根据mybatis-generator自动生成的mapper来逆向生成数据库sql文件

package com.etc.utils;

import com.etc.model.Tab;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.SAXReader;

import org.dom4j.Element;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

/**
 * @author ：cuibo
 * @date ：Created in 2019/3/31 12:33
 */
public class createsql {

        public static void main(String[] args) throws Exception {
            generateSql("D://projects", "D://arcfacedm.sql");
        }
        /**
         * 生成sql
         * @param dirPath mapper.xml的父级文件夹
         * @param sqlFile 选择你将要生成sql的文件
         * @throws IOException
         */
        private static void generateSql(String dirPath,String sqlFile) throws IOException {
            FileWriter fw = null;
            try {
                File dir = new File(dirPath);
                File sql = new File(sqlFile);
                if (sql.exists()){
                    sql.delete();
                }
                sql.createNewFile();
                fw = new FileWriter(sql);

                if (dir.exists() && dir.isDirectory()){
                    File[] files = dir.listFiles();
                    for (File file : files) {
                        if (file.isFile() && file.getName().endsWith(".xml")){
                            System.out.println(file.getName());
                            fw.append("\r\n");
                            fw.append(getSql(file));
                            fw.flush();
                        }
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            }finally{
                if (fw != null)
                    fw.close();
            }
        }

        private static String getSql(File xmlfile) throws DocumentException {
            SAXReader saxReader= new SAXReader();
            Document document = saxReader.read(xmlfile);
            org.dom4j.Element root = document.getRootElement();
            Element resultMap = root.element("resultMap");
            Tab tab = new Tab();
            tab.setTableName(getTableName(root));
            tab.setColumns(getColumns(resultMap));
            return tab.toString();
        }
        private static Map<String,String> getColumns(Element resultMap){
            List<Element> elements = resultMap.elements();
            Map<String,String> map = new LinkedHashMap<String, String>();
            for (Element element : elements) {
                map.put(element.attribute("column").getValue(), element.attribute("jdbcType").getValue());
            }
            return map;
        }
        private static String getTableName(Element root){
            Element selectByPrimaryKey = root.element("select");
            String selectStr = selectByPrimaryKey.getTextTrim();
            String tableName = selectStr.split("from")[1].trim().split(" ")[0].trim();
            return tableName;
        }
    }

package com.etc.model;

import java.util.Map;
import java.util.Set;

/**
 * @author ：cuibo
 * @date ：Created in 2019/3/31 12:38
 */
public class Tab {

    private String tableName;

    private String idName;

    private String idType;

    private Map<String,String> columns;

    public String getTableName() {
        return tableName;
    }
    public void setTableName(String tableName) {
        this.tableName = tableName;
    }
    public String getIdName() {
        return idName;
    }
    public void setIdName(String idName) {
        this.idName = idName;
    }
    public String getIdType() {
        return idType;
    }
    public void setIdType(String idType) {
        this.idType = idType;
    }
    public Map<String, String> getColumns() {
        return columns;
    }
    public void setColumns(Map<String, String> columns) {
        this.columns = columns;
    }
    @Override
    public String toString() {

        StringBuffer sb = new StringBuffer("DROP TABLE  IF EXISTS "+tableName+";");
        sb.append("\r\n");
        sb.append("CREATE TABLE ");
        sb.append(tableName);
        sb.append("(");
        sb.append("\r\n");
        Set<Map.Entry<String,String>> set = columns.entrySet();
        int size = set.size();
        int i = 0;
        for (Map.Entry<String,String> entry : set) {
            i++;
            sb.append("\t"+entry.getKey()+" "+format(entry.getValue()));
            if (size != i){
                sb.append(" ,");
                sb.append("\r\n");
            }

        }
        sb.append("\r\n");
        sb.append(");");
        sb.append("\r\n");
        return sb.toString();

    }
    private String format(String val){
        if (val.equals("VARCHAR")){
            return "VARCHAR(255)";
        }
        return val;
    }


}