将mysql8.0下指定schema下的表导出为execl文件

记录一下，下次需要的时候就可以直接使用啦，方便写数据库结构，么么哒

注：其它版本的mysql数据库直接修改驱动类即可

mysql8.0驱动下载地址https://www.cnblogs.com/anovana/articles/8342021.html

import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.FileOutputStream;
import java.sql.Connection;

/**
 * 将数据库表导出为execl文件
 */
public class TableExeclUtil {
	static {
		try {
			Class.forName("com.mysql.cj.jdbc.Driver");
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
	}

	private static String tables = "select table_name,table_comment from information_schema.tables where table_schema = ?";

	private static String tableColumn = "select column_name,column_default,case is_nullable when 'NO' then '可为空' else '必须' end IS_NULLABLE,column_type,column_comment "
			+ "from information_schema.columns where table_schema = ? and table_name = ?";

	public static void main(String[] args) throws Exception {
		List p = new ArrayList<>();
		p.add("需要导出的schema名字");
		List> res = execSql(tables, p);
		// 创建Excel文件对象
		XSSFWorkbook wb = new XSSFWorkbook();
		createExcelTop(wb, "目录", new String[] { "序号", "表名", "表说明" }, new String[] {"TABLE_NAME", "TABLE_COMMENT"}, res);
		for(int i=0;i onetable = res.get(i);
			p = new ArrayList<>();
			p.add("cimb_batch");
			p.add(onetable.get("TABLE_NAME"));
			List> onetablecolumn = execSql(tableColumn, p);
			// for(int j=0;j> execSql(String sql, List params) {
		List> list = new ArrayList<>();
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = DriverManager.getConnection("连接地址", "用户名", "密码");
			ps = conn.prepareStatement(sql);
			for (int i = 0; i < params.size(); i++) {
				ps.setString(i+1, params.get(i));
			}
			rs = ps.executeQuery();
			ResultSetMetaData md = rs.getMetaData(); // 获得结果集结构信息,元数据
			int columnCount = md.getColumnCount(); // 获得列数
			while (rs.next()) {
				Map rowData = new HashMap<>();
				for (int i = 1; i <= columnCount; i++) {
					rowData.put(md.getColumnName(i), rs.getString(i));
				}
				list.add(rowData);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				if (rs != null)
					rs.close();
				if (ps != null)
					ps.close();
				if (conn != null)
					conn.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		return list;
	}

	/**
	 * 创建excel的表头,设置字体及字体颜色，设置单元格填充色
	 * 
	 * @param hssfWorkbook
	 * @param tableHead
	 * @param data
	 * @throws Exception
	 */
	public static void createExcelTop(XSSFWorkbook xf, String sheetName, String[] tableHead, String[] datacolumn, List> data) throws Exception {
		// 创建sheet对象
		Sheet sheet = xf.createSheet(sheetName);
		// 创建row
		Row row = sheet.createRow(1);

		//关键点 IndexedColors.AQUA.getIndex() 对应颜色
		CellStyle style = xf.createCellStyle();
		style.setFillForegroundColor(IndexedColors.GREY_25_PERCENT.getIndex());
		style.setFillPattern(CellStyle.SOLID_FOREGROUND);
		// 创建cell
		for(int i=0;i onedata = data.get(i-1);
			for(int j=0;j