网上下载的项目，有些只有代码，没有对应的数据库和sql语句。

需要自行根据Entity类来生成建表语句：

package com.xx;

import java.io.File;

import java.io.FileOutputStream;

import java.lang.reflect.Field;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

/**

* 根据 java 类自动生成sql 语句 - mysql

*/

public class SqlGenerator {

public static MapjavaProperty2SqlColumnMap = new HashMap<>();

static {

javaProperty2SqlColumnMap.put("Integer", "int");

javaProperty2SqlColumnMap.put("Short", "tinyint(4)");

javaProperty2SqlColumnMap.put("Long", "bigint");

javaProperty2SqlColumnMap.put("BigDecimal", "decimal(19,2)");

javaProperty2SqlColumnMap.put("Double", "double precision not null");

javaProperty2SqlColumnMap.put("Float", "float");

javaProperty2SqlColumnMap.put("boolean", "bit(1)");

javaProperty2SqlColumnMap.put("Timestamp", "datetime");

javaProperty2SqlColumnMap.put("Date", "datetime");

javaProperty2SqlColumnMap.put("String", "varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL");

}

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:\\Documents\\IdeaProjects\\xxxxxxx\\src\\main\\java\\com\\xx\\modules\\cms\\entity";

//生成sql的文件夹

//String filePath = "D:\\Documents\\IdeaProjects\\xxxxxxx\\";

//项目中实体类的路径

String prefix = "com.xx.modules.cms.entity.";

String className = "";

StringBuffer sqls = new StringBuffer();

//获取包下的所有类名称

Listlist = getAllClasses(packageName);

for (String str : list) {

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

String sql = generateSql(className, "");

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

* @param className 全类名

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

*/

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

try {

Class> clz = Class.forName(className);

className = clz.getSimpleName();

Field[] fields = clz.getDeclaredFields();

String param = "";

String column = "";

StringBuilder sql = null;

sql = new StringBuilder(50);

if (tableName == null || ("").equals(tableName)) {

tableName = clz.getName();

tableName = tableName.substring(tableName.lastIndexOf(".") + 1);

}

sql.append("\n\n/*========= "+tableName+" ==========*/\n");

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

sql.append("CREATE TABLE `").append(tableName).append("` ( \n");

String keyField = "";

for (Field f : fields) {

column = f.getName();

if (("serialVersionUID").equals(column)) {

continue;

}

param = f.getType().getSimpleName();

//将大写字母转小写，并添加下划线

for (int i = 0; i < column.length(); i++) {

char c = column.charAt(i);

if (Character.isUpperCase(c) && i>0) {

column = column.replaceAll(

Character.toString(c), "_"+Character.toLowerCase(c));

}

}

sql.append("`"+ column +"`");

sql.append(" ").append(javaProperty2SqlColumnMap.get(param));

//默认第一个是主键

if ("".equals(keyField)) {

keyField = column;

}

sql.append(",\n");

}

sql.append("PRIMARY KEY (`"+keyField+"`) USING BTREE,");

sql.append("\nINDEX `"+keyField+"`(`"+keyField+"`) USING BTREE ) ");

sql.append("\nENGINE = INNODB DEFAULT CHARSET= utf8;");

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

* @param packageName

* @return

*/

public static ListgetAllClasses(String packageName){

ListclassList = new ArrayList();

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

* @param str

* @param path

*/

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

byte[] sourceByte = str.getBytes();

if(null != sourceByte){

try {

//文件路径(路径+文件名)

File file = new File(path);

//文件不存在则创建文件，先创建目录

if (!file.exists()) {

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

dir.mkdirs();

file.createNewFile();

}

//文件输出流用于将数据写入文件

FileOutputStream outStream = new FileOutputStream(file);

outStream.write(sourceByte);

outStream.flush();

outStream.close();

System.out.println("生成成功");

} catch (Exception e) {

e.printStackTrace();

}

}

}

}