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hibernate的envers模塊提供了一整套機(jī)制可以用來記錄數(shù)據(jù)的變更仰剿。這里簡單介紹一下全陨。

1.自動(dòng)配置

@SpringBootApplication
@EnableJpaRepositories(repositoryFactoryBeanClass = EnversRevisionRepositoryFactoryBean.class)
@EnableJpaAuditing(auditorAwareRef = "auditorAwareImpl")
public class EnversDemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(EnversDemoApplication.class, args);
    }
}

這里配置@EnableJpaRepositories(repositoryFactoryBeanClass = EnversRevisionRepositoryFactoryBean.class)表示開啟envers模塊。

2.Audited注解

@Entity
@Audited
public class Book extends AuditableEntity{

    @javax.persistence.Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private String title;

    private String author;

    private String description;

    private long price;

    private boolean valid;

    // getter and setter
}

使用@Audited標(biāo)注一下這個(gè)實(shí)體類需要審計(jì)甚颂。

繼承RevisionRepository

public interface BookDao extends RevisionRepository<Book, Long, Integer>,JpaRepository<Book, Long> {
}

通過繼承RevisionRepository獲取查找revisions的查詢方法蜜猾，主要如下：

@NoRepositoryBean
public interface RevisionRepository<T, ID extends Serializable, N extends Number & Comparable<N>> {
    Revision<N, T> findLastChangeRevision(ID var1);

    Revisions<N, T> findRevisions(ID var1);

    Page<Revision<N, T>> findRevisions(ID var1, Pageable var2);

    Revision<N, T> findRevision(ID var1, N var2);
}

這里的N是指變更版本號(hào)的類型，一般Integer夠用振诬，如果覺得不夠用可以改為Long類型蹭睡。這里的T就是實(shí)體類。ID就是實(shí)體類的主鍵類型贷揽。

查詢變更

經(jīng)過以上配置之后棠笑，就可以正常記錄變更的每個(gè)版本了，可以通過如下方法來查詢禽绪，比如：

Revisions<Integer,Book> revision = bookDao.findRevisions(id);
List<Revision<Integer,Book>> data = revision.getContent();

這里的id為實(shí)體的id

revision的表結(jié)構(gòu)

hibernate默認(rèn)以實(shí)體類后綴_AUD來記錄每個(gè)變更的版本蓖救，比如

-- ----------------------------
--  Table structure for book_aud
-- ----------------------------
DROP TABLE IF EXISTS "public"."book_aud";
CREATE TABLE "public"."book_aud" (
    "id" int8 NOT NULL,
    "rev" int4 NOT NULL,
    "revtype" int2,
    "author" varchar(255) COLLATE "default",
    "description" varchar(255) COLLATE "default",
    "price" int8,
    "title" varchar(255) COLLATE "default",
    "valid" bool
)
WITH (OIDS=FALSE);
ALTER TABLE "public"."book_aud" OWNER TO "postgres";

-- ----------------------------
--  Primary key structure for table book_aud
-- ----------------------------
ALTER TABLE "public"."book_aud" ADD PRIMARY KEY ("id", "rev") NOT DEFERRABLE INITIALLY IMMEDIATE;

-- ----------------------------
--  Foreign keys structure for table book_aud
-- ----------------------------
ALTER TABLE "public"."book_aud" ADD CONSTRAINT "fk2u9iq76nh69r6f989ae7xft9" FOREIGN KEY ("rev") REFERENCES "public"."revinfo" ("rev") ON UPDATE NO ACTION ON DELETE NO ACTION NOT DEFERRABLE INITIALLY IMMEDIATE;

如果想改表后綴的話洪规，可以通過org.hibernate.envers.audit_table_suffix的屬性進(jìn)行配置。里頭的rev字段表示revision的版本號(hào)循捺，一般全局遞增斩例。revtype字段表示操作類型，0表示新增从橘，1表示更新念赶，2表示刪除。

另外還有一個(gè)表是revinfo恰力，記錄每個(gè)變更的版本號(hào)和時(shí)間：

-- ----------------------------
--  Table structure for revinfo
-- ----------------------------
DROP TABLE IF EXISTS "public"."revinfo";
CREATE TABLE "public"."revinfo" (
    "rev" int4 NOT NULL,
    "revtstmp" int8
)
WITH (OIDS=FALSE);
ALTER TABLE "public"."revinfo" OWNER TO "postgres";

-- ----------------------------
--  Primary key structure for table revinfo
-- ----------------------------
ALTER TABLE "public"."revinfo" ADD PRIMARY KEY ("rev") NOT DEFERRABLE INITIALLY IMMEDIATE;

自定義revision entity

如果默認(rèn)的envers的實(shí)現(xiàn)不滿足你的要求的話叉谜，使用@RevisionEntity注解，替換@Audited踩萎，然后自定義listener停局，比如

@Entity
@RevisionEntity( ExampleListener.class )
public class ExampleRevEntity extends DefaultRevisionEntity {
    private String username;

    public String getUsername() { return username; }
    public void setUsername( String username ) { this.username = username; }
}
public class ExampleListener implements RevisionListener {

    public void newRevision( Object revisionEntity ) {
        ExampleRevEntity exampleRevEntity = ( ExampleRevEntity ) revisionEntity;
        Identity identity =
            (Identity) Component.getInstance( "org.jboss.seam.security.identity" );

        exampleRevEntity.setUsername( identity.getUsername() );
    }
}

具體的這里就不細(xì)講了，具體可以參考hibernate香府。

doc

• envers