实现自己的ServletContainerInitializer

ServletContainerInitializer 也是 Servlet 3.0 新增的一个接口，容器在启动时使用 JAR 服务 API(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。

 

测试ServletContainerInitializer接口

第一步：创建maven项目、删除掉web.xml文件

第二步：修改pom.xml

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.lc</groupId>
  <artifactId>servlet</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>servlet Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.0.1</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>jsp-api</artifactId>
        <version>2.1</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>
  
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
  <build>
    <finalName>servlet3</finalName>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-war-plugin</artifactId>
            <version>2.4</version>
            <configuration>
                <failOnMissingWebXml>false</failOnMissingWebXml>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.0</version>
            <configuration>
                <source>1.6</source>
                <target>1.6</target>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.14</version>
            <configuration>
                <junitArtifactName>junit:junit</junitArtifactName>
                <includes>
                    <include>**/*Tests.java</include>
                </includes>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-eclipse-plugin</artifactId>
            <version>2.9</version>
            <configuration>
                <downloadSources>true</downloadSources>
                <downloadJavadocs>false</downloadJavadocs>
                <wtpversion>2.0</wtpversion>
            </configuration>
        </plugin>
    </plugins>
  </build>
</project>

第三步：实现ServletContainerInitializer接口

package com.lc.servlet;

import java.util.Set;

import javax.servlet.ServletContainerInitializer;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;

public class MyServletContainerInitializer implements ServletContainerInitializer {

    public void onStartup(Set<Class<?>> c, ServletContext ctx)
            throws ServletException {
        System.out.println("----------------------------------MyServletContainerInitializer----------------------------");
    }

}

第四步：添加

 

第五步：启动

一个简单的例子完成了