springboot整合servlet两种方式

小咪咪 2022-05-11 02:38 217阅读 0赞

## springboot与servlet整合的两种方式： ##

### 1. 方式一： ###

**项目结构：**

![70][]

**pom.xml:**

<?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.lucifer.springboot</groupId>
        <artifactId>springboot-servlet</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <packaging>jar</packaging>
    
        <name>springboot-servlet</name>
        <description>Demo project for Spring Boot</description>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.0.5.RELEASE</version>
            <relativePath/> 
        </parent>
    
        <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.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    
    </project>

** SpringbootServletApplication : springboot项目的启动类**

package com.lucifer.springboot;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.web.servlet.ServletComponentScan;
    
    
    /**
     * @ServletComponentScan
     * 在springboot启动时会扫描@WebServlet，并将该类实例化
     */
    @SpringBootApplication
    @ServletComponentScan
    public class SpringbootServletApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(SpringbootServletApplication.class, args);
        }
    }

**`FirstServet：`**

![70 1][]

**启动项目，浏览器输入localhost:8080/first:**

![70 2][]

**ps: 整合过程中新手很容易遇坑的地方:原本我的项目结构是这样的，如下图：**

![70 3][]

**这时候启动项目，控制台无报错，浏览器输入地址，404，原因就是因为com.lucifer.springboot.servlet这个包没有扫描到。**

** 那百度了，按照百度查到的资料，加了扫描包的注解，没用，效果依然凉凉。**

![70 4][]

**因此这里就把启动类放在com.lucifer.springboot包下，FirstServet就包在子包com.lucifer.springboot.servlet下，启动类的扫描默认是扫描与该启动类同包以及其子包下的类。**

### 2.方式二： ###

**项目结构：**

![70 5][]

**SecondServlet :**

package com.lucifer.springboot.servlet;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    
    /**
     * @author: Lucifer
     * @create: 2018-09-19 14:39
     * @description:
     **/
    public class SecondServlet extends HttpServlet {
    
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
            resp.setCharacterEncoding("utf-8");
            resp.setContentType("text/html;charset=utf-8");
            resp.getWriter().append("springboot整合servlet成功");
        }
    }

**`SpringbootServletApplication：`**

package com.lucifer.springboot;
    
    import com.lucifer.springboot.servlet.SecondServlet;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.web.servlet.ServletRegistrationBean;
    import org.springframework.context.annotation.Bean;
    
    
    
    @SpringBootApplication
    public class SpringbootServletApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(SpringbootServletApplication.class, args);
        }
    
        @Bean
        public ServletRegistrationBean getservletRegistrationBean(){
            ServletRegistrationBean bean=new ServletRegistrationBean(new SecondServlet());
            bean.addUrlMappings("/second");
            return bean;
        }
    
    }

![70 6][]

[70]: /images/20220511/f2d32c0309954a08b7b8a2739179ed11.png
[70 1]: /images/20220511/e178ce2caa964690a5614adf67dee57f.png
[70 2]: /images/20220511/4f1ad8e847054f78a5afbe43b6a145b0.png
[70 3]: /images/20220511/1302e06f34864987a8cc4d067cf0fc7c.png
[70 4]: /images/20220511/ebb0dcc36aac47659cbe3f0d6a083bf8.png
[70 5]: /images/20220511/5855ea6e945442299e7072069f57de82.png
[70 6]: /images/20220511/6fb670361a1a4e299cf060648c37661d.png