Excel tool for generating database table structure

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One 、 design sketch

Single table

The database table structure is as follows

perform main After the method

Generated excel file

Multiple tables

Support the structure of all tables in the database , Generate excel

Two 、 How to use

pom file

		<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.17</version>
        </dependency>

        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.17</version>
        </dependency>

Tool class

package com.mabo.database;

import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.mabo.controller.TableInfo;
import com.mabo.excel.ExcelUtil;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;

public class DatabaseUtils {
    

    public static void main(String[] args) throws Exception {
    

        String driver = "com.mysql.cj.jdbc.Driver";
        String url = "jdbc:mysql://localhost:3306/xxx?serverTimezone=GMT";
        String user = "root";
        String password = "xxx";
		// Generated excel File storage path 
        String filePath="G:/";
		// All tables of the database are generated excel
// createDataBaseExcels(driver, url, user, password,filePath);

		// Database  file_info  Table to generate  excel
        createDataBaseExcel(driver, url, user, password,"file_info",filePath);
    }

    public static void createDataBaseExcels(String driver, String url, String user, String password,String filePath) throws Exception {
    
        JSONArray array = getTablesInfo(driver, url, user, password);
        String[] strArray = {
     " name ", " type ", " length ", " Required " ," notes "," remarks "};
        createDataBaseExcels(array,strArray,filePath);
    }

    public static void createDataBaseExcel(String driver, String url, String user, String password,String tableName,String filePath) throws Exception {
    
        String[] strArray = {
     " name ", " type ", " length ", " Required " ," notes "," remarks "};
        JSONArray jsonArray = getTableInfo(driver, url, user, password, tableName);
        String fileName=filePath+tableName+".xls";
        createDataBaseExcel(jsonArray, strArray,fileName);
        System.out.println(tableName+" Table generation succeeded , File path : "+fileName);
    }

    /** * @Description :  Generate all tables of the database excel * @Author : mabo */
    public static void createDataBaseExcels(JSONArray jsonArray, String[] strArray,String filePath) throws IOException {
    
        for (int i = 0; i < jsonArray.size(); i++) {
    
            JSONObject jsonObject = jsonArray.getJSONObject(i);
            String table = jsonObject.getString("table");
            JSONArray fields = jsonObject.getJSONArray("fields");
            String fileName=filePath+table+".xls";
            createDataBaseExcel(fields, strArray,fileName);
            System.out.println(table+" Table generation succeeded , File path : "+fileName);
        }
    }

    /** * @Description :  take fileName Table structure output to excel * @Author : mabo */

    public static void createDataBaseExcel(JSONArray jsonArray, String[] strArray, String fileName) throws IOException {
    
        //  Create a webbook, Corresponding to one Excel file 
        HSSFWorkbook wb = new HSSFWorkbook();
        //  stay webbook Add a sheet, Corresponding Excel In the document sheet
        HSSFSheet sheet = wb.createSheet("sheet1");
        //  stay sheet Add table header No 0 That's ok , Pay attention to the old version poi Yes Excel There is a limit to the number of rows and columns short
        HSSFRow row = sheet.createRow(0);
        //  Add title line 
        HSSFCell cell = null;
        for (int i = 0; i < strArray.length; i++) {
    
            //  Get the corresponding cells in the row 
            cell = row.createCell(i);
            //  Cell assignment 
            cell.setCellValue(strArray[i]);
        }

        //  Write entity data , In practical application, these data are obtained from the database ,list The order of strings in must be the same as array strArray In the same order 
        int i = 0;
        for (int j = 0; j < jsonArray.size(); j++) {
    
            JSONObject json=jsonArray.getJSONObject(j);
            i++;
            row = sheet.createRow(i );
            String name = json.getString("name");
            String type = json.getString("type").toLowerCase();
            Integer size = json.getInteger("size");
            String isNeed=" yes ";
            if (json.getBoolean("isNull").equals(true)){
    
                isNeed=" no ";
            }
            String remarks = json.getString("remarks");
            //  Add data row 

            for (int z = 0; z < strArray.length; z++) {
    
                cell = row.createCell(z);
                //  Get the corresponding cells in the row 
                //  Cell assignment 
                if (z==0){
    
                    cell.setCellValue(name);
                }
                else if (z==1){
    
                    cell.setCellValue(type);
                }
                else if (z==2){
    
                    cell.setCellValue(size);
                }
                else if (z==3){
    
                    cell.setCellValue(isNeed);
                }
                else if (z==4){
    
                    cell.setCellValue(remarks);
                }
            }
        }
// //  Step six , Save the file to the specified location 
        FileOutputStream fout = new FileOutputStream(fileName);
        try {
    
            wb.write(fout);
            fout.close();
        } catch (Exception e) {
    
            e.printStackTrace();
        }
        finally {
    
            fout.close();
        }
    }

    /** *  Read database  *  All table structures  */
    public static JSONArray getTablesInfo(String driver, String url, String user, String password) throws Exception {
    
        JSONArray array = new JSONArray();
        Class.forName(driver);
        Connection connection = DriverManager.getConnection(url, user, password);
        DatabaseMetaData metaData = connection.getMetaData();
// Get all the table names from the metadata 
        String[] types = {
    "TABLE"};
        //mysql-connector-java 6.0 Use this method below 
        //rs = db.getTables(null, null, null, new String[] { "TABLE" });

        //mysql-connector-java 6.x In this way 
        ResultSet tableResultSet = metaData.getTables(connection.getCatalog(), connection.getCatalog(), "%", types);

        while (tableResultSet.next()) {
    
            JSONObject json = new JSONObject();
            String tableName = tableResultSet.getString("TABLE_NAME");
            json.put("table",tableName);
            //  Get the table field structure 
            ResultSet columnResultSet = metaData.getColumns(null, "%", tableName, "%");
            JSONArray fields = new JSONArray();
            while (columnResultSet.next()) {
    
                JSONObject field = new JSONObject();
                //  Field name 
                String columnName = columnResultSet.getString("COLUMN_NAME");
                boolean repeat=false;
                // Cycle to see if the current value repeats 
                for (int i = 0; i < fields.size(); i++) {
    
                    JSONObject jsonObject = fields.getJSONObject(i);
                    String column_name = jsonObject.getString("name");
                    if (columnName.equals(column_name)){
    
                        repeat=true;
                        break;
                    }
                }
                if (repeat){
    
                    continue;
                }
                field.put("name",columnName);
                //  data type 
                String columnType = columnResultSet.getString("TYPE_NAME");
                field.put("type",columnType);
                //  Field length 
                int datasize = columnResultSet.getInt("COLUMN_SIZE");
                field.put("size",datasize);
                //  Number of decimal places 
                int digits = columnResultSet.getInt("DECIMAL_DIGITS");
                field.put("digits",digits);
                //  Can it be empty  1 Representative can be null  0 Representative cannot be empty 
                int nullable = columnResultSet.getInt("NULLABLE");
                if (nullable==1){
    
                    field.put("isNull",true);
                }
                else {
    
                    field.put("isNull",false);
                }
                //  describe 
                String remarks = columnResultSet.getString("REMARKS");
                field.put("remarks",remarks);
                fields.add(field);
            }
            json.put("fields",fields);
            array.add(json);
        }
        return array;
    }

    /** *  Read database  * tableName Table structure  */
    public static JSONArray getTableInfo(String driver, String url, String user, String password,String tableName) throws Exception {
    
        Class.forName(driver);
        Connection connection = DriverManager.getConnection(url, user, password);
        DatabaseMetaData metaData = connection.getMetaData();
        // Get all the table names from the metadata 
        String[] types = {
    "TABLE"};
        //mysql-connector-java 6.0 Use this method below 
        //rs = db.getTables(null, null, null, new String[] { "TABLE" });
        //mysql-connector-java 6.x In this way 
        ResultSet tableResultSet = metaData.getTables(connection.getCatalog(), connection.getCatalog(), "%", types);
        while (tableResultSet.next()) {
    
            JSONObject json = new JSONObject();
            String table = tableResultSet.getString("TABLE_NAME");
            if (table.equals(tableName)){
    
                ResultSet columnResultSet = metaData.getColumns(null, "%", tableName, "%");
                JSONArray fields = new JSONArray();
                while (columnResultSet.next()) {
    
                    JSONObject field = new JSONObject();
                    //  Field name 
                    String columnName = columnResultSet.getString("COLUMN_NAME");
                    boolean repeat=false;
                    // Cycle to see if the current value repeats 
                    for (int i = 0; i < fields.size(); i++) {
    
                        JSONObject jsonObject = fields.getJSONObject(i);
                        String column_name = jsonObject.getString("name");
                        if (columnName.equals(column_name)){
    
                            repeat=true;
                            break;
                        }
                    }
                    if (repeat){
    
                        continue;
                    }
                    field.put("name",columnName);
                    //  data type 
                    String columnType = columnResultSet.getString("TYPE_NAME");
                    field.put("type",columnType);
                    //  Field length 
                    int datasize = columnResultSet.getInt("COLUMN_SIZE");
                    field.put("size",datasize);
                    //  Number of decimal places 
                    int digits = columnResultSet.getInt("DECIMAL_DIGITS");
                    field.put("digits",digits);
                    //  Can it be empty  1 Representative can be null  0 Representative cannot be empty 
                    int nullable = columnResultSet.getInt("NULLABLE");
                    if (nullable==1){
    
                        field.put("isNull",true);
                    }
                    else {
    
                        field.put("isNull",false);
                    }
                    //  describe 
                    String remarks = columnResultSet.getString("REMARKS");
                    field.put("remarks",remarks);

                    fields.add(field);
                }
                return fields;
            }
        }
        return null;
    }
}