Question

无法弄清楚如何从我的数据库中检索'blob'类型。无法弄清楚如何在JPA中做。

public interface ActeRepository extends JpaRepository<byte[], String> {
    @Query(value = "select doc from t_doc_content", nativeQuery = true)
    public List<byte[]> findActeByBordereau(String id);
}

错误：

引起：java.lang.IllegalArgumentException：不是托管类型：class [B. 在org.hibernate.jpa.internal.metamodel.MetamodelImpl.managedType（MetamodelImpl.java:219）在org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation。（JpaMetamodelEntityInformation.java:68）在org.springframework.data.jpa.repository.support.JpaEntityInformationSupport.getEntityInformation（JpaEntityInformationSupport.java:67）在org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getEntityInformation（JpaRepositoryFactory.java:152）在org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository（JpaRepositoryFactory.java:99）在org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository（JpaRepositoryFactory.java:81）在org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository（RepositoryFactorySupport.java:185）在org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.initAndReturn（RepositoryFactoryBeanSupport.java:251）在org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet（RepositoryFactoryBeanSupport.java:237） at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet（JpaRepositoryFactoryBean.java:92）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods（AbstractAutowireCapableBeanFactory.java:1637）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean（AbstractAutowireCapableBeanFactory.java:1574） ...省略了29个常见帧

有什么想法吗？

Answer 1

您的界面定义不正确

也许改为

private WebView wv;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    wv = (WebView) findViewById(R.id.webview1);
    wv.loadUrl("https://www.xxxxx.com.br");
    wv.setWebViewClient(new WebViewClient());

    WebSettings ws = wv.getSettings();
    ws.setJavaScriptEnabled(true);
    ws.setSupportZoom(false);

}

主键是否为String，如果是，则上述情况正常，否则将public interface ActeRepository extends JpaRepository< Acte, String> {更改为它。好久不过？

Answer 2

这不是JpaRepository的工作方式，在扩展时，您需要记住它的类型为JpaRepository<T, ID extends Serializable>，其中T是您在其中映射为表格的POJO数据库可能使用@Entity而ID是您表的主键Long或Integer，我怀疑你有一个String作为主键，因为整数更快到指数。我不知道你的其余代码，但是给你一个例子：

@Entity
public class File {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;

@Lob
private byte[] bytes;

@ManyToOne
@JoinColumn(name = "user_id")
private User user;

public File() {
}

public File(String name, byte[] bytes, User user) {
    this.name = name;
    this.bytes = bytes;
    this.user = user;
}

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 byte[] getBytes() {
    return bytes;
}

public void setBytes(byte[] bytes) {
    this.bytes = bytes;
}

public User getUser() {
    return user;
}

public void setUser(User user) {
    this.user = user;
}
}

@Repository
public interface FileRepository extends JpaRepository<File, Long>{

List<File> findByName(String name);
}

在获得对象列表后，您将从每个对象获取该字节变量。

@Query JPA返回blob

2 个答案: