplicationInitializer}</h2>
* Spring's {@code WebApplicationInitializer} SPI consists of just one method:
* {@link WebApplicationInitializer#onStartup(ServletContext)}. The signature is intentionally
* quite similar to {@link ServletContainerInitializer#onStartup(Set, ServletContext)}:
* simply put, {@code SpringServletContainerInitializer} is responsible for instantiating
* and delegating the {@code ServletContext} to any user-defined
* {@code WebApplicationInitializer} implementations. It is then the responsibility of
* each {@code WebApplicationInitializer} to do the actual work of initializing the
* {@code ServletContext}. The exact process of delegation is described in detail in the
* {@link #onStartup onStartup} documentation below.
*
* <h2>General Notes</h2>
* In general, this class should be viewed as <em>supporting infrastructure</em> for
* the more important and user-facing {@code WebApplicationInitializer} SPI. Taking
* advantage of this container initializer is also completely <em>optional</em>: while
* it is true that this initializer will be loaded and invoked under all Servlet 3.0+
* runtimes, it remains the user's choice whether to make any
* {@code WebApplicationInitializer} implementations available on the classpath. If no
* {@code WebApplicationInitializer} types are detected, this container initializer will
* have no effect.
*
* <p>Note that use of this container initializer and of {@code WebApplicationInitializer}
* is not in any way "tied" to Spring MVC other than the fact that the types are shipped
* in the {@code spring-web} module JAR. Rather, they can be considered general-purpose
* in their ability to facilitate convenient code-based configuration of the
* {@code ServletContext}. In other words, any servlet, listener, or filter may be
* registered within a {@code WebApplicationInitializer}, not just Spring MVC-specific
* components.
*
* <p>This class is neither designed for extension nor intended to be extended.
* It should be considered an internal type, with {@code WebApplicationInitializer}
* being the public-facing SPI.
*
* <h2>See Also</h2>
* See {@link WebApplicationInitializer} Javadoc for examples and detailed usage
* recommendations.<p>
*
* @author Chris Beams
* @author Juergen Hoeller
* @author Rossen Stoyanchev
* @since 3.1
* @see #onStartup(Set, ServletContext)
* @see WebApplicationInitializer
*/
@HandlesTypes(WebApplicationInitializer.class)
public class SpringServletContainerInitializer implements ServletContainerInitializer { /**
* Delegate the {@code ServletContext} to any {@link WebApplicationInitializer}
* implementations present on the application classpath.
* <p>Because this class declares @{@code HandlesTypes(WebApplicationInitializer.class)},
* Servlet 3.0+ containers will automatically scan the classpath for implementations
* of Spring's {@code WebApplicationInitializer} interface and provide the set of all
* such types to the {@code webAppInitializerClasses} parameter of this method.
* <p>If no {@code WebApplicationInitializer} implementations are found on the classpath,
* this method is effectively a no-op. An INFO-level log message will be issued notifying
* the user that the {@code ServletContainerInitializer} has indeed been invoked but that
* no {@code WebApplicationInitializer} implementations were found.
* <p>Assuming that one or more {@code WebApplicationInitializer} types are detected,
* they will be instantiated (and <em>sorted</em> if the @{@link
* org.springframework.core.annotation.Order @Order} annotation is present or
* the {@link org.springframework.core.Ordered Ordered} interface has been
* implemented). Then the {@link WebApplicationInitializer#onStartup(ServletContext)}
* method will be invoked on each instance, delegating the {@code ServletContext} such
* that each instance may register and configure servlets such as Spring's
* {@code DispatcherServlet}, listeners such as Spring's {@code ContextLoaderListener},
* or any other Servlet API componentry such as filters.
* @param webAppInitializerClasses all implementations of
* {@link WebApplicationInitializer} found on the application classpath
* @param servletContext the servlet context to be initialized
* @see WebApplicationInitializer#onStartup(ServletContext)
* @see AnnotationAwareOrderComparator
*/
@Override
public void onStartup(Set<Class<?>> webAppInitializerClasses, ServletContext servletContext)
throws ServletException { List<WebApplicationInitializer> initializers = new LinkedList<WebApplicationInitializer>(); if (webAppInitializerClasses != null) {
for (Class<?> waiClass : webAppInitializerClasses) {
// Be defensive: Some servlet containers provide us with invalid classes,
// no matter what @HandlesTypes says...
if (!waiClass.isInterface() && !Modifier.isAbstract(waiClass.getModifiers()) &&
WebApplicationInitializer.class.isAssignableFrom(waiClass)) {
try {
initializers.add((WebApplicationInitializer) waiClass.newInstance());
}
catch (Throwable ex) {
throw new ServletException("Failed to instantiate WebApplicationInitializer class", ex);
}
}
}
} if (initializers.isEmpty()) {
servletContext.log("No Spring WebApplicationInitializer types detected on classpath");
return;
} servletContext.log(initializers.size() + " Spring WebApplicationInitializers detected on classpath");
AnnotationAwareOrderComparator.sort(initializers);
for (WebApplicationInitializer initializer : initializers) {
initializer.onStartup(servletContext);
}
} }

这个类又会反过来查找实现WebApplicationInitializer的类并将配置的任务交给他们来完成。

我们来看看继承关系,我们自己的类ServletWebApplicationInitializer

继承AbstractAnnotationConfigDispatcherServletInitializer继承AbstractDispatcherServletInitializer继承AbstractContextLoaderInitializer继承WebApplicationInitializer

/*
* Copyright 2002-2012 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/ package org.springframework.web; import javax.servlet.ServletContext;
import javax.servlet.ServletException; /**
* Interface to be implemented in Servlet 3.0+ environments in order to configure the
* {@link ServletContext} programmatically -- as opposed to (or possibly in conjunction
* with) the traditional {@code web.xml}-based approach.
*
* <p>Implementations of this SPI will be detected automatically by {@link
* SpringServletContainerInitializer}, which itself is bootstrapped automatically
* by any Servlet 3.0 container. See {@linkplain SpringServletContainerInitializer its
* Javadoc} for details on this bootstrapping mechanism.
*
* <h2>Example</h2>
* <h3>The traditional, XML-based approach</h3>
* Most Spring users building a web application will need to register Spring's {@code
* DispatcherServlet}. For reference, in WEB-INF/web.xml, this would typically be done as
* follows:
* <pre class="code">
* {@code
* <servlet>
* <servlet-name>dispatcher</servlet-name>
* <servlet-class>
* org.springframework.web.servlet.DispatcherServlet
* </servlet-class>
* <init-param>
* <param-name>contextConfigLocation</param-name>
* <param-value>/WEB-INF/spring/dispatcher-config.xml</param-value>
* </init-param>
* <load-on-startup>1</load-on-startup>
* </servlet>
*
* <servlet-mapping>
* <servlet-name>dispatcher</servlet-name>
* <url-pattern>/</url-pattern>
* </servlet-mapping>}</pre>
*
* <h3>The code-based approach with {@code WebApplicationInitializer}</h3>
* Here is the equivalent {@code DispatcherServlet} registration logic,
* {@code WebApplicationInitializer}-style:
* <pre class="code">
* public class MyWebAppInitializer implements WebApplicationInitializer {
*
* @Override
* public void onStartup(ServletContext container) {
* XmlWebApplicationContext appContext = new XmlWebApplicationContext();
* appContext.setConfigLocation("/WEB-INF/spring/dispatcher-config.xml");
*
* ServletRegistration.Dynamic dispatcher =
* container.addServlet("dispatcher", new DispatcherServlet(appContext));
* dispatcher.setLoadOnStartup(1);
* dispatcher.addMapping("/");
* }
*
* }</pre>
*
* As an alternative to the above, you can also extend from {@link
* org.springframework.web.servlet.support.AbstractDispatcherServletInitializer}.
*
* As you can see, thanks to Servlet 3.0's new {@link ServletContext#addServlet} method
* we're actually registering an <em>instance</em> of the {@code DispatcherServlet}, and
* this means that the {@code DispatcherServlet} can now be treated like any other object
* -- receiving constructor injection of its application context in this case.
*
* <p>This style is both simpler and more concise. There is no concern for dealing with
* init-params, etc, just normal JavaBean-style properties and constructor arguments. You
* are free to create and work with your Spring application contexts as necessary before
* injecting them into the {@code DispatcherServlet}.
*
* <p>Most major Spring Web components have been updated to support this style of
* registration. You'll find that {@code DispatcherServlet}, {@code FrameworkServlet},
* {@code ContextLoaderListener} and {@code DelegatingFilterProxy} all now support
* constructor arguments. Even if a component (e.g. non-Spring, other third party) has not
* been specifically updated for use within {@code WebApplicationInitializers}, they still
* may be used in any case. The Servlet 3.0 {@code ServletContext} API allows for setting
* init-params, context-params, etc programmatically.
*
* <h2>A 100% code-based approach to configuration</h2>
* In the example above, {@code WEB-INF/web.xml} was successfully replaced with code in
* the form of a {@code WebApplicationInitializer}, but the actual
* {@code dispatcher-config.xml} Spring configuration remained XML-based.
* {@code WebApplicationInitializer} is a perfect fit for use with Spring's code-based
* {@code @Configuration} classes. See @{@link
* org.springframework.context.annotation.Configuration Configuration} Javadoc for
* complete details, but the following example demonstrates refactoring to use Spring's
* {@link org.springframework.web.context.support.AnnotationConfigWebApplicationContext
* AnnotationConfigWebApplicationContext} in lieu of {@code XmlWebApplicationContext}, and
* user-defined {@code @Configuration} classes {@code AppConfig} and
* {@code DispatcherConfig} instead of Spring XML files. This example also goes a bit
* beyond those above to demonstrate typical configuration of the 'root' application
* context and registration of the {@code ContextLoaderListener}:
* <pre class="code">
* public class MyWebAppInitializer implements WebApplicationInitializer {
*
* @Override
* public void onStartup(ServletContext container) {
* // Create the 'root' Spring application context
* AnnotationConfigWebApplicationContext rootContext =
* new AnnotationConfigWebApplicationContext();
* rootContext.register(AppConfig.class);
*
* // Manage the lifecycle of the root application context
* container.addListener(new ContextLoaderListener(rootContext));
*
* // Create the dispatcher servlet's Spring application context
* AnnotationConfigWebApplicationContext dispatcherContext =
* new AnnotationConfigWebApplicationContext();
* dispatcherContext.register(DispatcherConfig.class);
*
* // Register and map the dispatcher servlet
* ServletRegistration.Dynamic dispatcher =
* container.addServlet("dispatcher", new DispatcherServlet(dispatcherContext));
* dispatcher.setLoadOnStartup(1);
* dispatcher.addMapping("/");
* }
*
* }</pre>
*
* As an alternative to the above, you can also extend from {@link
* org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer}.
*
* Remember that {@code WebApplicationInitializer} implementations are <em>detected
* automatically</em> -- so you are free to package them within your application as you
* see fit.
*
* <h2>Ordering {@code WebApplicationInitializer} execution</h2>
* {@code WebApplicationInitializer} implementations may optionally be annotated at the
* class level with Spring's @{@link org.springframework.core.annotation.Order Order}
* annotation or may implement Spring's {@link org.springframework.core.Ordered Ordered}
* interface. If so, the initializers will be ordered prior to invocation. This provides
* a mechanism for users to ensure the order in which servlet container initialization
* occurs. Use of this feature is expected to be rare, as typical applications will likely
* centralize all container initialization within a single {@code WebApplicationInitializer}.
*
* <h2>Caveats</h2>
*
* <h3>web.xml versioning</h3>
* <p>{@code WEB-INF/web.xml} and {@code WebApplicationInitializer} use are not mutually
* exclusive; for example, web.xml can register one servlet, and a {@code
* WebApplicationInitializer} can register another. An initializer can even
* <em>modify</em> registrations performed in {@code web.xml} through methods such as
* {@link ServletContext#getServletRegistration(String)}. <strong>However, if
* {@code WEB-INF/web.xml} is present in the application, its {@code version} attribute
* must be set to "3.0" or greater, otherwise {@code ServletContainerInitializer}
* bootstrapping will be ignored by the servlet container.</strong>
*
* <h3>Mapping to '/' under Tomcat</h3>
* <p>Apache Tomcat maps its internal {@code DefaultServlet} to "/", and on Tomcat versions
* &lt;= 7.0.14, this servlet mapping <em>cannot be overridden programmatically</em>.
* 7.0.15 fixes this issue. Overriding the "/" servlet mapping has also been tested
* successfully under GlassFish 3.1.<p>
*
* @author Chris Beams
* @since 3.1
* @see SpringServletContainerInitializer
* @see org.springframework.web.context.AbstractContextLoaderInitializer
* @see org.springframework.web.servlet.support.AbstractDispatcherServletInitializer
* @see org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer
*/
public interface WebApplicationInitializer { /**
* Configure the given {@link ServletContext} with any servlets, filters, listeners
* context-params and attributes necessary for initializing this web application. See
* examples {@linkplain WebApplicationInitializer above}.
* @param servletContext the {@code ServletContext} to initialize
* @throws ServletException if any call against the given {@code ServletContext}
* throws a {@code ServletException}
*/
void onStartup(ServletContext servletContext) throws ServletException; }

所以在容器启动时就会自动找到我们的初始化类ServletWebApplicationInitializer

@Configuration 注解特别说明

我们要是有多个配置文件,他们之间如何相互引用呢?答案就是使用@Import注解,比如我们有DataSourceConfig配置,想要在RootConfig配置中引用,代码如下。

package cn.ycx.config;

import javax.sql.DataSource;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ComponentScan.Filter;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.context.annotation.Import;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.multipart.MultipartResolver;
import org.springframework.web.multipart.support.StandardServletMultipartResolver; @Configuration
@ComponentScan(basePackages = {"cn.ycx"}, excludeFilters = {
@Filter( type=FilterType.ANNOTATION, value=org.springframework.stereotype.Controller.class)
})
@Import(DataSourceConfig.class) //引用其他配置中的Bean
public class RootConfig {
@Bean
public MultipartResolver multipartResolver() {
System.out.println("multipartResolver...");
return new StandardServletMultipartResolver();
}
@Bean
public JdbcTemplate jdbcTemplate(DataSource dataSource) {
System.out.println("jdbcTemplate...");
return new JdbcTemplate(dataSource);
}
}
package cn.ycx.config;

import javax.naming.NamingException;
import javax.sql.DataSource; import org.springframework.context.annotation.Bean;
import org.springframework.jndi.JndiObjectFactoryBean; public class DataSourceConfig {
@Bean
public DataSource dataSource() throws IllegalArgumentException, NamingException {
System.out.println("dataSource...");
JndiObjectFactoryBean jndi = new JndiObjectFactoryBean();
jndi.setJndiName("jdbc/mysql");
jndi.setResourceRef(true);//自动添加 java:comp/env/ 前缀
jndi.setProxyInterface(javax.sql.DataSource.class);
jndi.afterPropertiesSet();
return (DataSource) jndi.getObject();
}
}

注意DataSourceConfig没有加@Configuration注解

 2、Xml配置方式

这种方式很简单,主要是配置web.xml和servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
<display-name>web</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<context-param>
<param-name>spring.profiles.default</param-name>
<param-value>dev</param-value>
</context-param>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>\WEB-INF\context.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>ds</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>\WEB-INF\servlet.xml</param-value>
</init-param>
<init-param>
<param-name>spring.profiles.default</param-name>
<param-value>dev</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>ds</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
<?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:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:c="http://www.springframework.org/schema/c"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd"> <mvc:annotation-driven></mvc:annotation-driven>
<context:component-scan base-package="cn.ycx"></context:component-scan>
<mvc:default-servlet-handler />
<!-- 会加载所有的properties文件 -->
<context:property-placeholder/>
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver"
p:prefix="/WEB-INF/views" p:suffix=".jsp"></bean>
</beans>

剩下的就是编写控制器