import java.io.File;







import java.io.FileOutputStream;







import java.lang.reflect.Field;







import java.util.ArrayList;







import java.util.List;















import org.hibernate.hql.internal.ast.SqlGenerator;







import org.slf4j.Logger;







import org.slf4j.LoggerFactory;







public class Test {







    private static final Logger logger = LoggerFactory.getLogger(SqlGenerator.class);















    public static void main(String[] args) {







        //实体类所在的package在磁盘上的绝对路径







        String packageName = "d:/workspace/";







        //生成sql的文件夹







        String filePath = "I:/create/";







        //项目中实体类的路径







        String prefix = "com.zh.entity.";







        String className = "";















        StringBuffer sqls = new StringBuffer();







        //获取包下的所有类名称







        List<String> list = getAllClasses(packageName);







        for (String str : list) {







            className = prefix + str.substring(0, str.lastIndexOf("."));







            String sql = generateSql(className, filePath);







            sqls.append(sql);







        }







        System.out.println(sqls.toString());







        StringToSql(sqls.toString(), filePath + "report.sql");















    }







    /**







     * 根据实体类生成建表语句







     * @author







     * @date	2019年1月14日







     * @param className 全类名







     * @param filePath 磁盘路径  如 : d:/workspace/







     */







    public static String generateSql(String className,String filePath){







        try {







            Class<?> clz = Class.forName(className);







            className = clz.getSimpleName();







            Field[] fields = clz.getDeclaredFields();







            StringBuffer column = new StringBuffer();







            String varchar = " varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,";







            for (Field f : fields) {







                column.append(" \n `"+f.getName()+"`").append(varchar);







            }







            StringBuffer sql = new StringBuffer();







            sql.append("\n DROP TABLE IF EXISTS `"+className+"`; ")







                    .append(" \n CREATE TABLE `"+className+"`  (")







                    .append(" \n `id` int(11) NOT NULL AUTO_INCREMENT,")







                    .append(" \n "+column)







                    .append(" \n PRIMARY KEY (`id`) USING BTREE,")







                    .append("\n INDEX `id`(`id`) USING BTREE")







                    .append(" \n ) ENGINE = InnoDB AUTO_INCREMENT = 1 CHARACTER SET = utf8 COLLATE = utf8_general_ci;");







            return sql.toString();







        } catch (ClassNotFoundException e) {







            logger.debug("该类未找到！");







            return null;







        }















    }















    /**







     * 获取包下的所有类名称,获取的结果类似于 XXX.java







     * @author







     * @date	2019年1月14日







     * @param packageName







     * @return







     */







    public static List<String> getAllClasses(String packageName){







        List<String> classList = new ArrayList<String>();







        String className="";







        File f = new File(packageName);







        if(f.exists() && f.isDirectory()){







            File[] files = f.listFiles();







            for (File file : files) {







                className = file.getName();







                classList.add(className);







            }







            return classList;







        }else{







            logger.debug("包路径未找到！");







            return null;







        }







    }







    /**







     * 将string 写入sql文件







     * @author







     * @date	2019年1月14日







     * @param str







     * @param path







     */







    public static void StringToSql(String str,String path){







        byte[] sourceByte = str.getBytes();







        if(null != sourceByte){







            try {







                File file = new File(path);     //文件路径（路径+文件名）







                if (!file.exists()) {   //文件不存在则创建文件，先创建目录







                    File dir = new File(file.getParent());







                    dir.mkdirs();







                    file.createNewFile();







                }







                FileOutputStream outStream = new FileOutputStream(file);    //文件输出流用于将数据写入文件







                outStream.write(sourceByte);







                outStream.flush();







                outStream.close();  //关闭文件输出流







                System.out.println("生成成功");







            } catch (Exception e) {







                e.printStackTrace();







            }







        }







    }







}

生成的代码截图如下：

原文地址：https://blog.csdn.net/zgsdzczh/article/details/86487149