Querydsl与JPA Criteria对比系列第6部分：Spring Boot 3.2升级指南——针对Spring Data JPA与Querydsl项目

教程
Hibernate

去年，我为Spring Boot 3.0.x的升级撰写了一篇文章，名为”Spring Boot 3.0升级指南：Spring Data JPA与Querydsl“。如今，Spring Boot已更新至3.2版本。让我们探讨在升级到Spring Boot 3.2.2时可能遇到的两个问题。

SAT项目所采用的技术包括：

  1. Spring Boot 3.2.2及Spring Framework 6.1.3
  2. Hibernate + JPA模型生成器6.4.1最终版
  3. Spring Data JPA 3.2.2
  4. Querydsl 5.0.0.

变更详情

Spring Boot 3.2的所有变更均记录于Spring Boot 3.2发布说明以及Spring Framework 6.1的6.1版本新特性中。

关于Spring Boot 3.2.2的最新变更，可在GitHub上查阅。

发现的问题

  • A different treatment of Hibernate dependencies due to the changed hibernate-jpamodelgen behavior for annotation processors
  • Unpaged类已重新设计。

首先从Hibernate依赖开始。

集成静态元模型生成

最大的变化来自hibernate-jpamodelgen依赖，它正在生成一个静态元模型。在Hibernate 6.3中，为了减轻传递性依赖，对依赖的处理方式进行了更改。Spring Boot 3.2.0将hibernate-jpamodelgen依赖提升到了6.3版本（参见依赖升级）。遗憾的是，新版本导致了编译错误（见下文）。

注意：此处使用的Spring Boot 3.2.2已经采用Hibernate 6.4，行为相同。

编译错误

随着这一变化，我们的项目（Maven构建）使用Spring Boot 3.2.2时因类似错误而编译失败：

Plain Text

  

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  3.049 s
[INFO] Finished at: 2024-01-05T08:43:10+01:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.11.0:compile (default-compile) on project sat-jpa: Compilation failure: Compilation failure: 
[ERROR]   on the class path. A future release of javac may disable annotation processing
[ERROR]   unless at least one processor is specified by name (-processor), or a search
[ERROR]   path is specified (--processor-path, --processor-module-path), or annotation
[ERROR]   processing is enabled explicitly (-proc:only, -proc:full).
[ERROR]   Use -Xlint:-options to suppress this message.
[ERROR]   Use -proc:none to disable annotation processing.
[ERROR] <SAT_PATH>\sat-jpa\src\main\java\com\github\aha\sat\jpa\city\CityRepository.java:[3,41] error: cannot find symbol
[ERROR]   symbol:   class City_
[ERROR]   location: package com.github.aha.sat.jpa.city
[ERROR] <SAT_PATH>\sat-jpa\src\main\java\com\github\aha\sat\jpa\city\CityRepository.java:[3] error: static import only from classes and interfaces
...
[ERROR] <SAT_PATH>\sat-jpa\src\main\java\com\github\aha\sat\jpa\country\CountryCustomRepositoryImpl.java:[4] error: static import only from classes and interfaces
[ERROR] java.lang.NoClassDefFoundError: net/bytebuddy/matcher/ElementMatcher
[ERROR] 	at org.hibernate.jpamodelgen.validation.ProcessorSessionFactory.<clinit>(ProcessorSessionFactory.java:69)
[ERROR] 	at org.hibernate.jpamodelgen.annotation.AnnotationMeta.handleNamedQuery(AnnotationMeta.java:104)
[ERROR] 	at org.hibernate.jpamodelgen.annotation.AnnotationMeta.handleNamedQueryRepeatableAnnotation(AnnotationMeta.java:78)
[ERROR] 	at org.hibernate.jpamodelgen.annotation.AnnotationMeta.checkNamedQueries(AnnotationMeta.java:57)
[ERROR] 	at org.hibernate.jpamodelgen.annotation.AnnotationMetaEntity.init(AnnotationMetaEntity.java:297)
[ERROR] 	at org.hibernate.jpamodelgen.annotation.AnnotationMetaEntity.create(AnnotationMetaEntity.java:135)
[ERROR] 	at org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor.handleRootElementAnnotationMirrors(JPAMetaModelEntityProcessor.java:360)
[ERROR] 	at org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor.processClasses(JPAMetaModelEntityProcessor.java:203)
[ERROR] 	at org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor.process(JPAMetaModelEntityProcessor.java:174)
[ERROR] 	at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:1021)
[ER...
[ERROR] 	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:348)
[ERROR] Caused by: java.lang.ClassNotFoundException: net.bytebuddy.matcher.ElementMatcher
[ERROR] 	at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:445)
[ERROR] 	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:593)
[ERROR] 	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526)
[ERROR] 	... 51 more
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

这是由于Hibernate迁移指南中宣布的静态元模型生成方法的改变所致（参见集成静态元模型生成及原始问题HHH-17362）。他们对此变更的解释如下：

“…在之前的Hibernate ORM版本中，你可能在不知不觉中将hibernate-jpamodelgen的依赖泄露到了编译类路径中。随着Hibernate ORM 6.3的发布，你现在可能会在注解处理过程中遇到与缺少Antlr类相关的编译错误。”

依赖变更

如截图所示，Hibernate的依赖确实发生了变化。

  • Spring Boot 3.1.6:

  • Spring Boot 3.2.2:

解释

根据迁移指南所述，我们需要将pom.xml从简单的Maven依赖更改为Maven编译器插件的注解处理器路径（参见文档）。

解决方案

我们应按照上一篇文章的建议，移除Maven依赖hibernate-jpamodelgen和querydsl-apt（以我们为例）。取而代之的是，pom.xml需要通过maven-compiler-plugin定义静态元模型生成器，如下所示：

XML

  

<plugins>
	<plugin>
		<groupId>org.apache.maven.plugins</groupId>
		<artifactId>maven-compiler-plugin</artifactId>
		<configuration>
			<annotationProcessorPaths>
				<path>
					<groupId>org.hibernate.orm</groupId>
					<artifactId>hibernate-jpamodelgen</artifactId>
					<version>${hibernate.version}</version>
				</path>
				<path>
					<groupId>com.querydsl</groupId>
					<artifactId>querydsl-apt</artifactId>
					<version>${querydsl.version}</version>
					<classifier>jakarta</classifier>
				</path>
				<path>
					<groupId>org.projectlombok</groupId>
					<artifactId>lombok</artifactId>
					<version>${lombok.version}</version>
				</path>
			</annotationProcessorPaths>
		</configuration>
	</plugin>
</plugins>

参阅GitHub上SAT项目的相关变更。

由于hibernate-jpamodelgen的限制，我们不得不将此方法应用于所有紧密依赖于注解处理的依赖项（如querydsl-apt或lombok）。例如，当未按此方式使用lombok时，会遇到如下编译错误：

Plain Text

  

[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] <SAT_PATH>\sat-jpa\src\main\java\com\github\aha\sat\jpa\city\CityService.java:[15,30] error: variable repository not initialized in the default constructor
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  4.535 s
[INFO] Finished at: 2024-01-08T08:40:29+01:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.11.0:compile (default-compile) on project sat-jpa: Compilation failure
[ERROR] <SAT_PATH>\sat-jpa\src\main\java\com\github\aha\sat\jpa\city\CityService.java:[15,30] error: variable repository not initialized in the default constructor

同样的情况也适用于querydsl-apt，此时会遇到如下编译错误：

Plain Text

  

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  5.211 s
[INFO] Finished at: 2024-01-11T08:39:18+01:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.11.0:compile (default-compile) on project sat-jpa: Compilation failure: Compilation failure: 
[ERROR] <SAT_PATH>\sat-jpa\src\main\java\com\github\aha\sat\jpa\country\CountryRepository.java:[3,44] error: cannot find symbol
[ERROR]   symbol:   class QCountry
[ERROR]   location: package com.github.aha.sat.jpa.country
[ERROR] <SAT_PATH>\sat-jpa\src\main\java\com\github\aha\sat\jpa\country\CountryRepository.java:[3] error: static import only from classes and interfaces
[ERROR] <SAT_PATH>\sat-jpa\src\main\java\com\github\aha\sat\jpa\country\CountryCustomRepositoryImpl.java:[3,41] error: cannot find symbol
[ERROR]   symbol:   class QCity
[ERROR]   location: package com.github.aha.sat.jpa.city
[ERROR] <SAT_PATH>\sat-jpa\src\main\java\com\github\aha\sat\jpa\country\CountryCustomRepositoryImpl.java:[3] error: static import only from classes and interfaces
[ERROR] <SAT_PATH>\sat-jpa\src\main\java\com\github\aha\sat\jpa\country\CountryCustomRepositoryImpl.java:[4,44] error: cannot find symbol
[ERROR]   symbol:   class QCountry
[ERROR]   location: package com.github.aha.sat.jpa.country
[ERROR] <SAT_PATH>\sat-jpa\src\main\java\com\github\aha\sat\jpa\country\CountryCustomRepositoryImpl.java:[4] error: static import only from classes and interfaces
[ERROR] -> [Help 1]

原因显而易见，我们需要同时应用所有注解处理器，否则某些代码片段可能会缺失，从而导致编译错误。

重新设计的Unpaged

第二个小问题是关于Unpaged类的改动。将Unpaged从enum改为class影响了PageImpl通过Jackson库的序列化（参见spring-projects/spring-data-commons#2987）。

  • Spring Boot 3.1.6:
Java

  

public interface Pageable {

	static Pageable unpaged() {
		return Unpaged.INSTANCE;
	}

	...
}

enum Unpaged implements Pageable {

	INSTANCE;

	...
}

  • Spring Boot 3.2.2:
Java

  

public interface Pageable {

	static Pageable unpaged() {
		return unpaged(Sort.unsorted());
	}

	static Pageable unpaged(Sort sort) {
		return Unpaged.sorted(sort);
	}

	...
}
	
final class Unpaged implements Pageable {

	private static final Pageable UNSORTED = new Unpaged(Sort.unsorted());

	...

}

当使用new PageImpl<City>(cities)（我们习惯的方式）时，会抛出此错误：

Plain Text

  

2024-01-11T08:47:56.446+01:00  WARN 5168 --- [sat-elk] [           main] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.http.converter.HttpMessageNotWritableException: Could not write JSON: (was java.lang.UnsupportedOperationException)]

MockHttpServletRequest:
      HTTP Method = GET
      Request URI = /api/cities/country/Spain
       Parameters = {}
          Headers = []
             Body = null
    Session Attrs = {}

Handler:
             Type = com.github.aha.sat.elk.city.CityController
           Method = com.github.aha.sat.elk.city.CityController#searchByCountry(String, Pageable)

Async:
    Async started = false
     Async result = null

Resolved Exception:
             Type = org.springframework.http.converter.HttpMessageNotWritableException

解决方法是使用包含所有属性的构造器，如下所示：

Java

  

new PageImpl<City>(cities, ofSize(PAGE_SIZE), cities.size())

而非：

Java

  

new PageImpl<City>(cities)

注意：预计在Spring Boot 3.3中修复此问题（参见此问题评论）。

结论

本文涵盖了升级至撰写本文时的最新版Spring Boot 3.2.2过程中遇到的问题。文章首先探讨了因Hibernate依赖管理变更导致的注解处理器处理方式的调整。接着，阐述了Unpaged类的改动及使用PageImpl的替代方案。

所有这些变更（以及其他一些变动）均可在PR #64中查看。上述完整示例代码已上传至我的GitHub仓库。

Source:
https://dzone.com/articles/upgrade-guide-to-spring-boot-32-for-spring-data-jp