使用Spring Boot构建Spring MVC应用程序

Question

我试图使用Spring Boot构建一个非常简单的Spring MVC应用程序。到现在为止，我所有的尝试都失败了这是移民：

WebConfig：

@SpringBootApplication
@ComponentScan("newTestProject")
public class WebConfig extends WebMvcConfigurerAdapter {

    public static void main(String[] args) throws Exception {
        SpringApplication.run(WebConfig.class, args);
    }

    @Bean
    public ViewResolver jspViewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");
        resolver.setExposeContextBeansAsAttributes(true);
        return resolver;
    }
}

WebAppInitializer：

@Configuration
public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class<?>[]{};
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class<?>[]{WebConfig.class};
    }
}

控制器：

@Controller
public class IndexController {

    @RequestMapping(value = "/")
    public String index() {
        return "index";
    }
}

POM：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>groupId</groupId>
    <artifactId>messagesAppHiber</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.2.RELEASE</version>
    </parent>

    <packaging>war</packaging>

    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>

</project>

控制台中没有错误消息：

2017-03-15 21:25:49.631  INFO 1192 --- [           main] newTestProject.config.WebConfig          : Starting WebConfig on Rafale-2-ПК with PID 1192 (D:\TEMP\untitled\target\classes started by Rafale-2 in D:\TEMP\untitled)
2017-03-15 21:25:49.633  INFO 1192 --- [           main] newTestProject.config.WebConfig          : No active profile set, falling back to default profiles: default
2017-03-15 21:25:49.702  INFO 1192 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@1188e820: startup date [Wed Mar 15 21:25:49 EET 2017]; root of context hierarchy
2017-03-15 21:25:51.122  INFO 1192 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2017-03-15 21:25:51.136  INFO 1192 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2017-03-15 21:25:51.137  INFO 1192 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.11
2017-03-15 21:25:51.248  INFO 1192 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2017-03-15 21:25:51.249  INFO 1192 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1549 ms
2017-03-15 21:25:51.393  INFO 1192 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2017-03-15 21:25:51.399  INFO 1192 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2017-03-15 21:25:51.399  INFO 1192 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2017-03-15 21:25:51.399  INFO 1192 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2017-03-15 21:25:51.399  INFO 1192 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2017-03-15 21:25:51.661  INFO 1192 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@1188e820: startup date [Wed Mar 15 21:25:49 EET 2017]; root of context hierarchy
2017-03-15 21:25:51.714  INFO 1192 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/]}" onto public java.lang.String newTestProject.controllers.IndexController.index()
2017-03-15 21:25:51.717  INFO 1192 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2017-03-15 21:25:51.717  INFO 1192 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2017-03-15 21:25:51.741  INFO 1192 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-03-15 21:25:51.741  INFO 1192 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-03-15 21:25:51.769  INFO 1192 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-03-15 21:25:51.941  INFO 1192 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2017-03-15 21:25:51.989  INFO 1192 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2017-03-15 21:25:51.992  INFO 1192 --- [           main] newTestProject.config.WebConfig          : Started WebConfig in 2.634 seconds (JVM running for 2.935)
2017-03-15 21:25:57.507  INFO 1192 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
2017-03-15 21:25:57.507  INFO 1192 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
2017-03-15 21:25:57.519  INFO 1192 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 12 ms

结果应该是我的浏览器中显示的index.jsp，而是我得到Whitelabel错误页面。这个配置有什么问题？

Answer 1

1）删除WebAppInitializer类 - 因为spring boot自动配置它所以不需要它。

2）删除web.xml。我不知道你有什么，但由于你正在使用注释配置，所以不需要它。

3）通过覆盖configureDefaultServletHandling中的WebConfig来启用默认servlet。

@Override
public void configureDefaultServletHandling(
        DefaultServletHandlerConfigurer configurer) {
    configurer.enable();
}

4）添加以下maven依赖项：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-jasper</artifactId>
    <scope>provided</scope>
</dependency>

5）使用maven运行项目

$ mvn clean spring-boot:run

PS：我不知道你的jsp文件中有什么。但是如果你使用普通的html，这种方法肯定会起作用。如果您正在使用某些jstl内容，则必须添加jstl依赖项

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
</dependency>