我这边是用的maven引入mysql驱动,上一波依赖
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.19</version>
</dependency>
亲测可用，但是其中生成几张表对应的实体，有些表的字段类型没写进去的需要自己补充，要不要生成get，set方法可以自己看着改改
package com.springdemo.getEntityFromMysql;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MySQLGeneratorEntityUtil {
//表名
private String tableName;
//列名数组
private String[] colNames;
//列名类型数组
private String[] colTypes;
//列名大小数组
private int[] colSizes;
//列名注释
private Map colNamesComment = new HashMap();
//是否需要导入包java.util.*
private boolean needUtil = false;
//是否需要导入包java.sql.*
private boolean needSql = false;
//是否需要导入包java.math.BigDecimal
private boolean needBigDecimal = false;
//是否创建EntityHelper
private boolean needEntityHelper = true;
private static final SimpleDateFormat SDF = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
private static final String SQL = "SELECT * FROM ";// 数据库操作
// 数据库配置信息
private static final String URL = "jdbc:mysql://xxx.xxx.xxx.xxx:3306/xxx";
private static final String NAME = "xxx";
private static final String PASS = "xxx";
private static final String DRIVER = "com.mysql.jdbc.Driver";
//指定实体生成所在包的路径
private static String basePath = new File("").getAbsolutePath();
//指定包名
private static String packageOutPath = "com.springdemo.getEntityFromMysql";
//作者名字
private String authorName = "FelixChan";
//指定需要生成的表的表名，全部生成设置为null
private String[] generateTables = {
"xxx"};
//主键
private static String pk;
private MySQLGeneratorEntityUtil() {
}
/**
* @description 生成class的所有内容
*/
private String parse() {
StringBuffer sb = new StringBuffer();
sb.append("package " + packageOutPath + ";\r\n");
sb.append("\r\n");
// 判断是否导入工具包
if (needUtil) {
sb.append("import java.util.Date;\r\n");
sb.append("import java.time.*;\r\n");
}
if (needSql) {
sb.append("import java.sql.*;\r\n");
}
for (int i = 0; i < colNames.length; i++) {
String hasbd = sqlType2JavaType(colTypes[i]);
if(hasbd =="BigDecimal" || "BigDecimal".equals(hasbd)) {
needBigDecimal=true;}
}
if(needBigDecimal) {
sb.append("import java.math.BigDecimal;\r\n");
}
// 注释部分
sb.append("/**\r\n");
sb.append(" * table name: " + tableName + "\r\n");
sb.append(" * author name: " + authorName + "\r\n");
sb.append(" * create time: " + SDF.format(new Date()) + "\r\n");
sb.append(" */ \r\n");
// 实体部分
String classExtends = "";
if(needEntityHelper) {
classExtends=" extends EntityHelper";
}
sb.append("public class " + under2camel(tableName, true) + classExtends + "{\r\n\r\n");
processAllAttrs(sb);// 属性
sb.append("\r\n");
processConstructor(sb);//构造函数
processAllMethod(sb);// get set方法
processToString(sb);
if(needEntityHelper) {
processEntityHelper(sb,pk);
}
sb.append("}\r\n");
return sb.toString();
}
/**
* @param sb
* @description 生成所有成员变量及注释
* @author paul
* @version V1.0
*/
private void processAllAttrs(StringBuffer sb) {
for (int i = 0; i < colNames.length; i++) {
if(colNamesComment.get(colNames[i])!=null &&!"".equals(colNamesComment.get(colNames[i]))) {
sb.append("\t/*"+colNamesComment.get(colNames[i])+"*/\r\n");
}
sb.append("\tprivate " + sqlType2JavaType(colTypes[i]) + " " + colNames[i] + ";\r\n");
}
}
/**
* EntityHelper
* @param sb
* @param pk
*/
private void processEntityHelper(StringBuffer sb,String pk) {
sb.append("\t@Override\r\n");
sb.append("\tpublic String getPrimaryKey() {\r\n");
sb.append("\t\treturn \""+pk+"\";\r\n");
sb.append("\t}\r\n");
}
/**
* 重写toString()方法
* @param sb
*/
private void processToString(StringBuffer sb) {
sb.append("\t@Override\r\n\tpublic String toString() {\r\n");
sb.append("\t\treturn \"" +tableName + "[\" + \r\n");
for (int i = 0; i < colNames.length; i++) {
if (i != 0)
sb.append("\t\t\t\", ");
if (i == 0)
sb.append("\t\t\t\"");
sb.append(colNames[i] + "=\" + "
+ colNames[i]).append(" + \r\n");
if (i == colNames.length - 1) {
sb.append("\t\t\t\"]\";\r\n");
}
}
sb.append("\t}\r\n");
}
/**
* 构造函数
* @param sb
*/
private void processConstructor(StringBuffer sb) {
StringBuffer p = new StringBuffer();
StringBuffer v = new StringBuffer();
for(int i = 0; i < colNames.length; i++) {
p.append(sqlType2JavaType(colTypes[i])+" "+colNames[i]);
if(i!=colNames.length-1) {
p.append(",");
}
v.append("\t\tthis."+colNames[i]+"="+colNames[i]+";\r\n");
}
//无参数构造函数
sb.append("\tpublic "+under2camel(tableName,true)+"() {\r\n");
sb.append("\t\tsuper();\r\n");
sb.append("\t}\r\n");
//带参构造函数
sb.append("\tpublic "+under2camel(tableName,true)+"("+p.toString()+") {\r\n");
sb.append(v.toString());
sb.append("\t}\r\n");
}
/**
* @param sb
* @description 生成所有get/set方法
*/
private void processAllMethod(StringBuffer sb) {
for (int i = 0; i < colNames.length; i++) {
sb.append("\tpublic void set" + initCap(colNames[i]) + "(" + sqlType2JavaType(colTypes[i]) + " "
+ colNames[i] + "){\r\n");
sb.append("\t\tthis." + colNames[i] + "=" + colNames[i] + ";\r\n");
sb.append("\t}\r\n");
sb.append("\tpublic " + sqlType2JavaType(colTypes[i]) + " get" + initCap(colNames[i]) + "(){\r\n");
sb.append("\t\treturn " + colNames[i] + ";\r\n");
sb.append("\t}\r\n");
}
}
/**
* @param str 传入字符串
* @return
* @description 将传入字符串的首字母转成大写
*/
private String initCap(String str) {
char[] ch = str.toCharArray();
if (ch[0] >= 'a' && ch[0] <= 'z')
ch[0] = (char) (ch[0] - 32);
return new String(ch);
}
/**
* 功能：下划线命名转驼峰命名
* @param s
* @param fistCharToUpperCase 首字母是否大写
* @author 呐喊
* @return
*/
private String under2camel(String s,boolean fistCharToUpperCase) {
String separator = "_";
String under="";
s = s.toLowerCase().replace(separator, " ");
String sarr[]=s.split(" ");
for(int i=0;i<sarr.length;i++)
{
String w=sarr[i].substring(0,1).toUpperCase()+sarr[i].substring(1);
under +=w;
}
if(!fistCharToUpperCase) {
under = under.substring(0,1).toLowerCase()+under.substring(1);
}
return under;
}
/**
* @return
* @description 查找sql字段类型所对应的Java类型
*/
private String sqlType2JavaType(String sqlType) {
if (sqlType.equalsIgnoreCase("bit")) {
return "boolean";
} else if (sqlType.equalsIgnoreCase("tinyint")) {
return "byte";
} else if (sqlType.equalsIgnoreCase("smallint")) {
return "short";
} else if (sqlType.equalsIgnoreCase("int")) {
return "int";
} else if (sqlType.equalsIgnoreCase("bigint")) {
return "long";
} else if (sqlType.equalsIgnoreCase("float")) {
return "float";
} else if (sqlType.equalsIgnoreCase("numeric")
|| sqlType.equalsIgnoreCase("real") || sqlType.equalsIgnoreCase("money")
|| sqlType.equalsIgnoreCase("smallmoney")) {
return "double";
} else if (sqlType.equalsIgnoreCase("varchar") || sqlType.equalsIgnoreCase("char")
|| sqlType.equalsIgnoreCase("nvarchar") || sqlType.equalsIgnoreCase("nchar")
|| sqlType.equalsIgnoreCase("text")|| sqlType.equalsIgnoreCase("longtext")) {
return "String";
} else if (sqlType.equalsIgnoreCase("datetime") || sqlType.equalsIgnoreCase("timestamp")) {
return "LocalDateTime";
}else if (sqlType.equalsIgnoreCase("date")) {
return "LocalDate";
} else if (sqlType.equalsIgnoreCase("image")) {
return "Blod";
}else if (sqlType.equalsIgnoreCase("decimal")) {
return "BigDecimal";
}
return null;
}
/**
* 功能：获取并创建实体所在的路径目录
* @return
*/
private static String pkgDirName() {
String dirName = basePath + "/src/" + packageOutPath.replace(".", "/");
File dir = new File(dirName);
if (!dir.exists()) {
dir.mkdirs();System.out.println("mkdirs dir 【" + dirName + "】");}
return dirName;
}
/**
* 生成EntityHelper
*/
private void EntityHelper() {
String dirName = MySQLGeneratorEntityUtil.pkgDirName();
String javaPath = dirName + "/EntityHelper.java";
try {
StringBuffer sb = new StringBuffer();
sb.append("package " + packageOutPath + ";\r\n");
sb.append("\r\n");
sb.append("public abstract class EntityHelper{\r\n\r\n");
sb.append("\tpublic abstract String getPrimaryKey();\r\n");
sb.append("\r\n");
sb.append("}\r\n");
FileWriter fw = new FileWriter(javaPath);
PrintWriter pw = new PrintWriter(fw);
pw.println(sb.toString());
pw.flush();
if (pw != null){
pw.close();}
System.out.println("create class 【EntityHelper】");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* @description 生成方法
*/
private void generate() throws Exception {
//与数据库的连接
Connection con;
PreparedStatement pStemt = null;
Class.forName(DRIVER);
con = DriverManager.getConnection(URL, NAME, PASS);
System.out.println("connect database success..."+con);
//获取数据库的元数据
DatabaseMetaData db = con.getMetaData();
//是否有指定生成表，有指定则直接用指定表，没有则全表生成
List<String> tableNames = new ArrayList<>();
if (generateTables == null) {
//从元数据中获取到所有的表名
ResultSet rs = db.getTables(null, null, null, new String[] {
"TABLE" });
while (rs.next()) tableNames.add(rs.getString(3));
} else {
for (String tableName : generateTables) tableNames.add(tableName);
}
if(needEntityHelper) {
EntityHelper();
}
String tableSql;
PrintWriter pw = null;
for (int j = 0; j < tableNames.size(); j++) {
tableName = tableNames.get(j);
tableSql = SQL + tableName;
pStemt = con.prepareStatement(tableSql);
ResultSetMetaData rsmd = pStemt.getMetaData();
ResultSet rsk = con.getMetaData().getPrimaryKeys(con.getCatalog().toLowerCase(), null, tableName);
if (rsk.next()) {
String primaryKey = rsk.getString("COLUMN_NAME");
pk=primaryKey;
}
int size = rsmd.getColumnCount();
colNames = new String[size];
colTypes = new String[size];
colSizes = new int[size];
//获取所需的信息
for (int i = 0; i < size; i++) {
colNames[i] = rsmd.getColumnName(i + 1);
colTypes[i] = rsmd.getColumnTypeName(i + 1);
if (colTypes[i].equalsIgnoreCase("datetime"))
needUtil = true;
if (colTypes[i].equalsIgnoreCase("image") || colTypes[i].equalsIgnoreCase("text"))
needSql = true;
colSizes[i] = rsmd.getColumnDisplaySize(i + 1);
}
//获取字段注释
ResultSet rsComment = pStemt.executeQuery("show full columns from " + tableName);
while (rsComment.next()) {
colNamesComment.put(rsComment.getString("Field"), rsComment.getString("Comment"));
}
//解析生成实体java文件的所有内容
String content = parse();
//输出生成文件
String dirName = MySQLGeneratorEntityUtil.pkgDirName();
String javaPath = dirName + "/" + under2camel(tableName, true) + ".java";
FileWriter fw = new FileWriter(javaPath);
pw = new PrintWriter(fw);
pw.println(content);
pw.flush();
System.out.println("create class 【" + tableName + "】");
}
if (pw != null)
pw.close();
}
public static void main(String[] args) {
MySQLGeneratorEntityUtil instance = new MySQLGeneratorEntityUtil();
//instance.basePath=""; //指定生成的位置,默认是当前工程
try {
instance.generate();
System.out.println("generate Entity to classes successful!");
} catch (Exception e) {
e.printStackTrace();
}
}
}