[Java][华为云Java编程创造营][学习笔记][第三阶段][04_Java爬虫实战][二]

10，工具类Constants

package com.huawei.util; /* * 常量类 * */ public class Constants { //定义常量字符串 /* * BLOG_HOME：华为开发者论坛 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 / ，那么下方的头部就不要加上 / * */ public static final String ARTICLE_LIST_URI="/article/list/"; /* * 页面博客数量 * */ public static final double PAGE_SIZE=40.0; }

11，工具类JDBCUtils

package com.huawei.util; import java.io.IOException; import java.io.InputStream; import java.sql.*; import java.util.Properties; /* * JDBC工具类 * */ public class JDBCUtils { //创建全局属性 private static String className; private static String url; private static String username; private static String password; static { //加载配置文件，获取连接信息 Properties properties = new Properties(); try { InputStream in = JDBCUtils.class.getClassLoader().getResourceAsStream("db.properties"); //读取配置文件，获取信息 properties.load(in); //根据key获取value className = properties.getProperty("className"); url = properties.getProperty("url"); username = properties.getProperty("username"); password = properties.getProperty("password"); } catch (IOException e) { e.printStackTrace(); } } static { //加载驱动程序 try { Class.forName(className); } catch (ClassNotFoundException e) { e.printStackTrace(); } } //获取数据库连接对象 public static Connection getConn() { try { return DriverManager.getConnection(url, username, password); } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException("数据库连接错误！"); } } //关闭连接，释放资源 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(); } } } //方法重载 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; /*处理SQL，执行SQL*/ try { conn = getConn();//得到数据库连接 pstmt = conn.prepareStatement(preparedSql);//得到PreparedStatement对象 if (param != null) { for (int i = 0; i < param.length; i++) { pstmt.setObject(i + 1, param[i]);//为预编译sql设置参数 } } res = pstmt.executeQuery();//执行SQL语句 } 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;//主键 /*处理SQL，执行SQL*/ try { conn = getConn();//得到数据库连接 //注意：MySQL5.1.7需要显式添加一个参数Statement.RETURN_GENERATED_KEYS pstmt = conn.prepareStatement(preparedSql,Statement.RETURN_GENERATED_KEYS);//得到PreparedStatement对象 if (param != null) { for (int i = 0; i < param.length; i++) { pstmt.setObject(i + 1, param[i]);//为预编译SQL设置参数 } } pstmt.executeUpdate();//执行SQL语句 ResultSet resultSet = pstmt.getGeneratedKeys(); if (resultSet.next()) { key = resultSet.getInt(1);//获取主键返回 } } catch (SQLException e) { e.printStackTrace();//处理异常 } finally { JDBCUtils.closeAll(conn, pstmt); } return key; } }

12，工具类StringUtil

package com.huawei.util; /* * 字符串工具类 * */ public class StringUtil { /* * 博主id处理 * */ public static String subId(String url)//url为博客网址 { if (url != null && url.trim().length() != 0)//非空判断 { /*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，启动类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); //博主对象 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