java - 当结果是一条记录时，Hibernate Search/Lucene 返回 null 元素

Question

我在 Hibernate Search 和 Lucene 方面遇到了一个奇怪的问题。我相信这个问题有点简单:当我搜索返回多个记录的内容时，一切正常。当我搜索仅返回一条记录的内容时，实体元素全部为 null，但是当我调用 toString() 方法时，一切都在那里。

我的实体:

import java.io.Serializable;
import java.sql.Blob;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

import org.hibernate.search.annotations.Analyze;
import org.hibernate.search.annotations.Field;
import org.hibernate.search.annotations.Index;
import org.hibernate.search.annotations.Indexed;
import org.hibernate.search.annotations.Store;

@Entity
@Indexed
@Table(name = "vw_colaborador", schema = "col")
public class Colaborador implements Serializable {

    private static final long serialVersionUID = 886370076152195975L;

    @Id
    @Column(name = "id", insertable = false, updatable = false)
    private Long id;

    @Column(name = "matricula", insertable = false, updatable = false)
    @Field(store = Store.NO, index = Index.YES, analyze = Analyze.YES)
    private String matricula;

    @Field(store = Store.NO, index = Index.YES, analyze = Analyze.YES)
    @Column(name = "nome", insertable = false, updatable = false)
    private String nome;

    @Field(store = Store.NO, index = Index.YES, analyze = Analyze.YES)
    @Column(name = "email", insertable = false, updatable = false)
    private String email;

    @Column(name = "foto", insertable = false, updatable = false)
    private Blob foto;

    @Field(store = Store.NO, index = Index.YES, analyze = Analyze.YES)
    @Column(name = "login", insertable = false, updatable = false)
    private String login;

    @Field(store = Store.YES, index = Index.YES, analyze = Analyze.YES)
    @Column(name = "ramal", insertable = false, updatable = false)
    private String ramal;

    @Field(store = Store.NO, index = Index.YES, analyze = Analyze.YES)
    @Column(name = "hierarquia_ua", insertable = false, updatable = false)
    private String ua;

    @Column(name = "situacao_id", insertable = false, updatable = false)
    private Long situacaoId;

    @Column(name = "situacao", insertable = false, updatable = false)
    private String situacao;

    @Column(name = "vinculo_id", insertable = false, updatable = false)
    private Long vinculoId;

    @Column(name = "vinculo", insertable = false, updatable = false)
    private String vinculo;

    @Field(store = Store.NO, index = Index.YES, analyze = Analyze.YES)
    @Column(name = "diretoria", insertable = false, updatable = false)
    private String diretoria;

    @Field(store = Store.NO, index = Index.YES, analyze = Analyze.YES)
    @Column(name = "sigla_diretoria", insertable = false, updatable = false)
    private String siglaDiretoria;

    @Field(store = Store.NO, index = Index.YES, analyze = Analyze.YES)
    @Column(name = "sala", insertable = false, updatable = false)
    private String sala;

    @Field(store = Store.NO, index = Index.YES, analyze = Analyze.YES)
    @Column(name = "predio", insertable = false, updatable = false)
    private String predio;

    //... getters and setters ommited

    @Override
    public String toString() {
    return "Colaborador [id=" + id + ", matricula=" + matricula + ", nome=" + nome + ", email=" + email + ", foto=" + foto + ", login=" + login + ", ramal=" + ramal + ", ua="
        + ua + ", situacaoId=" + situacaoId + ", situacao=" + situacao + ", vinculoId=" + vinculoId + ", vinculo=" + vinculo + ", diretoria=" + diretoria
        + ", siglaDiretoria=" + siglaDiretoria + ", sala=" + sala + ", predio=" + predio + "]";
    }
}

还有我的 DAO，我在其中使用 Hibernate Search 进行搜索...

ColaboradorDAO(由 Spring 管理)

import java.util.List;

import javax.persistence.TypedQuery;

import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.hibernate.search.jpa.FullTextEntityManager;
import org.hibernate.search.jpa.FullTextQuery;
import org.hibernate.search.jpa.Search;
import org.hibernate.search.query.dsl.QueryBuilder;
import org.springframework.stereotype.Repository;

@Repository("colaboradorDAO")
public class ColaboradorDAO extends AbstractDAO<Colaborador, Long> {

    private static final Logger logger = LogManager.getLogger(ColaboradorDAO.class);

    @SuppressWarnings("unchecked")
    public List<Colaborador> filtrar(Object termo) throws DAOException {
    try {
        FullTextEntityManager fullTextEm = Search.getFullTextEntityManager(this.entityManager);
        QueryBuilder qb = fullTextEm.getSearchFactory().buildQueryBuilder().forEntity(Colaborador.class).get();

        Query query = qb.keyword()
            .onFields("matricula", "nome", "email", "login", "ramal", "ua", "diretoria", "siglaDiretoria", "sala", "predio")
            .matching(termo)
            .createQuery();

        FullTextQuery fullTextQuery = fullTextEm.createFullTextQuery(query);
        Sort sortField = new Sort(new SortField("nome", SortField.STRING));
        fullTextQuery.setSort(sortField);
        return fullTextQuery.getResultList();
    }
    catch (Exception e) {
        logger.error("Erro ao filtrar colaboradores com termo: " + termo, e);
        throw new DAOException(e);
    }
    }

    public void indexar() throws DAOException {
        FullTextEntityManager fullTextEntityManager = Search.getFullTextEntityManager(this.entityManager);

        try {
            fullTextEntityManager.createIndexer().startAndWait();
        }
        catch (InterruptedException e) {
            logger.error("Erro ao criar indice de busca dos colaboradores", e);
            throw new DAOException(e);
        }
    }
}

当我调用 filtrar(String termo) 方法时，它就像一个魅力一样，没有错误，也没有异常。但是，当我查询的结果只有一条记录时，Colaborador 实体会被实例化，但所有元素均为 null。

示例:

@Test
public void testColaborador() {
    try {
        List<Colaborador> listColaborador = this.colaboradorService.filtrar("060091");
        for (Colaborador c : listColaborador) {
            System.out.println(c.getNome());
        }
    }
    catch (ServiceException e) {
        e.printStackTrace();
    }
}

结果:

null

如果我将行: System.out.println(c.getNome()); 更改为 System.out.println(c.toString());然后，非常适合打印所有元素。

我正在使用:

• Hibernate 搜索 4.3.0.Final；
• Hibernate 核心 4.2.2.Final；
• Spring 3.2.3.RELEASE；
• Lucene 3.6.2；

更新我的问题:

我已将 Hibernate Search 版本升级到 4.4.0.Alpha1，但错误仍然存​​在。我还意识到我的实体与“延迟加载”有关。当我检查实体时，所有属性均为 null，但还有另一个名为 JavassistLazyInitializer 的属性。

Answer 1

好了，问题解决了!我无法对实体上的方法 getter 和 setter 使用 final 关键字。当我注释 getter 而不是 private 字段时，就像 @Sanne 所说，此错误消息显示在控制台上:

ERROR PojoEntityTuplizer:201 - HHH000112: Getters of lazy classes cannot be final

然后，我删除了我的实体 Colaborador 的所有最终关键字，并且成功了!所以，我改回了私有(private)字段的注释，它仍然有效!

谢谢!