导出数据库表以及备注为excel

import com.alibaba.excel.annotation.ExcelProperty;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class FieldData{
    //表名
    @ExcelProperty(value = "表名", index = 0)
    private String tableName;
    //表字段
    @ExcelProperty(value = "表字段", index = 1)
    private String field;
    //表字段类型
    @ExcelProperty(value = "表字段类型", index = 2)
    private String fieldType;
    //表字段备注
    @ExcelProperty(value = "表字段备注", index = 3)
    private String fieldCommit;
}

import com.alibaba.excel.annotation.ExcelProperty;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class TableData {
    //表名
    @ExcelProperty(value = "表名", index = 0)
    private String tableName;
    //表备注
    @ExcelProperty(value = "表备注", index = 1)
    private String remark;
}

import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.write.metadata.WriteSheet;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Test{
    private final static String fileName = "D:\\MyDocuments\\wangyong77\\桌面\\topTable3.xlsx";
    private final static String driver = "com.mysql.cj.jdbc.Driver";
    private final static String ip = "10.130.201.237:";
    private final static String user = "tkbus";
    private final static String password = "tkbus123";
    private final static String mydata = "tkbus";

    private static Connection conn;

    public static void main(String[] args) {
        DBinit ();
        getTableInfo ();
        DBclose ();
    }

    public static void getTableInfo() {
        try {
            //获取数据库的元数据
            DatabaseMetaData dbMetaData = conn.getMetaData ();
            System.out.println ("---------------获取" + conn.getCatalog () + "库的所有表名----------------");
            //从元数据中获取到所有的表名
            ResultSet rs = dbMetaData.getTables (conn.getCatalog (),null,null,new String[]{"TABLE"});
            //存放所有表名
            List<String> tableNames = new ArrayList<> ();
            //存放当前表的字段
            List<String> fields = new ArrayList<> ();
            //存放当前表的字段类型
            List<String> fieldstype = new ArrayList<> ();
            //存放当前表的字段属性
            List<String> commits = new ArrayList<> ();
            List<TableData> tableList = new ArrayList ();
            Map<Integer,List<FieldData>> map = new HashMap<> ();
            TableData table;
            while (rs.next ()) {
//                System.out.println("表名: "+rs.getString("TABLE_NAME"));
//                System.out.println("表类型: "+rs.getString("TABLE_TYPE"));
//                System.out.println("表所属数据库: "+rs.getString("TABLE_CAT"));
//                System.out.println("表所属用户名: "+rs.getString("TABLE_SCHEM"));
//                System.out.println("表备注: "+rs.getString("REMARKS"));
                if (rs.getString ("TABLE_NAME").contains ("copy") || HasDigit (rs.getString ("TABLE_NAME"))) {
                    continue;
                }
                tableNames.add (rs.getString ("TABLE_NAME"));
                table = new TableData ();
                table.setTableName (rs.getString ("TABLE_NAME"));
                table.setRemark (rs.getString ("REMARKS"));
                tableList.add (table);
            }
            //查询每个表的字段
            for (int i = 0;i < tableNames.size ();i++) {
                List<FieldData> filedlist = new ArrayList ();
                if (tableNames.get (i).contains ("copy") || HasDigit (tableNames.get (i))) {
                    continue;
                }
                String sql = "select * from " + tableNames.get (i);
                System.out.println ("表开始" + tableNames.get (i));
                PreparedStatement ps = conn.prepareStatement (sql);
                ResultSet rstable = ps.executeQuery ();
                //结果集元数据
                ResultSetMetaData meta = rstable.getMetaData ();
                //表列数量
                int columeCount = meta.getColumnCount ();
                FieldData data;
                for (int k = 1;k <= columeCount;k++) {
                    data = new FieldData ();
                    data.setTableName (tableNames.get (i));
                    data.setField (meta.getColumnName (k));
                    data.setFieldType (meta.getColumnTypeName (k));
                    filedlist.add (data);
                    fields.add (meta.getColumnName (k));
                    fieldstype.add (meta.getColumnTypeName (k));
                }
//                System.out.println("表"+tableNames.get(i)+"字段: "+fields);
//                System.out.println("表"+tableNames.get(i)+"字段类型: "+fieldstype);
                fields.clear ();
                ResultSet rs1 = rs = ps.executeQuery ("show full columns from " + tableNames.get (i));
                while (rs1.next ()) {
                    commits.add (rs.getString ("Comment"));
                }
//                System.out.println("表"+tableNames.get(i)+"字段备注类型: "+commits);
                for (int j = 0;j < filedlist.size ();j++) {
                    filedlist.get (j).setFieldCommit (commits.get (j));
                }
                map.put (i,filedlist);
                commits.clear ();
                System.out.println ("表完成" + tableNames.get (i));
            }
//            createTableExcel(tableList);
            createExcel (map);
        } catch (Exception e) {
            e.printStackTrace ();
        }
    }

    public static void DBinit() {
        //驱动程序名
        Properties props = new Properties ();
        props.put ("user",user);
        props.put ("password",password);
        props.put ("useInformationSchema","true"); //表注释
        //不同端口号
        String[] db_url_port = {"3306"};
        //数据库服务器
        String dbServer;
        for (String db_port : db_url_port) {
            dbServer = ip + db_port;
            //URL指向要访问的数据库名mydata
            String url = "jdbc:mysql://" + dbServer + "/" + mydata;
            try {
                Class.forName (driver);
                //声明Connection对象
                conn = DriverManager.getConnection (url,props);
                if (!conn.isClosed ()) {
                    System.out.println ("当前访问数据库端口号为" + db_port + "，数据库连接成功！");
                    break;
                }
            } catch (Exception e) {
                System.out.println ("当前访问数据库端口号为" + db_port + "，数据库连接失败！");
                continue;
            }
        }
    }

    public static void DBclose() {
        try {
            conn.close ();
        } catch (SQLException e) {
            System.out.println ("数据关闭异常");
            e.printStackTrace ();
        }
    }

    /**
     * 生成表内容详细信息
     * @param map
     */
    public static void createExcel(Map<Integer,List<FieldData>> map) {
        System.out.println ("开始写入excel");
        ExcelWriter excelWriter = EasyExcel.write (fileName).build ();
        WriteSheet writeSheet;
        //map根据key排序
        for (Map.Entry<Integer,List<FieldData>> map1 : map.entrySet ()) {
//            EasyExcel.write(fileName, FieldData.class).sheet(map1.getKey()).doWrite(map1.getValue());
            // 每次都要创建writeSheet 这里注意必须指定sheetNo。这里注意DemoData.class 可以每次都变，我这里为了方便 所以用的同一个class 实际上可以一直变
            writeSheet = EasyExcel.writerSheet (map1.getKey (),map1.getValue ().get (0).getTableName ()).head (FieldData.class).build ();
            // 分页去数据库查询数据 这里可以去数据库查询每一页的数据
            excelWriter.write (map1.getValue (),writeSheet);
        }
        excelWriter.finish ();
        System.out.println ("excel生成完毕");
    }

    /**
     * 生成表信息
     * @param tableList
     */
    public static void createTableExcel(List<TableData> tableList) {
        System.out.println ("开始写入Tableexcel");
        EasyExcel.write (fileName,TableData.class).sheet ("top表").doWrite (tableList);
        System.out.println ("Tableexcel生成完毕");
    }

    public static boolean HasDigit(String content) {
        boolean flag = false;
        Pattern p = Pattern.compile (".*\\d+.*");
        Matcher m = p.matcher (content);
        if (m.matches ()) {
            flag = true;
        }
        return flag;
    }

}

import com.alibaba.excel.annotation.ExcelProperty;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class FieldData{
//表名
@ExcelProperty(value = "表名", index = 0)
private String tableName;
//表字段
@ExcelProperty(value = "表字段", index = 1)
private String field;
//表字段类型
@ExcelProperty(value = "表字段类型", index = 2)
private String fieldType;
//表字段备注
@ExcelProperty(value = "表字段备注", index = 3)
private String fieldCommit;
}