[Java][華為云Java編程創造營][學習筆記][第三階段][04_Java爬蟲實戰][二]

10，工具類Constants

package com.huawei.util; /* * 常量類 * */ public class Constants { //定義常量字符串 /* * BLOG_HOME：華為開發者論壇 https://hwdevelopers.blog.csdn.net/ * */ public static final String BLOG_HOME="https://hwdevelopers.blog.csdn.net"; /* * 博客文章列表拼接url，注意：如果BLOG_HOME的尾部加上了 / ，那么下方的頭部就不要加上 / * */ public static final String ARTICLE_LIST_URI="/article/list/"; /* * 頁面博客數量 * */ public static final double PAGE_SIZE=40.0; }

11，工具類JDBCUtils

package com.huawei.util; import java.io.IOException; import java.io.InputStream; import java.sql.*; import java.util.Properties; /* * JDBC工具類 * */ public class JDBCUtils { //創建全局屬性 private static String className; private static String url; private static String username; private static String password; static { //加載配置文件，獲取連接信息 Properties properties = new Properties(); try { InputStream in = JDBCUtils.class.getClassLoader().getResourceAsStream("db.properties"); //讀取配置文件，獲取信息 properties.load(in); //根據key獲取value className = properties.getProperty("className"); url = properties.getProperty("url"); username = properties.getProperty("username"); password = properties.getProperty("password"); } catch (IOException e) { e.printStackTrace(); } } static { //加載驅動程序 try { Class.forName(className); } catch (ClassNotFoundException e) { e.printStackTrace(); } } //獲取數據庫連接對象 public static Connection getConn() { try { return DriverManager.getConnection(url, username, password); } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException("數據庫連接錯誤！"); } } //關閉連接，釋放資源 public static void closeAll(Connection conn, Statement stat, ResultSet rs) { if (rs != null) { try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } } if (stat != null) { try { stat.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } //方法重載 public static void closeAll(Connection conn, PreparedStatement pstmt) { if (pstmt != null) { try { pstmt.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } public static ResultSet executeQuery(String preparedSql, Object... param) { Connection conn = null; PreparedStatement pstmt = null; ResultSet res = null; /*處理SQL，執行SQL*/ try { conn = getConn();//得到數據庫連接 pstmt = conn.prepareStatement(preparedSql);//得到PreparedStatement對象 if (param != null) { for (int i = 0; i < param.length; i++) { pstmt.setObject(i + 1, param[i]);//為預編譯sql設置參數 } } res = pstmt.executeQuery();//執行SQL語句 } catch (SQLException e) { e.printStackTrace(); } finally { JDBCUtils.closeAll(conn, pstmt, res); } return res; } public static int executeUpdate(String preparedSql, Object... param) { Connection conn = null; PreparedStatement pstmt = null; int key = 0;//主鍵 /*處理SQL，執行SQL*/ try { conn = getConn();//得到數據庫連接 //注意：MySQL5.1.7需要顯式添加一個參數Statement.RETURN_GENERATED_KEYS pstmt = conn.prepareStatement(preparedSql,Statement.RETURN_GENERATED_KEYS);//得到PreparedStatement對象 if (param != null) { for (int i = 0; i < param.length; i++) { pstmt.setObject(i + 1, param[i]);//為預編譯SQL設置參數 } } pstmt.executeUpdate();//執行SQL語句 ResultSet resultSet = pstmt.getGeneratedKeys(); if (resultSet.next()) { key = resultSet.getInt(1);//獲取主鍵返回 } } catch (SQLException e) { e.printStackTrace();//處理異常 } finally { JDBCUtils.closeAll(conn, pstmt); } return key; } }

12，工具類StringUtil

package com.huawei.util; /* * 字符串工具類 * */ public class StringUtil { /* * 博主id處理 * */ public static String subId(String url)//url為博客網址 { if (url != null && url.trim().length() != 0)//非空判斷 { /*int index = url.lastIndexOf("/");//切割博主id String id = url.substring(index + 1); return id;*/ int index1=url.indexOf("https://"); int index2 = url.indexOf("."); String id = url.substring(index1, index2); id = id.replace("https://", ""); return id; } else { return ""; } } }

13，啟動類Main

package com; import com.huawei.entity.Article; import com.huawei.entity.Blogger; import com.huawei.entity.Picture; import com.huawei.util.BlogUtil; import com.huawei.util.Constants; import com.huawei.util.JDBCUtils; import com.huawei.util.StringUtil; import java.util.List; public class Main { public static String insertBlogger = "insert into t_blogger(id,article_count,page_count) value(?,?,?)"; public static String insertArticle = "insert into t_article(b_id,url,create_time,title) value(?,?,?,?)"; public static String insertPicture = "insert into t_picture(a_id,url) value(?,?)"; public static void main(String[] args) { int articleCount = BlogUtil.getArticleCount(Constants.BLOG_HOME); int pageCount = BlogUtil.getArticlePageCount(articleCount); //博主對象 Blogger blogger = new Blogger(StringUtil.subId(Constants.BLOG_HOME), articleCount, pageCount); System.out.println(blogger); JDBCUtils.executeUpdate(insertBlogger, blogger.getId(), blogger.getArticleCount(), blogger.getPageCount()); //文章列表 List