Spring Boot + WebMagic 实现网页爬虫，写得太好了！

来源：www.jianshu.com/ p/cfead4b3e34e

1.添加maven依赖
2.项目配置文件 application.properties
3.数据库表结构
4.实体类
5.mapper接口
6.CrawlerMapper.xml文件
7.XXX页面内容处理类XXXPageProcessor
8.XXX数据处理类XXXPipeline
9.爬虫任务类XXXTask
10.Spring boot程序启动类

WebMagic是一个开源的java爬虫框架。

WebMagic框架的使用并不是本文的重点，具体如何使用请参考官方文档：http://webmagic.io/docs/。

本文是对spring boot+WebMagic+MyBatis做了整合，使用WebMagic爬取数据，然后通过MyBatis持久化爬取的数据到mysql数据库。

本文提供的源代码可以作为java爬虫项目的脚手架。

1.添加maven依赖

<?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>hyzx</groupId> 
    <artifactId>qbasic-crawler</artifactId> 
    <version>1.0.0</version>

    <parent> 
        <groupId>org.springframework.boot</groupId> 
        <artifactId>spring-boot-starter-parent</artifactId> 
        <version>1.5.21.RELEASE</version> 
        <relativePath/> <!-- lookup parent from repository --> 
    </parent>

    <properties> 
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 
        <maven.test.skip>true</maven.test.skip> 
        <java.version>1.8</java.version> 
        <maven.compiler.plugin.version>3.8.1</maven.compiler.plugin.version> 
        <maven.resources.plugin.version>3.1.0</maven.resources.plugin.version>

        <mysql.connector.version>5.1.47</mysql.connector.version> 
        <druid.spring.boot.starter.version>1.1.17</druid.spring.boot.starter.version> 
        <mybatis.spring.boot.starter.version>1.3.4</mybatis.spring.boot.starter.version> 
        <fastjson.version>1.2.58</fastjson.version> 
        <commons.lang3.version>3.9</commons.lang3.version> 
        <joda.time.version>2.10.2</joda.time.version> 
        <webmagic.core.version>0.7.3</webmagic.core.version> 
    </properties>

    <dependencies> 
        <dependency> 
            <groupId>org.springframework.boot</groupId> 
            <artifactId>spring-boot-devtools</artifactId> 
            <scope>runtime</scope> 
            <optional>true</optional> 
        </dependency>

        <dependency> 
            <groupId>org.springframework.boot</groupId> 
            <artifactId>spring-boot-starter-test</artifactId> 
            <scope>test</scope> 
        </dependency>

        <dependency> 
            <groupId>org.springframework.boot</groupId> 
            <artifactId>spring-boot-configuration-processor</artifactId> 
            <optional>true</optional> 
        </dependency>

        <dependency> 
            <groupId>mysql</groupId> 
            <artifactId>mysql-connector-java</artifactId> 
            <version>${mysql.connector.version}</version> 
        </dependency>

        <dependency> 
            <groupId>com.alibaba</groupId> 
            <artifactId>druid-spring-boot-starter</artifactId> 
            <version>${druid.spring.boot.starter.version}</version> 
        </dependency>

        <dependency> 
            <groupId>org.mybatis.spring.boot</groupId> 
            <artifactId>mybatis-spring-boot-starter</artifactId> 
            <version>${mybatis.spring.boot.starter.version}</version> 
        </dependency>

        <dependency> 
            <groupId>com.alibaba</groupId> 
            <artifactId>fastjson</artifactId> 
            <version>${fastjson.version}</version> 
        </dependency>

        <dependency> 
            <groupId>org.apache.commons</groupId> 
            <artifactId>commons-lang3</artifactId> 
            <version>${commons.lang3.version}</version> 
        </dependency>

        <dependency> 
            <groupId>joda-time</groupId> 
            <artifactId>joda-time</artifactId> 
            <version>${joda.time.version}</version> 
        </dependency>

        <dependency> 
            <groupId>us.codecraft</groupId> 
            <artifactId>webmagic-core</artifactId> 
            <version>${webmagic.core.version}</version> 
            <exclusions> 
                <exclusion> 
                    <groupId>org.slf4j</groupId> 
                    <artifactId>slf4j-log4j12</artifactId> 
                </exclusion> 
            </exclusions> 
        </dependency> 
    </dependencies>

    <build> 
        <plugins> 
            <plugin> 
                <groupId>org.apache.maven.plugins</groupId> 
                <artifactId>maven-compiler-plugin</artifactId> 
                <version>${maven.compiler.plugin.version}</version> 
                <configuration> 
                    <source>${java.version}</source> 
                    <target>${java.version}</target> 
                    <encoding>${project.build.sourceEncoding}</encoding> 
                </configuration> 
            </plugin>

            <plugin> 
                <groupId>org.apache.maven.plugins</groupId> 
                <artifactId>maven-resources-plugin</artifactId> 
                <version>${maven.resources.plugin.version}</version> 
                <configuration> 
                    <encoding>${project.build.sourceEncoding}</encoding> 
                </configuration> 
            </plugin>

            <plugin> 
                <groupId>org.springframework.boot</groupId> 
                <artifactId>spring-boot-maven-plugin</artifactId> 
                <configuration> 
                    <fork>true</fork> 
                    <addResources>true</addResources> 
                </configuration> 
                <executions> 
                    <execution> 
                        <goals> 
                            <goal>repackage</goal> 
                        </goals> 
                    </execution> 
                </executions> 
            </plugin> 
        </plugins> 
    </build>

    <repositories> 
        <repository> 
            <id>public</id> 
            <name>aliyun nexus</name> 
            <url>http://maven.aliyun.com/nexus/content/groups/public/</url> 
            <releases> 
                <enabled>true</enabled> 
            </releases> 
        </repository> 
    </repositories>

    <pluginRepositories> 
        <pluginRepository> 
            <id>public</id> 
            <name>aliyun nexus</name> 
            <url>http://maven.aliyun.com/nexus/content/groups/public/</url> 
            <releases> 
                <enabled>true</enabled> 
            </releases> 
            <snapshots> 
                <enabled>false</enabled> 
            </snapshots> 
        </pluginRepository> 
    </pluginRepositories>
</project>

推荐下自己做的 Spring Boot 的实战项目： https://github.com/YunaiV/ruoyi-vue-pro

2.项目配置文件 application.properties

配置mysql数据源，druid数据库连接池以及MyBatis的mapper文件的位置。

> 推荐下自己做的 Spring Cloud 的实战项目：
>
> <https://github.com/YunaiV/onemall>

# mysql数据源配置
spring.datasource.name=mysql
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://192.168.0.63:3306/gjhzjl?useUnicode=true&characterEncoding=utf8&useSSL=false&allowMultiQueries=true
spring.datasource.username=root
spring.datasource.password=root

# druid数据库连接池配置
spring.datasource.druid.initial-size=5
spring.datasource.druid.min-idle=5
spring.datasource.druid.max-active=10
spring.datasource.druid.max-wait=60000
spring.datasource.druid.validation-query=SELECT 1 FROM DUAL
spring.datasource.druid.test-on-borrow=false
spring.datasource.druid.test-on-return=false
spring.datasource.druid.test-while-idle=true
spring.datasource.druid.time-between-eviction-runs-millis=60000
spring.datasource.druid.min-evictable-idle-time-millis=300000
spring.datasource.druid.max-evictable-idle-time-millis=600000

# mybatis配置
mybatis.mapperLocations=classpath:mapper/**/*.xml

3.数据库表结构

CREATE TABLE `cms_content` (
  `contentId` varchar(40) NOT NULL COMMENT '内容ID',
  `title` varchar(150) NOT NULL COMMENT '标题',
  `content` longtext COMMENT '文章内容',
  `releaseDate` datetime NOT NULL COMMENT '发布日期',
  PRIMARY KEY (`contentId`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='CMS内容表';

4.实体类

import java.util.Date;

public class CmsContentPO {
    private String contentId;

    private String title;

    private String content;

    private Date releaseDate;

    public String getContentId() {
        return contentId;
    }

    public void setContentId(String contentId) {
        this.contentId = contentId;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }

    public Date getReleaseDate() {
        return releaseDate;
    }

    public void setReleaseDate(Date releaseDate) {
        this.releaseDate = releaseDate;
    }
}

5.mapper接口

public interface CrawlerMapper {
    int addCmsContent(CmsContentPO record);
}

6.CrawlerMapper.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hyzx.qbasic.dao.CrawlerMapper">

    <insert id="addCmsContent" parameterType="com.hyzx.qbasic.model.CmsContentPO">
        insert into cms_content (contentId,
                                 title,
                                 releaseDate,
                                 content)
        values (#{contentId,jdbcType=VARCHAR},
                #{title,jdbcType=VARCHAR},
                #{releaseDate,jdbcType=TIMESTAMP},
                #{content,jdbcType=LONGVARCHAR})
    </insert>
</mapper>

7.XXX页面内容处理类XXXPageProcessor

主要用于解析爬取到的XXX html页面。

@Component
public class XXXPageProcessor implements PageProcessor {

    private Site site = Site.me().setRetryTimes(3).setSleepTime(1000);

    @Override 
    public void process(Page page) {
        page.addTargetRequests(page.getHtml().links().regex("https://www\\.xxx\\.com/question/\\d+/answer/\\d+.*").all());
        page.putField("title", page.getHtml().xpath("//h1[@class='QuestionHeader-title']/text()").toString());
        page.putField("answer", page.getHtml().xpath("//div[@class='QuestionAnswer-content']/tidyText()").toString());
        if (page.getResultItems().get("title") == null) {
            // 如果是列表页，跳过此页，pipeline不进行后续处理
            page.setSkip(true);
        }
    }

    @Override 
    public Site getSite() {
        return site;
    }
}

8.XXX数据处理类XXXPipeline

主要用于将XXX html页面解析出的数据存储到mysql数据库。

@Component
public class XXXPipeline implements Pipeline {
    private static final Logger LOGGER = LoggerFactory.getLogger(XXXPipeline.class);

    @Autowired 
    private CrawlerMapper crawlerMapper;

    public void process(ResultItems resultItems, Task task) {
        String title = resultItems.get("title");
        String answer = resultItems.get("answer");

        CmsContentPO contentPO = new CmsContentPO();
        contentPO.setContentId(UUID.randomUUID().toString());
        contentPO.setTitle(title);
        contentPO.setReleaseDate(new Date());
        contentPO.setContent(answer);

        try {
            boolean success = crawlerMapper.addCmsContent(contentPO) > 0;
            LOGGER.info("保存文章成功：{}", title);
        } catch (Exception ex) {
            LOGGER.error("保存文章失败", ex);
        }
    }
}

9.爬虫任务类XXXTask

每十分钟启动一次爬虫。

@Component
public class XXXTask {
    private static final Logger LOGGER = LoggerFactory.getLogger(XXXPipeline.class);

    @Autowired 
    private XXXPipeline XXXPipeline;

    @Autowired 
    private XXXPageProcessor xxxPageProcessor;

    private ScheduledExecutorService timer = Executors.newSingleThreadScheduledExecutor();

    public void crawl() {
        // 定时任务，每10分钟爬取一次
        timer.scheduleWithFixedDelay(() -> {
            Thread.currentThread().setName("xxxCrawlerThread");

            try {
                Spider.create(xxxPageProcessor)
                        // 从https://www.xxx.com/explore开始抓
                        .addUrl("https://www.xxx.com/explore")
                        // 抓取到的数据存数据库
                        .addPipeline(xxxPipeline)
                        // 开启2个线程抓取
                        .thread(2)
                        // 异步启动爬虫
                        .start();
            } catch (Exception ex) {
                LOGGER.error("定时抓取数据线程执行异常", ex);
            }
        }, 0, 10, TimeUnit.MINUTES);
    }
}

10.Spring boot程序启动类

@SpringBootApplication
@MapperScan(basePackages = "com.hyzx.qbasic.dao")
public class Application implements CommandLineRunner {

    @Autowired 
    private XXXTask xxxTask;

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

    @Override 
    public void run(String... strings) throws Exception {
        // 爬取数据
        xxxTask.crawl();
    }
}