spring 用休眠休息延迟加载
spring rest lazy loading with hibernate
我正在尝试使用休眠开发 spring 休息 api。
在 google 中搜索后,我还没有找到延迟加载的解决方案。
我有如下两个实体:
University.java
@Entity()
@Table(schema = "core", name = "university")
public class University extends BaseEntity {
private String uniName;
private String uniTelephon;
@LazyCollection(LazyCollectionOption.FALSE)
@OneToMany(fetch = FetchType.LAZY, mappedBy = "university", cascade = CascadeType.ALL)
@JsonManagedReference
private List<Student> students;
//setter and getter
}
Student.java
@Entity
@Table(schema = "core",name = "student")
public class Student {
@Id
@GeneratedValue
private long id;
private String firstName;
private String lastName;
private String section;
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name = "UNIVERSITY_ID",nullable = false)
@JsonBackReference
private University university;
// setter and getter
}
任何我的休息终点
@GetMapping("/list")
public ResponseEntity list() throws Exception {
// I need to return just Universities But it return it eagerly with their students
return new ResponseEntity(this.universityService.findAll(), HttpStatus.OK);
}
在调用其余 api 之后,它 return 与所有学生一起上大学。
有没有办法告诉 Jackson 不要序列化未获取的对象或集合?
有人可以帮助我提供经过验证的解决方案吗?
尝试添加以下依赖项(取决于您的休眠版本):
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-hibernate5</artifactId>
<version>${jackson.version}</version>
</dependency>
然后(假设您有一个基于 Java 的配置)在 WebMvcConfigurerAdapter class 中添加以下内容:
@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
converters.add(jackson2HttpMessageConverter());
}
@Bean
public MappingJackson2HttpMessageConverter jackson2HttpMessageConverter() {
MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
converter.setObjectMapper(this.jacksonBuilder().build());
return converter;
}
public Jackson2ObjectMapperBuilder jacksonBuilder() {
Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
Hibernate5Module hibernateModule = new Hibernate5Module();
hibernateModule.configure(Feature.FORCE_LAZY_LOADING, false);
builder.modules(hibernateModule);
// Spring MVC default Objectmapper configuration
builder.featuresToDisable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
builder.featuresToDisable(MapperFeature.DEFAULT_VIEW_INCLUSION);
return builder;
}
它应该强制 Jackson 的 objectMapper 不获取延迟加载的值。
我正在尝试使用休眠开发 spring 休息 api。 在 google 中搜索后,我还没有找到延迟加载的解决方案。 我有如下两个实体:
University.java
@Entity()
@Table(schema = "core", name = "university")
public class University extends BaseEntity {
private String uniName;
private String uniTelephon;
@LazyCollection(LazyCollectionOption.FALSE)
@OneToMany(fetch = FetchType.LAZY, mappedBy = "university", cascade = CascadeType.ALL)
@JsonManagedReference
private List<Student> students;
//setter and getter
}
Student.java
@Entity
@Table(schema = "core",name = "student")
public class Student {
@Id
@GeneratedValue
private long id;
private String firstName;
private String lastName;
private String section;
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name = "UNIVERSITY_ID",nullable = false)
@JsonBackReference
private University university;
// setter and getter
}
任何我的休息终点
@GetMapping("/list")
public ResponseEntity list() throws Exception {
// I need to return just Universities But it return it eagerly with their students
return new ResponseEntity(this.universityService.findAll(), HttpStatus.OK);
}
在调用其余 api 之后,它 return 与所有学生一起上大学。
有没有办法告诉 Jackson 不要序列化未获取的对象或集合?
有人可以帮助我提供经过验证的解决方案吗?
尝试添加以下依赖项(取决于您的休眠版本):
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-hibernate5</artifactId>
<version>${jackson.version}</version>
</dependency>
然后(假设您有一个基于 Java 的配置)在 WebMvcConfigurerAdapter class 中添加以下内容:
@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
converters.add(jackson2HttpMessageConverter());
}
@Bean
public MappingJackson2HttpMessageConverter jackson2HttpMessageConverter() {
MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
converter.setObjectMapper(this.jacksonBuilder().build());
return converter;
}
public Jackson2ObjectMapperBuilder jacksonBuilder() {
Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
Hibernate5Module hibernateModule = new Hibernate5Module();
hibernateModule.configure(Feature.FORCE_LAZY_LOADING, false);
builder.modules(hibernateModule);
// Spring MVC default Objectmapper configuration
builder.featuresToDisable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
builder.featuresToDisable(MapperFeature.DEFAULT_VIEW_INCLUSION);
return builder;
}
它应该强制 Jackson 的 objectMapper 不获取延迟加载的值。