java实现爬虫常用的第三方包：

• httpclient，for http
• jsoup，for dom
• rhino，for js
• jackson，for json

pom.xml摘录

<dependencies>

        <!-- simulate web browser -->
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.7</version>
        </dependency>

        <!-- parse DOM -->
        <dependency>
            <groupId>org.jsoup</groupId>
            <artifactId>jsoup</artifactId>
            <version>1.11.3</version>
        </dependency>

        <!-- jackson -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.8</version>
        </dependency>

        <!-- parse javascript -->
        <dependency>
            <groupId>org.mozilla</groupId>
            <artifactId>rhino</artifactId>
            <version>1.7.10</version>
        </dependency>

        <!-- simulate client action -->
        <dependency>
            <groupId>net.sourceforge.htmlunit</groupId>
            <artifactId>htmlunit</artifactId>
            <version>2.33</version>
        </dependency>

        <!-- upgrade junit to junit4 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12<!-- default is v3.8.1 --></version>
            <scope>test</scope>
        </dependency>

        <!-- log -->
        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.25</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-log4j12 -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.25</version>
            <!-- <scope>test</scope> -->
        </dependency>

    </dependencies>

启用log4j基本配置，在main方法中加入语句：

public static void main(String[] args) {

    //启用log4j基本配置
    //不想去写配置文件，可以用Java基本配置
    BasicConfigurator.configure();
    //...
}