附： 1. Parsing and traversing a Document 2. jsoup API
HtmlCommon.java
package common; import java.io.*; import java.net.HttpURLConnection; import java.net.URL; import java.util.Map; /** * Created by dell on 2017/7/31. */ public class HttpCommon { /** * 发送http请求 * * @param url url地址 * @param param post 参数 * @param type 请求的方式（主要是GET/POST） * @param encode 编码 * @param paramType 请求的数据类型（application/json，application/html，application/xml） * @return 返回 请求的数据结果 */ private static String submitUrlContent(String url, Map<String, String> param, String type, String encode, String paramType, String json) { String result = ""; String sparam = getUrl(param); if (!paramType.isEmpty() && paramType.toUpperCase() == "JSON") { sparam = json; } BufferedReader in = null; HttpURLConnection connection = null; try { URL realUrl = new URL(url); // 打开和URL之间的连接 connection = (HttpURLConnection) realUrl.openConnection(); // 设置通用的请求属性 connection.setRequestProperty("accept", "image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*"); connection.setRequestProperty("connection", "Keep-Alive"); connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)"); connection.setRequestProperty("Accept-Language", "zh-CN,zh;q=0.8"); connection.setRequestProperty("contentType", encode.toUpperCase()); connection.setDoOutput(true); connection.setDoInput(true); switch (paramType.toUpperCase()) { case "HTML": connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=" + encode.toUpperCase()); break; case "JSON": connection.setRequestProperty("Content-Type", "application/json;charset=" + encode.toUpperCase()); break; } connection.setRequestMethod(type.toUpperCase()); // 建立实际的连接 connection.connect(); // 获取所有响应头字段 OutputStreamWriter osw = new OutputStreamWriter(connection.getOutputStream(), encode.toLowerCase()); osw.write(sparam); osw.flush(); osw.close(); if (connection.getResponseCode() == 200) { in = new BufferedReader(new InputStreamReader(connection.getInputStream(), encode.toLowerCase())); String inputLine; while ((inputLine = in.readLine()) != null) { result += inputLine; } in.close(); } } catch (Exception e) { System.out.println("err"); } finally { if (connection != null) { connection.disconnect(); } } return result; } /** * 解析url后的参数 * * @param param 存储 map 的参数 * @return 返回解析出的字符串 */ private static String getUrl(Map<String, String> param) { String result = ""; if (param == null || param.size() == 0) { result = ""; } else { StringBuilder str = new StringBuilder(); for (Map.Entry<String, String> entry : param.entrySet()) { str.append("&" + entry.getKey() + "=" + entry.getValue()); } result = str.toString(); } return result; } /** * 发送HTTP GET请求 * * @param url 地址 * @param encode 编码 * @return 返回请求的数据结果 */ public static String getContentUrl(String url, String encode) { return submitUrlContent(url, null, "GET", encode, "HTML", ""); } /** * 发送HTTP POST请求 * * @param url URL地址 * @param encode 编码 * @param map 参数 * @return 返回请求的数据结果 */ public static String postContentUrl(String url, String encode, Map<String, String> map) { return submitUrlContent(url, map, "POST", encode, "HTML", ""); } /** * 发送HTTP POST json 请求 * * @param url 地址 * @param encode 编码 * @param json json数据 * @return 返回请求的数据值 */ public static String jsonContentUrl(String url, String encode, String json) { return submitUrlContent(url, null, "POST", encode, "JSON", json); } }JsoupCommon.java(要导入 jsoup.jar)
package common; import org.jsoup.Jsoup; import org.jsoup.nodes.Document; import org.jsoup.select.Elements; /** * @author lenovo * @date 2018/2/18 */ public class JsoupCommon { private Document doc = null; public Elements query(String htmlString, String expression) { Elements elements = null; doc= Jsoup.parse(htmlString); if (doc != null) { elements = doc.select(expression); } return elements; } }Test.java
package common; import org.jsoup.select.Elements; /** * * @author lenovo * @date 2018/2/18 */ public class Test { public static String getTitle() { String result = ""; String url = "https://baike.baidu.com/item/jsoup/9012509?fr=aladdin"; String htmlString = common.HttpCommon.getContentUrl(url, "utf-8"); JsoupCommon jsoup = new JsoupCommon(); Elements elements = jsoup.query(htmlString, "title"); result = elements.html(); return result; } }Main.java
/** * @author lenovo */ public class Main { public static void main(String[] args) { String title = common.Test.getTitle(); System.out.println("标题是：" + title); } }