Java 爬虫 CSDN

Java 版的爬虫 爬取 CSDN 搜索韩顺平的文章

这个是爬虫下的结果，结果为 txt 可以使用 poi 生成到 excel 文件 具体我就不讲解了

万物皆可爬（Java 万能的）

本文项目使用 Spring Boot 搭建 普通 Maven 项目亦可！！！

先看一下结果吧（不爬取广告栏）：

这个是 CSDN 官网的数据：

主要使用的是 jsoup 进行爬虫，英语比较好的话建议还是看下官方的文档 = =

这个是项目搭建结构

下载工具,包含各种类型的请求 Client.java

package com.niu.req.downloader;


import org.apache.http.NameValuePair;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.*;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.springframework.util.StringUtils;

import java.io.UnsupportedEncodingException;
import java.util.*;

/**
 * @Description 下载工具，包含各种类型的请求
 */
public class Client {

    // 编码格式。发送编码格式统一用UTF-8
    private static final String ENCODING = "UTF-8";

    // 设置连接超时时间，单位毫秒。
    private static final int CONNECT_TIMEOUT = 60000;

    // 请求获取数据的超时时间(即响应时间)，单位毫秒。
    private static final int SOCKET_TIMEOUT = 60000;

    public static Page doRequest(Request request) throws Exception {

        HttpRequestBase http = null;

        switch (request.getMethod()) {
            case POST:
                http = new HttpPost(request.getUrl());
                break;
            case GET:
            default:
                http = new HttpGet(request.getUrl());
                break;

        }

        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(CONNECT_TIMEOUT)
                .setSocketTimeout(SOCKET_TIMEOUT).build();

        http.setConfig(requestConfig);

        if (request.getHeaders() != null && !request.getHeaders().isEmpty()) {
            packageHeader(request.getHeaders(), http);
        }

        if (http instanceof HttpPost && request.getParams() != null) {
            packageParam(request.getParams(), (HttpPost) http);
        }


        Page page = Page.build(request);

        // 执行请求并获得响应结果
        try (final CloseableHttpClient httpClient = HttpClients.custom().build();
             final CloseableHttpResponse httpResponse = httpClient.execute(http)
        ) {
            if (httpResponse != null
                    && !StringUtils.isEmpty(httpResponse.getStatusLine())
                    && httpResponse.getEntity() != null
            ) {

                String content = EntityUtils.toString(httpResponse.getEntity(), ENCODING);
                page.setStatusCode(httpResponse.getStatusLine().getStatusCode());
                page.setRaw(content);

            }
        }

        return page;
    }


    /**
     * Description: 封装请求头
     *
     * @param params
     * @param httpMethod
     */
    private static void packageHeader(final Map<String, String> params, final HttpRequestBase httpMethod) {
        if (params == null || params.isEmpty()) {
            return;
        }

        params.entrySet().stream().forEach(e -> {
            httpMethod.setHeader(e.getKey(), e.getValue());
        });
    }

    /**
     * Description: 封装请求参数
     *
     * @param params
     * @param httpMethod
     * @throws UnsupportedEncodingException
     */
    private static void packageParam(final Map<String, String> params, final HttpEntityEnclosingRequestBase httpMethod)
            throws UnsupportedEncodingException {

        if (params == null || params.isEmpty()) {
            return;
        }

        final List<NameValuePair> nvps = new ArrayList<NameValuePair>();
        params.entrySet().stream().forEach(e -> {
            nvps.add(new BasicNameValuePair(e.getKey(), e.getValue()));
        });

        httpMethod.setEntity(new UrlEncodedFormEntity(nvps, ENCODING));
    }


}

Constant.java Http 请求的一些常用参数

package com.niu.req.downloader;

import lombok.AllArgsConstructor;
import lombok.Getter;

/**
 * @Description http 请求的一些常用参数
 */
public class Constant {

    @Getter
    @AllArgsConstructor
    public enum Method {
        GET("GET"),POST("POST");
        String code;
    }

    @Getter
    @AllArgsConstructor
    public enum StatusCode {
        CODE_200(200),CODE_404(404),CODE_503(503),CODE_500(500);
        Integer code;

    }

    @Getter
    @AllArgsConstructor
    public enum Header {
        REFERER("Referer"),USER_AGENT("User-Agent");
        String code;
    }
}

Page.java 页面实体

package com.niu.req.downloader;

import lombok.Getter;
import lombok.Setter;

/**
 * @Description TODO
 */
@Getter
@Setter
public class Page {

    private Request request;

    private Integer statusCode = Constant.StatusCode.CODE_500.getCode();

    private String raw;

    private Page(){ }

    public static Page build(Request request){
        Page page = new Page();
        page.setRequest(request);

        return page;
    }
}

Request.java 封装请求实体类

package com.niu.req.downloader;

import lombok.Getter;
import lombok.Setter;

import java.util.Map;

/**
 * @Description TODO
 */
@Setter
@Getter
public class Request {

    public Request(String url){
        this.url = url;
    }

    private Constant.Method method = Constant.Method.GET;

    private String url;

    private Map<String,String> headers;

    private Map<String,String> params;

}

Request.java 测试类

package com.niu.req.course01;

import com.niu.req.downloader.Client;
import com.niu.req.downloader.Page;
import com.niu.req.downloader.Request;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

/**
 * @Description 主要爬CSDN 搜索韩顺平后页面的所有文章
 */
public class RequestTest {

    public static void main(String[] args) throws Exception {
        Request request = new Request("https://so.csdn.net/so/search/s.do?q=%E9%9F%A9%E9%A1%BA%E5%B9%B3&t=%20&u=");  // url 路径

        Page page = Client.doRequest(request);

        Document parse = Jsoup.parse(page.getRaw()); //得到Html文本

        Elements select = parse.select("div.search-list-con"); //获取要得到的节点

        select.forEach( e -> {
            Elements data = e.select("dl.search-list.J_search");  // 再找到节点下的节点
            if (data == null || data.isEmpty()) {
                return;
            }
            for (Element datum : data) {
                System.out.println(datum.text());// 得到text
            }
        });
    }
}

搭建结束 运行 Request.java 即可