mybatisplus代码生成器使用（java代码生成工具）

前言：

原本想使用autogenerator 是 mybatis-plus 的官方代码生成器 ，尝试了一下，竟然报错，原因可能是mybatis-plus和mybatis-plus-generator 的版本不一致，因为我用的mybatis-plus 的版本是3.42 ，但是mybatis-plus-generator的3.4.2不知道怎么了，下载不下来，只能下载3.4.1，发现运行起来老是报错，还有一堆配置说明要看，于是自己手写生成代码的工具类，觉得更简单些。分享给大家，请多多指教。

pom文件引入java-mysql 驱动依赖

<dependency>

<groupid>mysql</groupid>

<artifactid>mysql-connector-java</artifactid>

<version>8.0.22</version>

</dependency>

单类代码实现，复制粘贴到编辑器里，主方法运行即可。

import org.apache.commons.lang3.stringutils;

import java.io.file;

import java.io.fileoutputstream;

import java.sql.connection;

import java.sql.databasemetadata;

import java.sql.drivermanager;

import java.sql.resultset;

import java.text.simpledateformat;

import java.util.date;

/**

* mybatis plus通用生成工具

* 可生成业务接口、mapper接口、实体类

*

* @author tarzan liu

* @date 2021/4/10 19:44

*/

public class mybatisplustools {

private static final string driver = “com.mysql.cj.jdbc.driver”;//驱动

private static final string user = “root”; //数据库账号

private static final string pwd = “123456”; //数据库密码

private static final string url = “
jdbc:mysql://127.0.0.1:3306/ofcms” + “?user=” + user + “&password=” + pwd+”&useunicode=true&characterencoding=utf-8&zerodatetimebehavior=converttonull”; //链接参数

private static string tablename = “of_cms_ad”; // 数据库表名

private static string aliasname = “cms_ad”; // 数据库别名,可以与数据库表名相同

private static final string packagepath = “com/tarzan/cms”; //mapper.xml命名空间路径

private static final string packagename = “com.tarzan.cms”; //mapper.xml命名空间路径

private static final string author = “tarzan”; // 作者

private static final string rootpathname = “src/main/java/”; // 默认生成主文件夹路径

private static connection getconnection = null;

static simpledateformat format = new simpledateformat(“yyyy-mm-dd hh:mm:ss”);

/**

* 链接数据库

*/

private static connection getconnections() {

try {

class.forname(driver);

getconnection = drivermanager.getconnection(url);

} catch (exception e) {

e.printstacktrace();

}

return getconnection;

}

/**

* 格式化默认值

*/

private static string defaultvalue(string value) {

if (stringutils.isnotblank(value)) {

return “；默认值：” + value;

}

{

return “”;

}

}

private static string getaliasname(string tablename,string prefix){

return tablename.substring(prefix.length());

}

/**

* 格式化数据类型

* 返回的是基本类型的包装类

* 如果使用基本数据类型long

*/

private static string formattype(string typevalue) {

if (“bit”.equalsignorecase(typevalue)) {

return “boolean”;

}

else if (

typevalue.equalsignorecase(“int”) || typevalue.equalsignorecase(“int unsigned”)

|| typevalue.equalsignorecase(“tinyint”) || typevalue.equalsignorecase(“tinyint unsigned”)

|| typevalue.equalsignorecase(“smallint”) || typevalue.equalsignorecase(“smallint unsigned”)

|| typevalue.equalsignorecase(“mediumint”) || typevalue.equalsignorecase(“mediumint unsigned”)

) {

return “integer”;

} else if (typevalue.equalsignorecase(“bigint”) || typevalue.equalsignorecase(“bigint unsigned”)) {

return “long”;

} else if (typevalue.equalsignorecase(“float”) || typevalue.equalsignorecase(“float unsigned”)) {

return “float”;

} else if (typevalue.equalsignorecase(“decimal”) || typevalue.equalsignorecase(“decimal unsigned”) || typevalue.equalsignorecase(“numeric”) || typevalue.equalsignorecase(“numeric unsigned”)

|| typevalue.equalsignorecase(“real”) || typevalue.equalsignorecase(“real unsigned”) || typevalue.equalsignorecase(“money”) || typevalue.equalsignorecase(“money unsigned”)

|| typevalue.equalsignorecase(“smallmoney”) || typevalue.equalsignorecase(“smallmoney unsigned”)) {

return “double”;

} else if (typevalue.equalsignorecase(“varchar”) || typevalue.equalsignorecase(“char”)

|| typevalue.equalsignorecase(“nvarchar”) || typevalue.equalsignorecase(“nchar”)

|| typevalue.equalsignorecase(“text”)) {

return “string”;

} else if (typevalue.equalsignorecase(“datetime”)) {

return “date”;

} else if (typevalue.equalsignorecase(“image”)) {

return “blod”;

} else {

return “long”;

}

}

/**

* 驼峰转换

*/

private static string columntoproperty(string column) {

stringbuilder result = new stringbuilder();

// 快速检查

if (column == null || column.isempty()) {

// 没必要转换

return “”;}

else column =column.tolowercase();

if (!column.contains(“_”)) {

// 不含下划线，仅将首字母小写

return column.substring(0, 1).tolowercase() + column.substring(1);

} else {

// 用下划线将原始字符串分割

string[] columns = column.split(“_”);

for (string columnsplit : columns) {

// 跳过原始字符串中开头、结尾的下换线或双重下划线

if (columnsplit.isempty()) {

continue;

}

// 处理真正的驼峰片段

if (result.length() == 0) {

// 第一个驼峰片段，全部字母都小写

result.append(columnsplit.tolowercase());

} else {

// 其他的驼峰片段，首字母大写

result.append(columnsplit.substring(0, 1).touppercase()).append(columnsplit.substring(1).tolowercase());

}

}

return result.tostring();

}

}

/**

* 实体名称转换

*/

private static string formatbeanname(string column) {

stringbuilder result = new stringbuilder();

// 快速检查

if (column == null || column.isempty()) {

// 没必要转换

return “”;

} else if (!column.contains(“_”)) {

// 不含下划线，仅将首字母大写

return column.substring(0, 1).touppercase() + column.substring(1);

} else {

// 用下划线将原始字符串分割

string[] columns = column.split(“_”);

for (string columnsplit : columns) {

// 跳过原始字符串中开头、结尾的下换线或双重下划线

if (columnsplit.isempty()) {

continue;

}

// 处理真正的驼峰片段

result.append(columnsplit.substring(0, 1).touppercase()).append(columnsplit.substring(1).tolowercase());

}

return result.tostring();

}

}

/**

* 实体类字段

*/

private static void getbean(string tablename,string aliasname) {

getconnection = getconnections();

stringbuilder sb = new stringbuilder();

try {

databasemetadata dbmd = getconnection.getmetadata();

resultset rs = dbmd.getcolumns(null, “%”, tablename, “%”);

string beanname = formatbeanname(aliasname);

sb.append(“package “+packagename+”.entity;\n\n”);

sb.append(“import com.baomidou.mybatisplus.annotation.tablename;\n”);

sb.append(“import lombok.data;\n”);

int length=sb.length();

boolean dateflag=false;

sb.append( ” /**\n” +

” * @author ” + author + “\n” +

” * @date “+ format.format(new date())+”\n” +

” */\n” +

“@data\n” +

“@tablename(\””+tablename+”\”)\n” +

“public class “+beanname+”entity {\n”);

while (rs.next()) {

if(formattype(rs.getstring(“type_name”)).equals(“date”)){

dateflag=true;

}

sb.append(“\t//”).append(rs.getstring(“remarks”)).append(defaultvalue(rs.getstring(“column_def”))).append(“\n”);

sb.append(“\tprivate “).append(formattype(rs.getstring(“type_name”))).append(” “).append(columntoproperty(rs.getstring(“column_name”))).append(“;\n”);

}

sb.append(“} “);

if(dateflag){

sb.insert(length, “import java.util.date;\n”);

}

} catch (exception e) {

e.printstacktrace();

}

write(sb.tostring(),”entity.java”,”entity”);

system.err.println(“\n类型：java数据层实体类（bean.java）” + “\n状态：成功” + “\n时间：” + format.format(new date()) + “\n”);

}

/**

* 生成dao层接口

*/

private static void getmapper(string tablename,string aliasname) {

stringbuilder sb = new stringbuilder();

try {

string beanname = formatbeanname(aliasname);

sb.append(“package “+packagename+”.mapper;\n\n”);

sb.append(“import com.baomidou.mybatisplus.core.mapper.basemapper;\n”);

sb.append(“import “+packagename+”.entity.”+beanname+”entity;\n”);

sb.append( “/**\n” +

” * @author ” + author + “\n” +

” * @date “+ format.format(new date())+”\n” +

” */\n” +

“public interface “+beanname+”mapper extends basemapper<“+beanname+”entity>{\n” +

” \n” +

“}”);

} catch (exception e) {

e.printstacktrace();

}

write(sb.tostring(),”mapper.java”,”mapper”);

system.err.println(“\n类型：java数据持久层接口（dao.java）” + “\n状态：成功” + “\n时间：” + format.format(new date()) + “\n”);

}

/**

* 生成service层接口

*/

private static void getservice(string tablename,string aliasname) {

stringbuilder sb = new stringbuilder();

try {

string beanname = formatbeanname(aliasname);

sb.append(“package “+packagename+”.service;\n\n”);

sb.append(“import com.baomidou.mybatisplus.extension.service.impl.serviceimpl;\n”);

sb.append(“import org.springframework.stereotype.service;\n”);

sb.append(“import “+packagename+”.mapper.”+beanname+”mapper;\n”);

sb.append(“import “+packagename+”.entity.”+beanname+”entity;\n”);

sb.append( “/**\n” +

” * @author ” + author + “\n” +

” * @date “+ format.format(new date())+”\n” +

” */\n” +

“@service\n” +

“public class “+beanname+”service extends serviceimpl<“+beanname+”mapper, “+beanname+”entity>{\n” +

“\n” +

“}”);

} catch (exception e) {

e.printstacktrace();

}

write(sb.tostring(),”service.java”,”service”);

system.err.println(“\n类型：java业务层接口（service.java）” + “\n状态：成功” + “\n时间：” + format.format(new date()) + “\n”);

}

/**

* 写文件，支持中文字符，在linux redhad下测试过

* @param str 文本内容

* @param name 文本名称

* */

private static void write(string str, string name,string type) {

try {

file dir = new file(rootpathname +packagepath+ “/” + type);

dir.mkdirs();

string path = dir.getpath() + “/” + formatbeanname(aliasname)+name;

file file = new file(path);

if (!file.exists())

file.createnewfile();

fileoutputstream out = new fileoutputstream(file, false); //如果追加方式用true

stringbuilder sb = new stringbuilder();

sb.append(str + “\n”);

out.write(sb.tostring().getbytes(“utf-8”));//注意需要转换对应的字符集

out.close();

} catch (exception e) {

e.printstacktrace();

}

}

//一次生产所有表

private static void tablenames() {

getconnection = getconnections();

try {

databasemetadata dbmd = getconnection.getmetadata();

resultset rs = dbmd.gettables(getconnection.getcatalog(), null, null, new string[] { “table” });

while (rs.next()) {

tablename=rs.getstring(“table_name”);

aliasname=getaliasname(tablename,”of_”);

//实体

getbean(tablename,aliasname);

//dao层接口

getmapper(tablename,aliasname);

//业务类接口

getservice(tablename,aliasname);

}

} catch (exception e) {

e.printstacktrace();

}

}

public static void main(string[] args) {

// tablenames();

//实体

getbean(tablename,aliasname);

//mapper接口

getmapper(tablename,aliasname);

//业务类接口

getservice(tablename,aliasname);

}

}

生成文件截图

实体

mapper

service