idea搭建Spring环境-全注解无需web.xml
首先要创建Maven Web项目,不需要web.xml,如果有的话直接删除。
特别注意:Spring在整合其他组件的时候,如果其他组件已引入了一些Spring的jar包(如spring-data-mongodb),要注意与项目使用的主版本最好一致,不然会因为依赖冲突导致一些奇奇怪怪的错误,如IMPORT_BEAN_NAME_GENERATOR。
所以选择组件版本不是越高越好,适合的就好(你要么就提高Spring版本,但是风险较大)。
pom添加依赖
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<spring.version>5.0.2.RELEASE</spring.version>
<jackson.version>2.11.4</jackson.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
<!--Jackson-->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${jackson.version}</version>
</dependency>
</dependencies>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.5</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<!--因为没有web.xml,所以打成war包的时候需要忽略掉,否则会提示没有web.xml-->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.6</version>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
Spring上下文配置
tomcat启动时会自动扫描继承AbstractAnnotationConfigDispatcherServletInitializer的文件,所以这个文件是整个项目的程序入口,在这里可以配置根容器、Spring MVC容器,拦截请求等。
import org.springframework.web.filter.CharacterEncodingFilter;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
import javax.servlet.Filter;
/**
* @Description 整个项目的程序入口
*/
public class SpringContainer extends AbstractAnnotationConfigDispatcherServletInitializer {
/**
* 根容器,用于获取Spring应用容器的配置文件
*
* @return
*/
@Override
protected Class<?>[] getRootConfigClasses() {
//return new Class[0];
return new Class[]{RootConfig.class};
}
/**
* Spring mvc容器,是根容器的子容器
*
* @return
*/
@Override
protected Class<?>[] getServletConfigClasses() {
//return new Class[0];
return new Class[]{WebConfig.class};
}
/**
* "/"表示由DispatcherServlet处理所有向该应用发起的请求。
*
* @return
*/
@Override
protected String[] getServletMappings() {
//return new String[0];
return new String[]{"/"};
}
@Override
protected Filter[] getServletFilters() {
CharacterEncodingFilter characterEncodingFilter = new CharacterEncodingFilter();
characterEncodingFilter.setEncoding("UTF-8");
characterEncodingFilter.setForceEncoding(true);
return new Filter[]{characterEncodingFilter, characterEncodingFilter};
}
}
RootConfig类
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import org.springframework.context.annotation.FilterType;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RestController;
@Configuration
/**
* @EnableAspectJAutoProxy:开启AOP代理自动配置
* proxyTargetClass=true:表示使用CGLib动态代理技术织入增强,决定是基于接口的还是基于类的代理被创建。默认为false(JDK代理)
* 即<aop:aspectj-autoproxy proxy-target-class="true"/>
* */
@EnableAspectJAutoProxy(proxyTargetClass = true) //解决实现接口后,spring不能创建类实例的问题
@ComponentScan(
basePackages = {"com.harvey"},
excludeFilters = {//设置不扫描的文件,这里会排除Controller
@ComponentScan.Filter(type = FilterType.ANNOTATION, value = RestController.class),
@ComponentScan.Filter(type = FilterType.ANNOTATION, value = Controller.class)
}
)
public class RootConfig {
}
WebConfig类
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
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.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import java.util.ArrayList;
import java.util.List;
/**
* @Description Spring MVC 配置
*/
@Configuration
@EnableWebMvc //启用Spring MVC组件
@ComponentScan("com.yyds.base.controller") //配置扫描的ctrl层
public class WebConfig implements WebMvcConfigurer {
@Override
public void configureViewResolvers(ViewResolverRegistry registry) {
registry.viewResolver(viewResolver());
}
/**
* 配置静态资源的处理
*
* @param configurer
*/
@Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
//把针对静态资源的请求转交给servlet容器的default servlet处理
configurer.enable();
}
/**
* Jackson配置
* 添加自定义转换器
*/
@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
converters.add(mappingJackson2HttpMessageConverter());
}
@Override
public void addViewControllers(ViewControllerRegistry registry) {
//访问/hello/index,直接跳转到/WEB-INF/pages/index.jsp页面
registry.addViewController("/hello/index2").setViewName("index");
}
/**
* Jackson配置
*
* @return
*/
@Bean
public MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter() {
MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
List<MediaType> supportedMediaTypes = new ArrayList<MediaType>();
//MediaType mediaType1 = new MediaType("application\\json");
//MediaType mediaType2 = new MediaType("charset=UTF-8");
//supportedMediaTypes.add(mediaType1);
//supportedMediaTypes.add(mediaType2);
supportedMediaTypes = MediaType.parseMediaTypes("application/json; charset=utf-8");
converter.setSupportedMediaTypes(supportedMediaTypes);
return converter;
}
/**
* 配置JSP视图解析器
*
* @return
*/
@Bean
public ViewResolver viewResolver() {
InternalResourceViewResolver resolver = new InternalResourceViewResolver();
resolver.setPrefix("/WEB-INF/pages/");
resolver.setSuffix(".jsp");
//可以在JSP页面中通过${}访问beans
resolver.setExposeContextBeansAsAttributes(true);
return resolver;
}
}
注:Spring也提供了一个类AnnotationConfigApplicationContext,我们可以手动创建Spring容器
Spring环境验证
HelloController类
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
@RequestMapping("/hello")
public class HelloController {
/**
* 直接返回字符串
*
* @param name
* @return
*/
@GetMapping("/say")
@ResponseBody
public String sayChinese(String name) {
return "hello " + name;
}
/**
* 跳转页面
*
* @return
*/
@GetMapping("/index")
public String index() {
return "index";
}
}
WEB-INF/pages/index.jsp
<html>
<body>
<h2>Hello World!</h2>
</body>
</html>
使用Tomcat进行项目发布,访问http://localhost:8080/hello/index或http://localhost:8080/hello/index2