From 1fe9433332a9ed00429c54cef2dbbd0a78f72ec1 Mon Sep 17 00:00:00 2001
From: lanyuanxiaoyao <lanyuanxiaoyao@gmail.com>
Date: Thu, 11 Sep 2025 10:21:21 +0800
Subject: [PATCH] =?UTF-8?q?feat:=20=E5=A2=9E=E5=8A=A0DDL=E8=AF=AD=E5=8F=A5?=
 =?UTF-8?q?=E7=94=9F=E6=88=90=E7=9A=84=E5=B0=8F=E5=B7=A5=E5=85=B7?=
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---
 pom.xml                                       |   7 ++
 .../service/template/util/DDLGenerator.java   | 116 ++++++++++++++++++
 2 files changed, 123 insertions(+)
 create mode 100644 src/main/java/com/lanyuanxiaoyao/service/template/util/DDLGenerator.java

diff --git a/pom.xml b/pom.xml
index 690b6a5..dc4cd5d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -43,6 +43,13 @@
             <version>${querydsl.version}</version>
         </dependency>
 
+        <dependency>
+            <groupId>org.hibernate.orm</groupId>
+            <artifactId>hibernate-ant</artifactId>
+            <version>6.6.15.Final</version>
+            <scope>provided</scope>
+        </dependency>
+
         <dependency>
             <groupId>org.mapstruct</groupId>
             <artifactId>mapstruct</artifactId>
diff --git a/src/main/java/com/lanyuanxiaoyao/service/template/util/DDLGenerator.java b/src/main/java/com/lanyuanxiaoyao/service/template/util/DDLGenerator.java
new file mode 100644
index 0000000..a430142
--- /dev/null
+++ b/src/main/java/com/lanyuanxiaoyao/service/template/util/DDLGenerator.java
@@ -0,0 +1,116 @@
+package com.lanyuanxiaoyao.service.template.util;
+
+import jakarta.persistence.Entity;
+import java.util.EnumSet;
+import java.util.List;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.model.naming.CamelCaseToUnderscoresNamingStrategy;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+import org.hibernate.tool.hbm2ddl.SchemaExport;
+import org.hibernate.tool.schema.TargetType;
+import org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy;
+import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
+import org.springframework.core.type.filter.AnnotationTypeFilter;
+import org.springframework.util.ClassUtils;
+
+/**
+ * 构造DDL建表语句
+ * <p>
+ * 该工具类用于生成数据库表结构的DDL语句，通过扫描指定包下的实体类，
+ * 利用Hibernate的SchemaExport工具生成建表SQL脚本。
+ * </p>
+ *
+ * <p>
+ * 使用示例：
+ * <pre>
+ * DDLGenerator.generateDDL(
+ *     List.of("com.example.entity", "com.another.package"),
+ *     "./sql",
+ *     MySQL8Dialect.class,
+ *     "jdbc:mysql://localhost:3306/test",
+ *     "username",
+ *     "password",
+ *     com.mysql.cj.jdbc.Driver.class
+ * );
+ * </pre>
+ * </p>
+ *
+ * @author lanyuanxiaoyao
+ */
+public class DDLGenerator {
+  public static void generateDDL(
+      List<String> entityPackages,
+      String ddlFilePath,
+      Class<?> dialect,
+      String jdbc,
+      String username,
+      String password,
+      Class<?> driver
+  ) {
+    var metadataSources = new MetadataSources(
+        new StandardServiceRegistryBuilder()
+            .applySetting("hibernate.dialect", dialect.getName())
+            .applySetting("hibernate.physical_naming_strategy", CamelCaseToUnderscoresNamingStrategy.class.getName())
+            .applySetting("hibernate.implicit_naming_strategy", SpringImplicitNamingStrategy.class.getName())
+            .applySetting("hibernate.connection.url", jdbc)
+            .applySetting("hibernate.connection.username", username)
+            .applySetting("hibernate.connection.password", password)
+            .applySetting("hibernate.connection.driver_class", driver.getName())
+            .build()
+    );
+
+    // 使用Spring类路径扫描方式查找所有@Entity注解的类
+    var scanner = new ClassPathScanningCandidateComponentProvider(false);
+    scanner.addIncludeFilter(new AnnotationTypeFilter(Entity.class));
+
+    // 遍历所有包路径，扫描@Entity注解的类
+    for (String entityPackage : entityPackages) {
+      var candidates = scanner.findCandidateComponents(entityPackage);
+
+      // 将找到的实体类添加到metadataSources中
+      for (var candidate : candidates) {
+        // 处理candidate或getBeanClassName可能为null的情况
+        if (candidate == null || candidate.getBeanClassName() == null) {
+          continue;
+        }
+
+        try {
+          var entityClass = ClassUtils.forName(candidate.getBeanClassName(), DDLGenerator.class.getClassLoader());
+          metadataSources.addAnnotatedClass(entityClass);
+        } catch (ClassNotFoundException e) {
+          throw new RuntimeException("Failed to load entity class: " + candidate.getBeanClassName(), e);
+        }
+      }
+    }
+
+    var export = new SchemaExport();
+    export.setFormat(true);
+    export.setDelimiter(";");
+    export.setOutputFile(ddlFilePath + "/" + dialect.getSimpleName() + ".sql");
+    export.setOverrideOutputFileContent();
+    export.execute(EnumSet.of(TargetType.SCRIPT), SchemaExport.Action.CREATE, metadataSources.buildMetadata());
+  }
+
+  /**
+   * 兼容旧版本的方法签名
+   *
+   * @param entityPackage 实体类包路径
+   * @param ddlFilePath   DDL文件输出路径
+   * @param dialect       方言类
+   * @param jdbc          JDBC连接URL
+   * @param username      数据库用户名
+   * @param password      数据库密码
+   * @param driver        JDBC驱动类
+   */
+  public static void generateDDL(
+      String entityPackage,
+      String ddlFilePath,
+      Class<?> dialect,
+      String jdbc,
+      String username,
+      String password,
+      Class<?> driver
+  ) {
+    generateDDL(List.of(entityPackage), ddlFilePath, dialect, jdbc, username, password, driver);
+  }
+}
\ No newline at end of file