【小家Spring】Spring注解驱动开发---Servlet 3.0整合Spring MVC（不使用web.xml部署描述符，使用ServletContainerInitializer）（上）

<?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>com.fsx</groupId>
    <artifactId>demo-war</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.0.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <scope>provided</scope>
            <version>1.18.4</version>
        </dependency>
        <!-- 记录log日志  logback-core并不需要显示导入-->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>
        <!-- Spring MVC自动数据封装依赖的包  否则可能出现下面的错误，若使用@RequestBody的时候 -->
        <!-- Content type 'application/json' not supported 当然还有其余配置,原理了解-->
        <!-- 此处需要导入databind包即可， jackson-annotations、jackson-core都不需要显示自己的导入了-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.8</version>
        </dependency>
        <!-- fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.57</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <!-- 该插件是为了没有web.xml情况下，打war包。编译不要报错 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.6</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
            <!-- 编译环境在1.8编译 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.0</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                    <compilerVersion>${java.version}</compilerVersion>
                    <encoding>${project.build.sourceEncoding}</encoding>
                </configuration>
            </plugin>
        </plugins>
       <!--
            directory：属性指定资源文件放置的目录。
            includes：包含哪些配置文件（.class文件不用写）
            filtering：如果设置为false的话，则表示上文的filters配置失效；如果设置为true，则会根据${env}.properties里面的键值对来
                       填充includes指定文件里的${xxxx}占位符（若不做环境区分，一般就是false即可）
        -->
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                    <include>**/*.tld</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
    </build>
</project>

<configuration scan="true" scanPeriod="60 seconds" debug="false">
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
        </encoder>
    </appender>
    <root level="INFO">
        <appender-ref ref="STDOUT"/>
    </root>
</configuration>

/**
 * @author fangshixiang
 * @description
 * @date 2019-02-16 22:04
 */
@WebServlet(urlPatterns = "/hello")
public class HelloServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("hello servlet...");
    }
}

//容器启动的时候会将@HandlesTypes指定的这个类型下面的子类（实现类，子接口等）传递过来；
@HandlesTypes(value = {HelloService.class})
public class MyServletContainerInitializer implements ServletContainerInitializer {
    /**
     * 应用启动的时候，会运行onStartup方法；
     * <p>
     * Set<Class<?>> c：感兴趣的类型的所有子类型；
     * ServletContext ctx:代表当前Web应用的ServletContext；一个Web应用一个ServletContext；
     * <p>
     */
    @Override
    public void onStartup(Set<Class<?>> c, ServletContext ctx) throws ServletException {
      //这里的c会把所有我们感兴趣的类型都拿到
        System.out.println("感兴趣的类型：");
        for (Class<?> claz : c) {
            System.out.println(claz);
        }
    //==========================编码形式注册三大组件============================
        注册组件  ServletRegistration  
        //ServletRegistration.Dynamic servlet = ctx.addServlet("userServlet", new UserServlet());
        配置servlet的映射信息
        //servlet.addMapping("/user");
        //
        注册Listener
        //ctx.addListener(UserListener.class);
        //
        注册Filter  FilterRegistration
        //FilterRegistration.Dynamic filter = ctx.addFilter("userFilter", UserFilter.class);
        配置Filter的映射信息
        //filter.addMappingForUrlPatterns(EnumSet.of(DispatcherType.REQUEST), true, "/*");
    }
}