之前两篇介绍了使用Hibernate生成SQL全量脚本文件的方式,若需要生成增量脚本进行版本维护呢?想到的对于生成增量脚本的方案可归为:
经过实际查询,第一种方案实现基本为零,暂未找到相关实现;第二种方案可以通过Hibernate的SchemaUpdate实现,也可以通过Liquibase实现;第三种方案可以通过Liquibase实现。
本次介绍通过Hibernate的SchemaUpdate生成SQL增脚本文件的方式,与SchemaExport生成全量脚本一样也可以通过两种方式生成。不同之处在于生成全量脚本时可以不配置数据库连接信息,,但生成增量脚本时必须配置数据库连接信息,从而连接数据库,不然只有程序中的注解,缺少参照的从而无法生成增量。
目录
这个和之前的SchemaExport一样,只是createData方法换成了updatData方法。之前说可能会产生报错提示的情况,当精确到类似路径时classpath*:**/**/entity/*.class
(即所有含注解的class均在entity包中)即可避免。这里不再细谈,具体的注释可见之前的文章。
package com.windcoder.qycms.core.basis.test.Hibernate.ddl;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.boot.spi.MetadataImplementor;
import org.hibernate.dialect.Dialect;
import org.hibernate.dialect.MySQL5InnoDBDialect;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.hibernate.tool.hbm2ddl.SchemaUpdate;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.core.type.classreading.SimpleMetadataReaderFactory;
import org.springframework.util.FileCopyUtils;
import org.springframework.util.StreamUtils;
import org.springframework.util.StringUtils;
import javax.persistence.Entity;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.lang.annotation.Annotation;
import java.nio.charset.Charset;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.stream.Collectors;
/**
* 可以使用JPA Entity类生成DDL查询的类
*
* 生成成功,但DIALECT_CLASS获取不友好。
* https://gist.github.com/sbcoba/e4264f4b4217746767e682c61f9dc3a6
*/
public class JpaEntityDdlExport {
/**
* 要创建的文件名
*/
private static final String SCHEMA_UPDATE_SQL = "schema-update_%s.sql";
/**
* 域类路径位置(如果范围很宽,则只能找到带有@Entity的类)
*/
private final static String PATTERN = "classpath*:**/**/entity/.class";
private final static String PATH = "com.windcoder";
/**
* DB类型生成DDL
* org.hibernate.dialect.* 包参考*
*
* - Oracle Oracle10gDialect.class
* - H2 H2Dialect.class
* ...
*
*/
private final static Class<? extends Dialect> DIALECT_CLASS = MySQL5InnoDBDialect.class;
public static void main(String[] args) {
updatData(args);
}
/**
* 生成全量SQL脚本
* @param args
*/
public static void updatData(String[] args){
File propsFile = new File("./qycms-core/common/src/main/resources/application.properties");
Properties properties = new Properties();
try {
properties.load(new FileInputStream(propsFile));
Map<String, Object> settings = new HashMap<>();
settings.put("hibernate.dialect", DIALECT_CLASS);
settings.put("hibernate.connection.driver", properties.getProperty("spring.datasource.driver-class-name"));
settings.put("hibernate.connection.url", properties.getProperty("spring.datasource.url"));
settings.put("hibernate.connection.username", properties.getProperty("spring.datasource.username"));
settings.put("hibernate.connection.password", properties.getProperty("spring.datasource.password"));
settings.put("hibernate.physical_naming_strategy","org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy");
settings.put("hibernate.implicit_naming_strategy","org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy");
settings.put("hibernate.id.new_generator_mappings", false);
StandardServiceRegistry standardServiceRegistry = new StandardServiceRegistryBuilder()
.applySettings(settings)
.build();
MetadataSources metadata = new MetadataSources(standardServiceRegistry);
String pattern = getPattern(args);
List<Class<?>> classes = getClassesByAnnotation(Entity.class, pattern);
classes.forEach(metadata::addAnnotatedClass);
MetadataImplementor metadataImplementor = (MetadataImplementor) metadata.getMetadataBuilder().build();
SchemaUpdate schemaUpdate = new SchemaUpdate(metadataImplementor);
schemaUpdate.setOutputFile(getOutputFilename(args));
schemaUpdate.setDelimiter(";");
schemaUpdate.setFormat(false);
schemaUpdate.execute(true, false);
} catch (IOException e) {
e.printStackTrace();
}
}
private static String getPattern(String[] args) {
String pattern = PATTERN;
if(args != null && args.length >= 3
&& StringUtils.hasText(args[2])) {
pattern = args[2];
}
return pattern;
}
private static void appendMetaData(String outputFile, Map<String, Object> settings) {
String charsetName = "UTF-8";
File ddlFile = new File(outputFile);
try {
StringBuilder sb = new StringBuilder();
sb.append("/* Generate Environment\n");
for (Map.Entry<String, Object> entry : settings.entrySet()) {
sb.append(entry.getKey().toString() + ": " + entry.getValue() + "\n");
}
sb.append("*/\n");
String ddlFileContents = StreamUtils.copyToString(new FileInputStream(ddlFile), Charset.forName(charsetName));
sb.append(ddlFileContents);
FileCopyUtils.copy(sb.toString().getBytes(charsetName), ddlFile);
} catch (IOException e) {
e.printStackTrace();
}
}
private static List<Class<?>> getClassesByAnnotation(Class<? extends Annotation> annotation, String pattern) {
return getResources(pattern).stream()
.map(r -> metadataReader(r))
.filter(Objects::nonNull)
.filter(mr -> mr.getAnnotationMetadata().hasAnnotation(annotation.getName()))
.map(mr -> entityClass(mr))
.filter(Objects::nonNull)
.collect(Collectors.toList());
}
/**
* 获取与模式对应的资源信息。
* @param pattern
* @return
*/
private static List<Resource> getResources(String pattern) {
PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
Resource[] resources;
try {
resources = resolver.getResources(pattern);
} catch (IOException e) {
throw new RuntimeException(e);
}
return Arrays.asList(resources);
}
private static Class<?> entityClass(MetadataReader mr) {
String className = mr.getClassMetadata().getClassName();
Class<?> clazz;
try {
clazz = Class.forName(className);
} catch (ClassNotFoundException e) {
System.err.printf("%s Class not found", className);
return null;
}
return clazz;
}
private static MetadataReader metadataReader(Resource r) {
MetadataReader mr;
try {
mr = new SimpleMetadataReaderFactory().getMetadataReader(r);
} catch (IOException e) {
System.err.printf(e.getMessage());
return null;
}
return mr;
}
private static String getOutputFilename(String[] args) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd_HHmmss");
String currentDate = sdf.format(Calendar.getInstance().getTime());
if(args != null && args.length > 0
&& StringUtils.hasText(args[0])) {
String customSchemaName = args[0];
if(customSchemaName.contains("%s")) {
return String.format(customSchemaName, currentDate);
}
return customSchemaName;
}
return String.format(SCHEMA_UPDATE_SQL, currentDate);
}
}
这个和之前创建全量脚本的类似,区别之处是全量脚本的StandardServiceRegistry是通过StandardServiceRegistryBuilder直接创建的,增量的是通过
LocalContainerEntityManagerFactoryBean->EntityManagerFactoryImpl(由getNativeEntityManagerFactory()强转得到)->
SessionFactoryImpl(由getSessionFactory()强转得到)->StandardServiceRegistry(由getSessionFactoryOptions().getServiceRegistry()得到)
完整文件如下:
package com.windcoder.qycms.core.basis.test.Hibernate.ddl;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.spi.MetadataImplementor;
import org.hibernate.internal.SessionFactoryImpl;
import org.hibernate.jpa.internal.EntityManagerFactoryImpl;
import org.hibernate.tool.hbm2ddl.SchemaUpdate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.stereotype.Component;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.List;
/**
* 参考资料:
* https://stackoverflow.com/questions/34612019/programmatic-schemaexport-schemaupdate-with-hibernate-5-and-spring-4
*/
@Component
public class JPASchemaSchemaUpdate implements ApplicationRunner {
private static final String SCHEMA_SQL2 = "db/base/update-ddl_2_%s.sql";
@Autowired
LocalContainerEntityManagerFactoryBean fb;
@Override
public void run(ApplicationArguments args) throws Exception {
EntityManagerFactoryImpl emf=(EntityManagerFactoryImpl)fb.getNativeEntityManagerFactory();
SessionFactoryImpl sf= (SessionFactoryImpl) emf.getSessionFactory();
StandardServiceRegistry serviceRegistry = sf.getSessionFactoryOptions().getServiceRegistry();
MetadataSources metadata = new MetadataSources(serviceRegistry);
List<String> managedClassNames = fb.getPersistenceUnitInfo().getManagedClassNames();
for (String managedClassName : managedClassNames) {
metadata.addAnnotatedClassName(managedClassName);
}
MetadataImplementor metadataImplementor = (MetadataImplementor) metadata.getMetadataBuilder().build();
SchemaUpdate schemaUpdate = new SchemaUpdate(metadataImplementor);
schemaUpdate.setOutputFile(getOutputFilename());
schemaUpdate.setDelimiter(";");
schemaUpdate.setFormat(false);
schemaUpdate.execute(true, false);
}
private static String getOutputFilename() {
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd_HHmmss");
String currentDate = sdf.format(Calendar.getInstance().getTime());
return String.format(SCHEMA_SQL2, currentDate);
}
}