Java实现一键生成表controller,service,mapper文件
作者：zyqok
这篇文章主要为大家详细介绍了如何利用Java语言实现一键生成表controller,service,mapper文件，文中的示例代码讲解详细，需要的可以收藏一下
controller、service、Mapper文件的作用
Controller：控制器
业务模块流程的控制，不同的业务流程有不同的控制器
负责请求转发，接收页面过来的参数，传给service处理，接到返回值，并再次传给页面
- 控制处理前端请求和响应，与前端进行交互，给前端提供接口
- 调用Service层（定义的接口）
- 如果只是简单增删可以调用Mapper（不推荐）
Service：服务
相对独立，负责业务逻辑（功能）的设计，是一个接口类
Mapper:（DAO）
访问数据库，对数据库进行操作，提供接口给Service层
- 当sql语句发生变化更改时，我们可以只修改对应的XML文件，而无需再修改Mapper，这样每次更改sql语句时，代码就可以不用再次重新编译！
- 直接与数据库打交道(执行SQL语句)，接口提供给service层
下图为java约定俗成的几个文件的作用
实现代码
package com.unisoc.isupport.utils;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.text.SimpleDateFormat;
import java.util.*;
/**
* @author Yuanqiang.Zhang
* @since 2023/5/15
*/
public class GeneratorTool {
/**
* 数据库连接信息
*/
private static String IP = "172.0.0.1";
private static int PORT = 3306;
private static String DATABASE_NAME = "zyq_test";
private static String USERNAME = "root";
private static String PASSWORD = "root";
/**
* 创建者
*/
private static String AUTHOR = "YuanQiang.Zhang";
/**
* 基础包路径
*/
private static String BASE_PACKAGE = "com.zdb";
/**
* 需要生成的表
*/
private static String[] TABLE_NAMES = {"z_word"};
/**
* 忽略的前缀
*/
private static String[] IGNORE_PREFIX = {"z_"};
/**
* 主方法运行
*
* @param args args
*/
public static void main(String[] args) {
Connection conn = getConnection();
for (String tableName : TABLE_NAMES) {
createTableFiles(conn, tableName);
}
}
private static String getWithoutPrefixTableName(String tableName) {
if (IGNORE_PREFIX.length == 0) {
return tableName;
}
for (String s : IGNORE_PREFIX) {
if (tableName.startsWith(s)) {
return tableName.substring(s.length());
}
}
return tableName;
}
public static void createTableFiles(Connection conn, String tableName) {
List<String[]> fields = getTableFields(conn, tableName);
String withoutPrefixTableName = getWithoutPrefixTableName(tableName);
String className = getClassName(withoutPrefixTableName);
createEntity(fields, tableName, className, withoutPrefixTableName);
// createMapper(withoutPrefixTableName, className);
// createMapperXml(withoutPrefixTableName, className);
// createService(withoutPrefixTableName, className);
// createServiceImpl(withoutPrefixTableName, className);
// createController(withoutPrefixTableName, className);
}
public static void createController(String tableName, String className) {
StringBuilder sb = new StringBuilder();
sb.append(String.format("package %s.controller;\n\n", BASE_PACKAGE));
sb.append(String.format("import %s.service.%sService;\n", BASE_PACKAGE, className));
sb.append("import lombok.extern.slf4j.Slf4j;\n");
sb.append("import org.springframework.web.bind.annotation.RequestMapping;\n");
sb.append("import org.springframework.web.bind.annotation.RestController;\n");
sb.append("import org.springframework.beans.factory.annotation.Autowired;\n\n");
sb.append("/**\n");
sb.append(String.format(" * @author %s\n", AUTHOR));
sb.append(String.format(" * @since %s\n", formatDateTime(new Date())));
sb.append(" */\n");
sb.append("@RestController\n");
sb.append("@Slf4j\n");
String path = String.valueOf(className.toCharArray()[0]).toLowerCase() + className.substring(1);
sb.append(String.format("@RequestMapping(\"/%s\")\n", path));
sb.append(String.format("public class %sController {\n\n", className));
sb.append(" @Autowired\n");
sb.append(String.format(" private %sService service;\n\n", className));
sb.append("}\n");
String fileName = className + "Controller.java";
String filePath = getBasePath() + "/controller/" + fileName;
File file = new File(filePath);
if (file.exists()) {
System.out.println(tableName + " 的 Controller 类已经存在，不再生成。");
} else {
writeFileContent(file, sb.toString());
System.out.println(tableName + " 的 Controller 类生成完毕。");
}
}
public static void createServiceImpl(String tableName, String className) {
StringBuilder sb = new StringBuilder();
sb.append(String.format("package %s.service.impl;\n\n", BASE_PACKAGE));
sb.append("import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;\n");
sb.append(String.format("import %s.entity.%s;\n", BASE_PACKAGE, className));
sb.append(String.format("import %s.mapper.%sMapper;\n", BASE_PACKAGE, className));
sb.append(String.format("import %s.service.%sService;\n", BASE_PACKAGE, className));
sb.append("import lombok.extern.slf4j.Slf4j;\n");
sb.append("import org.springframework.beans.factory.annotation.Autowired;\n");
sb.append("import org.springframework.stereotype.Service;\n\n");
sb.append("/**\n");
sb.append(String.format(" * @author %s\n", AUTHOR));
sb.append(String.format(" * @since %s\n", formatDateTime(new Date())));
sb.append(" */\n");
sb.append("@Slf4j\n");
sb.append("@Service\n");
sb.append(String.format("public class %sServiceImpl extends ServiceImpl<%sMapper, %s> implements %sService { \n\n", className, className, className, className));
sb.append(" @Autowired\n");
sb.append(String.format(" private %sMapper mapper;\n\n", className));
sb.append("}\n");
String fileName = className + "ServiceImpl.java";
String filePath = getBasePath() + "/service/impl/" + fileName;
File file = new File(filePath);
if (file.exists()) {
System.out.println(tableName + " 的 ServiceImpl 已经存在，不再生成。");
} else {
writeFileContent(file, sb.toString());
System.out.println(tableName + " 的 ServiceImpl 生成完毕。");
}
}
public static void createService(String tableName, String className) {
StringBuilder sb = new StringBuilder();
sb.append(String.format("package %s.service;\n\n", BASE_PACKAGE));
sb.append("import com.baomidou.mybatisplus.extension.service.IService;\n");
sb.append(String.format("import %s.entity.%s;\n\n", BASE_PACKAGE, className));
sb.append("/**\n");
sb.append(String.format(" * @author %s\n", AUTHOR));
sb.append(String.format(" * @since %s\n", formatDateTime(new Date())));
sb.append(" */\n");
sb.append(String.format("public interface %sService extends IService<%s> {\n\n", className, className));
sb.append("}\n");
String fileName = className + "Service.java";
String filePath = getBasePath() + "/service/" + fileName;
File file = new File(filePath);
if (file.exists()) {
System.out.println(tableName + " 的 Service 类已经存在，不再生成。");
} else {
writeFileContent(file, sb.toString());
System.out.println(tableName + " 的 Service 类生成完毕。");
}
}
public static void createMapperXml(String tableName, String className) {
StringBuilder sb = new StringBuilder();
sb.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
sb.append("<!DOCTYPE mapper PUBLIC \"-//mybatis.org//DTD Mapper 3.0//EN\" \"http://mybatis.org/dtd/mybatis-3-mapper.dtd\">\n");
sb.append(String.format("<mapper namespace=\"%s.mapper.%sMapper\">\n\n", BASE_PACKAGE, className));
sb.append("</mapper>\n");
String fileName = className + "Mapper.xml";
String filePath = "src/main/resources/mapper/" + fileName;
File file = new File(filePath);
if (file.exists()) {
System.out.println(tableName + " 的 Mapper.xml 已经存在，不再生成。");
} else {
writeFileContent(file, sb.toString());
System.out.println(tableName + " 的 Mapper.xml 生成完毕。");
}
}
public static void createMapper(String tableName, String className) {
StringBuilder sb = new StringBuilder();
sb.append(String.format("package %s.mapper;\n\n", BASE_PACKAGE));
sb.append(String.format("import %s.entity.%s;\n", BASE_PACKAGE, className));
sb.append("import com.baomidou.mybatisplus.core.mapper.BaseMapper;\n\n");
sb.append("/**\n");
sb.append(String.format(" * @author %s\n", AUTHOR));
sb.append(String.format(" * @since %s\n", formatDateTime(new Date())));
sb.append(" */\n");
sb.append(String.format("public interface %sMapper extends BaseMapper<%s> {\n\n", className, className));
sb.append("}\n");
String fileName = className + "Mapper.java";
String filePath = getBasePath() + "/mapper/" + fileName;
File file = new File(filePath);
if (file.exists()) {
System.out.println(tableName + " 的 Mapper 类已经存在，不再生成。");
} else {
writeFileContent(file, sb.toString());
System.out.println(tableName + " 的 Mapper 类生成完毕。");
}
}
public static void createEntity(List<String[]> fields, String tableName, String className, String withoutPrefixTableName) {
StringBuilder sb = new StringBuilder();
sb.append(String.format("package %s.entity;\n\n", BASE_PACKAGE));
sb.append("import com.baomidou.mybatisplus.annotation.*;\n");
sb.append("import lombok.Data;\n\n");
// 判断是否有 timestamp 类型
if (hasDate(fields)) {
sb.append("import java.util.Date;\n\n");
}
sb.append("/**\n");
sb.append(" * @author " + AUTHOR + "\n");
sb.append(" * @since " + formatDateTime(new Date()) + "\n");
sb.append(" */\n");
sb.append("@Data\n");
sb.append(String.format("@TableName(\"%s\")\n", tableName));
sb.append(String.format("public class %s {\n\n", className));
for (String[] attrs : fields) {
String columnName = attrs[0];
String dataType = attrs[1];
String columnComment = attrs[2];
String columnKey = attrs[3];
if ("PRI".equals(columnKey)) {
sb.append(" /** 主键 */\n");
sb.append(String.format(" @TableId(value = \"%s\", type = IdType.AUTO)\n", columnName));
} else {
if (Objects.nonNull(columnComment) && !columnComment.isEmpty()) {
sb.append(String.format(" /** %s */\n", columnComment));
}
sb.append(String.format(" @TableField(value = \"%s\")\n", columnName));
}
String fieldName = getFieldName(columnName);
if (dataType.endsWith("int")) {
if ("bigint".equals(dataType)) {
sb.append(String.format(" private Long %s;\n", fieldName));
} else {
sb.append(String.format(" private Integer %s;\n", fieldName));
}
} else if (dataType.endsWith("char") || dataType.endsWith("text")) {
sb.append(String.format(" private String %s;\n", fieldName));
} else if ("timestamp".equals(dataType) || "datetime".equals(dataType)) {
sb.append(String.format(" private Date %s;\n", fieldName));
} else if ("double".equals(dataType)) {
sb.append(String.format(" private Double %s;\n", fieldName));
} else {
System.err.println("发现没有判断到的数据类型：" + dataType);
}
sb.append("\n");
}
sb.append("\n}");
String fileName = className + ".java";
String filePath = getBasePath() + "/entity/" + fileName;
File file = new File(filePath);
if (file.exists()) {
System.out.println(withoutPrefixTableName + " 的 Entity 类已经存在，不再生成。");
} else {
writeFileContent(file, sb.toString());
System.out.println(withoutPrefixTableName + " 的 Entity 类生成完毕。");
}
}
private static String getBasePath() {
return "src/main/java/" + BASE_PACKAGE.replace(".", "/");
}
private static String getFieldName(String columnName) {
if (!columnName.contains("_")) {
StringBuilder sb = new StringBuilder();
char[] chars = columnName.toCharArray();
sb.append(String.valueOf(chars[0]).toLowerCase());
if (chars.length <= 1) {
return sb.toString();
} else {
for (int i = 1; i < chars.length; i++) {
sb.append(chars[i]);
}
}
return sb.toString();
}
String s = getClassName(columnName);
return String.valueOf(s.toCharArray()[0]).toLowerCase() + s.substring(1);
}
private static boolean hasDate(List<String[]> fields) {
if (Objects.isNull(fields) || fields.isEmpty()) {
return false;
}
for (String[] attrs : fields) {
String dataType = attrs[1];
if ("timestamp".equals(dataType) || "datetime".equals(dataType)) {
return true;
}
}
return false;
}
private static List<String[]> getTableFields(Connection conn, String tableName) {
String sql = "SELECT * FROM information_schema.columns WHERE table_schema = '" + DATABASE_NAME + "' AND table_name = '" + tableName + "'";
List<String[]> fields = new ArrayList<>();
try {
Statement stat = conn.createStatement();
ResultSet rs = stat.executeQuery(sql);
while (rs.next()) {
String columnName = rs.getString("COLUMN_NAME");
String dataType = rs.getString("DATA_TYPE");
String columnComment = rs.getString("COLUMN_COMMENT");
String columnKey = rs.getString("COLUMN_KEY");
String[] attrs = new String[4];
attrs[0] = columnName;
attrs[1] = dataType;
attrs[2] = columnComment;
attrs[3] = columnKey;
fields.add(attrs);
}
} catch (Exception e) {
e.printStackTrace();
}
return fields;
}
/**
* 获取类名
*
* @param tableName 表名
* @return 类名
*/
private static String getClassName(String tableName) {
char[] chars = tableName.toCharArray();
boolean flag = true;
StringBuilder sb = new StringBuilder();
for (char c : chars) {
if (c == '_') {
flag = true;
continue;
}
if (flag) {
sb.append(String.valueOf(c).toUpperCase());
} else {
sb.append(String.valueOf(c).toLowerCase());
}
flag = false;
}
return sb.toString();
}
/**
* 获取数据库链接
*
* @return Connection
*/
private static Connection getConnection() {
try {
Class.forName("com.mysql.cj.jdbc.Driver");
String url = String.format("jdbc:mysql://%s:%s/%s", IP, PORT, DATABASE_NAME);
return DriverManager.getConnection(url, USERNAME, PASSWORD);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 将内容写入到文件中
*
* @param file 文件
* @param content 内容
*/
public static void writeFileContent(File file, String content) {
String parentPath = file.getParent();
if (Objects.nonNull(parentPath) && !parentPath.isEmpty()) {
File parent = new File(parentPath);
if (!parent.exists()) {
parent.mkdirs();
}
}
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}
try (FileWriter writer = new FileWriter(file)) {
writer.write(content);
writer.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
private static String formatDateTime(Date date) {
return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.CHINA).format(date);
}
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