Java NullPointerException正在尝试检索@manytone父字段-Spring启动
我试图从@ManyToOne关系中的父实体获取一个字段,但在集成测试期间抛出一个NullPointerException。当我尝试打印父字段时,下面是包括测试在内的两个实体的代码 唱片集实体-父级Java NullPointerException正在尝试检索@manytone父字段-Spring启动,java,hibernate,spring-boot,jpa,Java,Hibernate,Spring Boot,Jpa,我试图从@ManyToOne关系中的父实体获取一个字段,但在集成测试期间抛出一个NullPointerException。当我尝试打印父字段时,下面是包括测试在内的两个实体的代码 唱片集实体-父级 import java.time.LocalDate; import java.util.ArrayList; import java.util.List; import javax.persistence.CascadeType; import javax.persistence.Column;
import java.time.LocalDate;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.validation.constraints.NotBlank;
import org.hibernate.annotations.GenericGenerator;
@Entity
@Table(name = "albuns")
public class Album {
@Id
@GeneratedValue(strategy = GenerationType.AUTO, generator = "native")
@GenericGenerator(name = "native", strategy = "native")
private Long codigo;
@NotBlank(message = "Erro: Certifique-se de digitar o nome do album.")
@Column(nullable = false)
private String nome;
@OneToMany(mappedBy = "album", cascade = { CascadeType.PERSIST, CascadeType.REMOVE }, fetch = FetchType.EAGER)
private List<Imagem> imagens = new ArrayList<>();
@Column(name = "data_criacao", nullable = false)
private LocalDate dataCriacao;
@Column(unique = true, nullable = false)
private String capa;
protected Album() {
}
public Album(String nome, LocalDate dataCriacao, String capa) {
this.nome = nome;
this.dataCriacao = dataCriacao;
this.capa = capa;
}
public Long getCodigo() {
return codigo;
}
public void setCodigo(Long codigo) {
this.codigo = codigo;
}
public String getNome() {
return nome;
}
public void setNome(String nome) {
this.nome = nome;
}
public LocalDate getDataCriacao() {
return dataCriacao;
}
public void setDataCriacao(LocalDate dataCriacao) {
this.dataCriacao = dataCriacao;
}
public String getCapa() {
return capa;
}
public void setCapa(String capa) {
this.capa = capa;
}
public List<Imagem> getImagens() {
return imagens;
}
public void setImagens(List<Imagem> imagens) {
this.imagens = imagens;
}
}
import static org.assertj.core.api.Assertions.assertThat;
import java.time.LocalDate;
import java.util.ArrayList;
import java.util.List;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
import org.springframework.boot.test.autoconfigure.orm.jpa.TestEntityManager;
import org.springframework.test.context.junit4.SpringRunner;
import com.servidor.multiplatform.entidades.Album;
import com.servidor.multiplatform.entidades.Imagem;
import com.servidor.multiplatform.repositorios.AlbumRepositorio;
@RunWith(SpringRunner.class)
@DataJpaTest
public class TesteDeIntegracaoAlbumRepositorio {
@Autowired
private TestEntityManager entityManager;
@Autowired
private AlbumRepositorio albumRepositorio;
@Test
public void TesteDeInsercaoDoAlbumAsSuasImagensEPesquisaDaSuaInformacao() {
// Album
Album album1 = new Album("Album 1", LocalDate.now(), "Capa 1");
// List for Test
List<Imagem> imagensLocal = new ArrayList<>();
// Filling the Lists with new images
for (int i = 0; i < 4; i++) {
Imagem imagem = new Imagem("url" + i, LocalDate.now());
imagensLocal.add(imagem);
album1.getImagens().add(imagem);
}
// Persisting the Album and the Pictures
entityManager.persist(album1);
entityManager.flush();
// Getting the Album and the Pictures
Album albumEncontrado = albumRepositorio.findByNome("Album 1");
List<Imagem> imagensPesistidas = albumEncontrado.getImagens();
Album album = entityManager.find(Album.class, 1L);
System.out.println(album.getCodigo());
for (Imagem imagem : album.getImagens()) {
// The problem is here in this code
System.out.println(imagem.getAlbumCodigo());
}
// Testing the Album
assertThat(album1.getNome()).isEqualTo(albumEncontrado.getNome());
// Testing the Lists
Assert.assertEquals(imagensLocal, imagensPesistidas);
}
}
唱片库
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import com.servidor.multiplatform.entidades.Album;
@Repository
public interface AlbumRepositorio extends JpaRepository<Album, Long> {
public Album findByNome(String nome);
}
Imagem.album
保持为空,因为单元测试中给出的代码从未写入该字段。仅通过album1.getImagens().add(imagem)
设置关系的一侧
NullPointerException
也可以通过在查询数据库之前通过清除持久性上下文来避免。这将打破列表相等的断言,因为它取决于列表中元素的标识。原因是Imagem
没有实现equals
。即使在添加了equals
之后,它仍然假设元素的顺序不是那么确定的。您的数据库中是否有特定相册实体的列表。?您的解决方案有效,谢谢,实体映射良好,问题是没有将相册实例分配给图像对象
import static org.assertj.core.api.Assertions.assertThat;
import java.time.LocalDate;
import java.util.ArrayList;
import java.util.List;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
import org.springframework.boot.test.autoconfigure.orm.jpa.TestEntityManager;
import org.springframework.test.context.junit4.SpringRunner;
import com.servidor.multiplatform.entidades.Album;
import com.servidor.multiplatform.entidades.Imagem;
import com.servidor.multiplatform.repositorios.AlbumRepositorio;
@RunWith(SpringRunner.class)
@DataJpaTest
public class TesteDeIntegracaoAlbumRepositorio {
@Autowired
private TestEntityManager entityManager;
@Autowired
private AlbumRepositorio albumRepositorio;
@Test
public void TesteDeInsercaoDoAlbumAsSuasImagensEPesquisaDaSuaInformacao() {
// Album
Album album1 = new Album("Album 1", LocalDate.now(), "Capa 1");
// List for Test
List<Imagem> imagensLocal = new ArrayList<>();
// Filling the Lists with new images
for (int i = 0; i < 4; i++) {
Imagem imagem = new Imagem("url" + i, LocalDate.now());
imagensLocal.add(imagem);
album1.getImagens().add(imagem);
}
// Persisting the Album and the Pictures
entityManager.persist(album1);
entityManager.flush();
// Getting the Album and the Pictures
Album albumEncontrado = albumRepositorio.findByNome("Album 1");
List<Imagem> imagensPesistidas = albumEncontrado.getImagens();
Album album = entityManager.find(Album.class, 1L);
System.out.println(album.getCodigo());
for (Imagem imagem : album.getImagens()) {
// The problem is here in this code
System.out.println(imagem.getAlbumCodigo());
}
// Testing the Album
assertThat(album1.getNome()).isEqualTo(albumEncontrado.getNome());
// Testing the Lists
Assert.assertEquals(imagensLocal, imagensPesistidas);
}
}
TesteDeIntegracaoAlbumRepositorio.TesteDeInsercaoDoAlbumAsSuasImagensEPesquisaDaSuaInformacao
com.servidor.multiplatform.TesteDeIntegracaoAlbumRepositorio
TesteDeInsercaoDoAlbumAsSuasImagensEPesquisaDaSuaInformacao(com.servidor.multiplatform.TesteDeIntegracaoAlbumRepositorio)
java.lang.NullPointerException
at com.servidor.multiplatform.entidades.Imagem.getAlbumCodigo(Imagem.java:75)
at com.servidor.multiplatform.TesteDeIntegracaoAlbumRepositorio.TesteDeInsercaoDoAlbumAsSuasImagensEPesquisaDaSuaInformacao(TesteDeIntegracaoAlbumRepositorio.java:64)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:74)
at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:84)
at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at org.junit.vintage.engine.execution.RunnerExecutor.execute(RunnerExecutor.java:40)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(Unknown Source)
at java.util.stream.ReferencePipeline$3$1.accept(Unknown Source)
at java.util.Iterator.forEachRemaining(Unknown Source)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Unknown Source)
at java.util.stream.AbstractPipeline.copyInto(Unknown Source)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(Unknown Source)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(Unknown Source)
at java.util.stream.AbstractPipeline.evaluate(Unknown Source)
at java.util.stream.ReferencePipeline.forEach(Unknown Source)
at org.junit.vintage.engine.VintageTestEngine.executeAllChildren(VintageTestEngine.java:80)
at org.junit.vintage.engine.VintageTestEngine.execute(VintageTestEngine.java:71)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:229)
at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:197)
at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:211)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:191)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:137)
at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:89)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
//Imagem.album is not set in this loop:
for (int i = 0; i < 4; i++) {
Imagem imagem = new Imagem("url" + i, LocalDate.now());
imagensLocal.add(imagem);
album1.getImagens().add(imagem);
}
for (int i = 0; i < 4; i++) {
Imagem imagem = new Imagem("url" + i, LocalDate.now());
imagensLocal.add(imagem);
album1.getImagens().add(imagem);
imagem.setAlbum(album1);
}