以下是我使用的解决方案:
@Entity
@Table(name = "SOLUTION")
public class Solution implements Serializable {
private static final long serialVersionUID = 745945642089325612L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "ID", nullable = false, updatable = false, columnDefinition = "INT")
private Long id;
@Column(name = "NAME", nullable = false, columnDefinition = "VARCHAR(100)")
private String name;
// Fetch eagerly to make serialization easy
@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(name = SolTagMap.TABLE_NAME, //
joinColumns = { @JoinColumn(name = SolTagMap.SOL_ID_COL_NAME) }, //
inverseJoinColumns = { @JoinColumn(name = SolTagMap.TAG_ID_COL_NAME) })
private Set<Tag> tags = new HashSet<>(0);
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Set<Tag> getTags() {
return tags;
}
public void setTags(Set<Tag> tags) {
this.tags = tags;
}
@Override
public String toString() {
return this.getClass().getName() + "[id=" + getId() + ", name=" + getName() + ", tags="
+ getTags() + "]";
}
}
实体地图表
@Entity
@IdClass(SolTagMapKey.class)
@Table(name = SolTagMap.TABLE_NAME)
public class SolTagMap implements Serializable {
// Define constants so names can be reused in many-many annotation.
/* package */ static final String TABLE_NAME = "SOL_TAG_MAP";
/* package */ static final String SOL_ID_COL_NAME = "SOL_ID";
/* package */ static final String TAG_ID_COL_NAME = "TAG_ID";
private static final long serialVersionUID = -7814665924253912856L;
@Embeddable
public static class SolTagMapKey implements Serializable {
private static final long serialVersionUID = -503957020456645384L;
private Long solId;
private Long tagId;
@Override
public boolean equals(Object that) {
if (that == null)
return false;
if (!(that instanceof SolTagMapKey))
return false;
SolTagMapKey thatPK = (SolTagMapKey) that;
return Objects.equals(solId, thatPK.solId) && Objects.equals(tagId, thatPK.tagId);
}
@Override
public int hashCode() {
return Objects.hash(solId, tagId);
}
@Override
public String toString() {
return this.getClass().getName() + "[solId=" + solId + ", tagId=" + tagId + "]";
}
}
@Id
@Column(name = SolTagMap.SOL_ID_COL_NAME, nullable = false, updatable = false, columnDefinition = "INT")
private Long solId;
@Id
@Column(name = SolTagMap.TAG_ID_COL_NAME, nullable = false, updatable = false, columnDefinition = "INT")
private Long tagId;
public Long getSolId() {
return solId;
}
public void setSolId(Long solId) {
this.solId = solId;
}
public Long getTagId() {
return tagId;
}
public void setTagId(Long tagId) {
this.tagId = tagId;
}
@Override
public boolean equals(Object that) {
if (that == null)
return false;
if (!(that instanceof SolTagMap))
return false;
SolTagMap thatObj = (SolTagMap) that;
return Objects.equals(solId, thatObj.solId) && Objects.equals(tagId, thatObj.tagId);
}
@Override
public int hashCode() {
return Objects.hash(solId, tagId);
}
@Override
public String toString() {
return this.getClass().getName() + "[solId=" + solId + ", tagId=" + tagId + "]";
}
}
实体标签
@Entity
@Table(name = "TAG")
public class Tag implements Serializable {
private static final long serialVersionUID = -288462280366502647L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "ID", nullable = false, updatable = false, columnDefinition = "INT")
private Long id;
@Column(name = "NAME", nullable = false, columnDefinition = "VARCHAR(100)")
private String name;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public boolean equals(Object that) {
if (that == null)
return false;
if (!(that instanceof Tag))
return false;
Tag thatObj = (Tag) that;
return Objects.equals(id, thatObj.id);
}
@Override
public int hashCode() {
return Objects.hash(id, name);
}
@Override
public String toString() {
return this.getClass().getName() + "[id=" + id + ", name=" + name + "]";
}
}
搜索服务实施
@Service("simpleSolutionSearchService")
@Transactional
public class SimpleSolutionSearchServiceImpl implements SimpleSolutionSearchService {
@Autowired
private SessionFactory sessionFactory;
// This works fine
public List<Solution> findSolutions() {
Criteria criteria = sessionFactory.getCurrentSession().createCriteria(Solution.class);
// Hibernate should coalesce the results, yielding only solutions
criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
return criteria.list();
}
// This throws
public List<Solution> findSolutionsWithTags(String[] requiredTags) {
final String parentAlias = "sol";
final String collFieldAlias = "t";
final String tagValueField = collFieldAlias + ".name";
DetachedCriteria subquery = DetachedCriteria.forClass(Solution.class)
.add(Restrictions.eqProperty("id", parentAlias + ".id"))
.createAlias("tags", collFieldAlias) //
.add(Restrictions.in(tagValueField, requiredTags)) //
.setProjection(Projections.count(tagValueField));
Criteria criteria = sessionFactory.getCurrentSession().createCriteria(Solution.class, parentAlias)
.add(Subqueries.eq((long) requiredTags.length, subquery));
criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
return criteria.list();
}
}
解决方案库
public interface SimpleSolutionRepository extends CrudRepository<Solution, Long> {
}
标记存储库
public interface SimpleTagRepository extends CrudRepository<Tag, Long> {
}
测试用例
@RunWith(SpringRunner.class)
@SpringBootTest
public class SolutionServiceTest {
private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
@Autowired
private SimpleSolutionRepository solutionRepository;
@Autowired
private SimpleTagRepository tagRepository;
@Autowired
private SimpleSolutionSearchService searchService;
@Test
public void testRepositories() throws Exception {
final String tagName1 = "tag name 1";
final String tagName2 = "tag name 2";
Tag t1 = new Tag();
t1.setName(tagName1);
t1 = tagRepository.save(t1);
Assert.assertNotNull(t1.getId());
logger.info("Created tag {}", t1);
Tag t2 = new Tag();
t2.setName(tagName2);
t2 = tagRepository.save(t2);
Assert.assertNotNull(t2.getId());
logger.info("Created tag {}", t2);
Solution s1 = new Solution();
s1.setName("solution one tag");
s1.getTags().add(t1);
s1 = solutionRepository.save(s1);
Assert.assertNotNull(s1.getId());
logger.info("Created solution {}", s1);
Solution s2 = new Solution();
s2.setName("solution two tags");
s2.getTags().add(t1);
s2.getTags().add(t2);
s2 = solutionRepository.save(s2);
Assert.assertNotNull(s2.getId());
logger.info("Created solution {}", s1);
List<Solution> sols = searchService.findSolutions();
Assert.assertTrue(sols.size() == 2);
for (Solution s : sols)
logger.info("Found solution {}", s);
String[] searchTags = { tagName1, tagName2 };
List<Solution> taggedSols = searchService.findSolutionsWithTags(searchTags);
// EXPECT ONE OBJECT BUT GET ZERO
Assert.assertTrue(taggedSols.size() == 1);
}
}
发布于 2018-08-30 12:08:49
这样试试:
public List<Solution> findSolutionsWithTags(String[] requiredTags) {
final String parentAlias = "sol";
final String childAlias = "subSol";
final String collFieldAlias = "t";
final String tagValueField = collFieldAlias + ".name";
DetachedCriteria subquery = DetachedCriteria.forClass(Solution.class, childAlias)
// Throws ClassCastException; apparently sol.id isn't replaced with an ID value?
// Problem should be due to following line
//.add(Restrictions.eq("id", parentAlias + ".id"))
// Use eqProperty instead
.add(Restrictions.eqProperty(childAlias + ".id", parentAlias + ".id"))
.createAlias("tags", collFieldAlias) //
.add(Restrictions.in(tagValueField, requiredTags)) //
.setProjection(Projections.count(tagValueField));
Criteria criteria = sessionFactory.getCurrentSession().createCriteria(Solution.class, parentAlias)
.add(Subqueries.eq((long) requiredTags.length, subquery));
criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
return criteria.list();
}
https://stackoverflow.com/questions/-100008831
复制相似问题