弹簧数据休息场转换器 [英] Spring Data Rest Field converter
问题描述
我很难在 spring数据REST项目（控制器免费应用程序和严格的java配置）上使用我的自定义转换器。
我有两个实体，一个员工和一个州。这种关系是@ManyToOne，我相信大家都知道。无论如何，问题是将 state 字段（字段名称是状态）从 String 转换为状态对象和 setState（）在 Employee 类中，用于数据库的持久性。
I have two Entities, an Employee and a State. The relationship is @ManyToOne, I am sure we all know that. Anyway, the problem is converting the state field (field name is state) from String to a State object and setState() in the Employee class for persistence to a database.
package com.hr.domain;
@Entity
public class Employee implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "state_id", nullable = true)
private Long id;
private String firstname;
private State state;
@StateConverter
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "employee_state_id_fk", nullable = false, insertable = true, updatable = true)
private State state;
//GETTERS AND SETTERS
public String getFirstname() {
return firstname();
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
public String getState() {
return state();
}
public void setState(State state) {
this.state = state;
}
//HASHCODES AND EQUALS
}
package com.hr.domain;
@Entity
public class State implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "state_id", nullable = true)
private Long id;
private String state_name;
//GETTERS AND SETTERS
//TO STRING
@Override
public String toString() {
return "State [id=" + id + ", state_name=" + state_name + "]";
}
}
我已经注册了我的转换器转换服务，但仍然无法将String转换为表单提交上的State对象。
I have registered my converter with the conversion service but still cant get the String to be converter to State object on form submit.
@Bean//(name="conversionService")
public ConversionService getConversionService() {
ConversionServiceFactoryBean bean = new ConversionServiceFactoryBean();
bean.setConverters(getConverters());
bean.afterPropertiesSet();
ConversionService object = bean.getObject();
System.out.println(object);
return object;
}
private Set<Converter> getConverters() {
Set<Converter> converters = new HashSet<Converter>();
converters.add(new StringToStateTypeConverter());
return converters;
}
这是我的StateConverter
This is my StateConverter
@Component
@StateConverter
public class StringToStateTypeConverter implements Converter<String, State> {
@Autowired
StateRepository repository;
public State convert(String source) {
return repository.findOne(new Long(source));
}
}
提交时，我收到此错误：
On submission, I get this error:
引起：org.springframework.core.convert.ConversionFailedException：无法从类型java.net.URI转换为com类型。 hr.domain.State表示值'AB';
Caused by: org.springframework.core.convert.ConversionFailedException: Failed to convert from type java.net.URI to type com.hr.domain.State for value 'AB';
任何形式的帮助都将受到赞赏。
Any form of help will be appreciated.
力量可以跟你一起
问候。
May the force be with you Regards.
这是错误跟踪
17:21:29,975 ERROR [org.springframework.data.rest.webmvc.AbstractRepositoryRestController] (default task-13) Could not read JSON: Failed to convert from type java.net.URI to type com.hr.domain.State for value 'AB'; nested exception is java.lang.IllegalArgumentException: Cannot resolve URI AB. Is it local or remote? Only local URIs are resolvable. (through reference chain: com.hr.domain.Employee["State"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: Failed to convert from type java.net.URI to type com.hr.domain.State for value 'AB'; nested exception is java.lang.IllegalArgumentException: Cannot resolve URI AB. Is it local or remote? Only local URIs are resolvable. (through reference chain: com.hr.domain.Employee["State"]): org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Failed to convert from type java.net.URI to type com.hr.domain.State for value 'AB'; nested exception is java.lang.IllegalArgumentException: Cannot resolve URI AB. Is it local or remote? Only local URIs are resolvable. (through reference chain: com.hr.domain.Employee["State"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: Failed to convert from type java.net.URI to type com.hr.domain.State for value 'AB'; nested exception is java.lang.IllegalArgumentException: Cannot resolve URI AB. Is it local or remote? Only local URIs are resolvable. (through reference chain: com.hr.domain.Employee["State"])
at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.readJavaType(MappingJackson2HttpMessageConverter.java:228) [spring-web-4.0.5.RELEASE.jar:4.0.5.RELEASE]
...........
Caused by: com.fasterxml.jackson.databind.JsonMappingException: Failed to convert from type java.net.URI to type com.hr.domain.State for value 'AB'; nested exception is java.lang.IllegalArgumentException: Cannot resolve URI AB. Is it local or remote? Only local URIs are resolvable. (through reference chain: com.hr.domain.Employee["State"])
at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:232) [jackson-databind-2.3.3.jar:2.3.3]
at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:197) [jackson-databind-2.3.3.jar:2.3.3]
Caused by: org.springframework.core.convert.ConversionFailedException: Failed to convert from type java.net.URI to type com.hr.domain.State for value 'AB'; nested exception is java.lang.IllegalArgumentException: Cannot resolve URI AB. Is it local or remote? Only local URIs are resolvable.
at org.springframework.data.rest.core.UriToEntityConverter.convert(UriToEntityConverter.java:106) [spring-data-rest-core-2.1.0.RELEASE.jar:]
at org.springframework.data.rest.webmvc.json.PersistentEntityJackson2Module$UriStringDeserializer.deserialize(PersistentEntityJackson2Module.java:359) [spring-data-rest-webmvc-2.1.0.RELEASE.jar:]
Caused by: java.lang.IllegalArgumentException: Cannot resolve URI AB. Is it local or remote? Only local URIs are resolvable.
... 94 more
推荐答案
你是注册新的 ConversionService 。它取代了弹簧在默认情况下注册的默认值，通常假定存在许多转换器。并且您创建了一个新的转换器，而不是使用您配置的bean。你应该改为：
You a registering a new ConversionService. It replaces the default one that spring registers by default with a lot of converters that are generally assumed to be present. And you create a new converter instead of using your configured bean. You should instead :
- 注册spring的默认转换服务及其所有默认转换器
- add转换为这个
您的转换服务初始化可能如下所示：
Your conversion service initialization could look like :
private @Autowired StringToStateTypeConverter stringToStateTypeConverter;
@Bean//(name="conversionService")
public ConversionService getConversionService() {
ConversionServiceFactoryBean bean = new DefaultFormattingConversionService();
bean.addConverter(String.class, State.class, stringToStateTypeConverter);
return bean;
}
编辑
由于错误来自从 URI 转换为 State 的问题，您可以尝试从URI添加转换器状态（假设您的存储库有一个 findByName 方法，以名称 c> c>来查找州 code>：
As the error come from a problem of conversion from URI to State, you could try to add a converter from URI to State (assuming your repository has a method findByName to find a State by its name:
@Component
@StateConverter
public class URIToStateTypeConverter implements Converter<URI, State> {
@Autowired
StateRepository repository;
public State convert(URI uri) {
String source = uri.toString();
try {
long id = Long.valueOf(source);
return repository.findOne(id);
} catch (NumberFormatException e) { // should be a name ??
return repository.findByName(source);
}
}
}
转换服务初始化将变为：
And the conversion service initialization would become :
private @Autowired StringToStateTypeConverter stringToStateTypeConverter;
private @Autowired URIToStateTypeConverter uriToStateTypeConverter;
@Bean//(name="conversionService")
public ConversionService getConversionService() {
ConversionServiceFactoryBean bean = new DefaultFormattingConversionService();
bean.addConverter(String.class, State.class, stringToStateTypeConverter);
bean.addConverter(URI.class, State.class, uriToStateTypeConverter);
return bean;
}
但我不确定它是否会被spring-data使用 - 休息
But I'm not sure if it will be used by spring-data-rest
这篇关于弹簧数据休息场转换器的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
