通过实体类生成建表SQL语句实现方法

   
   
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