我正在尝试跟随Josh Long - Philip Sorst example以使用Neo4J作为db执行Angular SPA-Rest身份验证和CRUD操作(出色的工作。非常感谢你们)。但是我很早就陷入了困境,我怀疑这不是我的错。请帮助Neo4J-Angular-Spring爱好者。我的代码可以找到here,只需克隆并运行mvn spring-boot:run
现在问题是我只为GraphRepository的findAll()方法获得以下异常。
Caused by: java.lang.NullPointerException: null
at org.neo4j.kernel.TopLevelTransaction.markAsRollbackOnly(TopLevelTransaction.java:93)
... 88 common frames omitted
我会复制一些代码:
Neo4JConfig.java
@Configuration
@EnableNeo4jRepositories(basePackages = "demo.repository.neo4j")
public class Neo4JConfig extends Neo4jConfiguration {
public Neo4JConfig() {
setBasePackage("demo.model.neo4j");
}
@Bean(destroyMethod = "shutdown")
public GraphDatabaseService graphDatabaseService() {
return new GraphDatabaseFactory().newEmbeddedDatabase("data/demo.db");
}
@Bean
public Neo4jTemplate neo4jTemplate() {
return new Neo4jTemplate(graphDatabaseService());
}
}
NewsEntry.java
@NodeEntity
public class NewsEntry {
@GraphId
private Long id;
private String content;
public NewsEntry() {}
public NewsEntry(String b) {
this.content = b;
}
public Long getId() {
return this.id;
}
public String getContent() {
return this.content;
}
public void setId(Long id) {
this.id = id;
}
public void setContent(String content) {
this.content = content;
}
}
NewsEntryRepository.java
public interface NewsEntryRepository extends GraphRepository<NewsEntry> {
}
NewsEntryController.java
@RestController
class NewsController {
@Autowired
private NewsEntryRepository newsEntryRepository;
@RequestMapping("/news")
List<NewsEntry> entries() {
List<NewsEntry> list = new ArrayList<NewsEntry>();
Iterable<NewsEntry> results = newsEntryRepository.findAll();
for (NewsEntry r : results) {
list.add(r);
}
return list;
}
@RequestMapping(value = "/news/{id}", method = RequestMethod.DELETE)
void remove(@PathVariable Long id) {
this.newsEntryRepository.delete(id);
return;
}
@RequestMapping(value = "/news/{id}", method = RequestMethod.GET)
NewsEntry entry(@PathVariable Long id) {
return this.newsEntryRepository.findOne(id);
}
@RequestMapping(value = "/news/{id}", method = RequestMethod.POST)
NewsEntry update(@PathVariable Long id, @RequestBody NewsEntry news) {
NewsEntry old = this.newsEntryRepository.findOne(id);
old = news;
return this.newsEntryRepository.save(old);
}
@RequestMapping(value = "/news", method = RequestMethod.POST)
NewsEntry add(@RequestBody NewsEntry news) {
this.newsEntryRepository.save(new NewsEntry(news.getContent()));
return news;
}
}
答案 0 :(得分:2)
OK解决方案受到启发https://github.com/mstahv/bootiful-neo4j-with-vaadin/blob/master/src/main/java/org/vaadin/neo4j/AppService.java。在使用控制器中的存储库之前,他正在实现使用@Transactional注释的@Service。
答案 1 :(得分:0)
您不必覆盖:
@Bean
public Neo4jTemplate neo4jTemplate() {
return new Neo4jTemplate(graphDatabaseService());
}
您可以尝试添加注释:
@EnableTransactionManagement
到您的配置?
答案 2 :(得分:0)
有些东西告诉我,解决方案隐藏在某个地方here。我会试一试,让你知道。
确定仅当您将Spring-data-neo4j的版本更改为2.3.3.RELEASE时才有效。如果您使用的是最新版本,则会遇到与上述相同的问题。我想我应该开个问题。
但那不是解决方案,因为我想使用Neo4J Server Community 2.0.3打开图表进行可视化。另外我不明白这个解决方案beanfactories,注入而不是autowired ???。但是我会在我的github repo中为这个解决方案创建另一个分支。