update some fields of one database of mysql using the contents of some other fields by selecting the same database

InfoUpdate.java

import java.util.Date;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class InfoUpdate {
	private static String url = "jdbc:mysql://localhost:3306/Yourdatabase";
	private static String user = "Yourusername";
	private static String password = "Yourpassword";
	private static Connection conn;
	private static Connection update_conn;
	private static PreparedStatement ps;
	private static PreparedStatement update_ps;
	private static ResultSet rs;
	private static String select_sql;
	private static String update_sql;
	static {
		try {
			Class.forName("com.mysql.jdbc.Driver");
		} catch (ClassNotFoundException e) {
			throw new ExceptionInInitializerError(e);
		}
	}

	public static Connection getConnection() throws SQLException {
		return DriverManager.getConnection(url, user, password);
	}

	public static void free(ResultSet rs, Statement st, Connection conn) {
		try {
			if (rs != null)
				rs.close();
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			try {
				if (st != null)
					st.close();
			} catch (SQLException e) {
				e.printStackTrace();
			} finally {
				if (conn != null)
					try {
						conn.close();
					} catch (SQLException e) {
						e.printStackTrace();
					}
			}
		}
	}
	private static void doUpdate(String kind, String prop, String item_numid) throws SQLException {
		update_conn = getConnection();
		update_sql = "update item_detail set " + kind + " = ? where Item_numID = ?";
		update_ps = update_conn.prepareStatement(update_sql);
		update_ps.setString(1, prop);
		update_ps.setString(2, item_numid);
		update_ps.executeUpdate();
		free(null, update_ps, update_conn);
	}
	
	private static void print(String Item_Prop, String item_numid) throws SQLException {
		String[] desc = Item_Prop.split(";");
		for (String string : desc) {
			if(string.startsWith("品牌")) {
				String[] prop = string.split("：");
				System.err.println("品牌:" + prop[1]);
				doUpdate("brand", prop[1], item_numid);
			}
			if(string.startsWith("风格")) {
				String[] prop = string.split("：");
				System.err.println("风格:" + prop[1]);
				doUpdate("fashion", prop[1], item_numid);
			}
		}
	}
	
	private static void getCategory(String Pro_Category, String Sub_Category, String item_numid) throws SQLException {
		int start = Pro_Category.indexOf("/",Pro_Category.indexOf(Sub_Category)) + 1;
		int end_maybe = Pro_Category.indexOf("/", start);
		int end = (end_maybe==-1)?Pro_Category.length():end_maybe;
//		System.err.println(start);
//		System.err.println(end);
		String catag = Pro_Category.substring(start, end);
		doUpdate("catag", catag, item_numid);
	}

	private static void update() throws SQLException {
		conn = getConnection();
		select_sql = "select item_numid,item_prop,sub_category,category from item_detail limit 10;";
		ps = conn.prepareStatement(select_sql);
		rs = ps.executeQuery();
		while(rs.next()) {
			String item_prop = rs.getString("item_Prop");
			String sub_category = rs.getString("Sub_Category");
			String item_numid = rs.getString("item_numid");
			String category = rs.getString("category");
			print(item_prop, item_numid);
			getCategory(sub_category, category, item_numid);
		}
		free(rs, ps, conn);
	}

	public static void main(String[] args) throws SQLException {
		Date date1 = new Date();
		update();
		Date date2 = new Date();
		System.err.println(date2.getTime() - date1.getTime() + "ms");
	}
}