Java 从RESTfulWebService返回对象列表时出错500
我试图从我的RESTfulWebService返回一个对象列表,但我一直收到一个错误500,内部服务器错误 服务器遇到内部错误,无法满足此请求 当我手动创建对象时,api的工作方式与预期的一样Java 从RESTfulWebService返回对象列表时出错500,java,web-services,rest,Java,Web Services,Rest,我试图从我的RESTfulWebService返回一个对象列表,但我一直收到一个错误500,内部服务器错误 服务器遇到内部错误,无法满足此请求 当我手动创建对象时,api的工作方式与预期的一样 @GET @Path("getAll") @Produces(MediaType.APPLICATION_XML) public List<Vak> getAllVakken() { List<Vak> vakken = new ArrayList<>();
@GET
@Path("getAll")
@Produces(MediaType.APPLICATION_XML)
public List<Vak> getAllVakken() {
List<Vak> vakken = new ArrayList<>();
Vak v = new Vak("vak1");
Vak v2 = new Vak("vak2");
vakken.add(v);
vakken.add(v2);
return vakken;
}
Test.java
@NamedQueries({
@NamedQuery(name = "Vak.getAll", query = "select v from Vak v")
})
@Entity
@XmlRootElement
public class Vak implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String naam;
@OneToMany(mappedBy = "vak")
private List<Test> testen = new ArrayList<>();
public Vak() {
}
public Vak(String naam) {
this.naam = naam;
}
@XmlElement
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
@XmlElement
public String getNaam() {
return naam;
}
public void setNaam(String naam) {
this.naam = naam;
}
@XmlElement
public List<Test> getTesten() {
return testen;
}
public void setTesten(List<Test> testen) {
this.testen = testen;
}
@Override
public int hashCode() {
int hash = 0;
hash += (id != null ? id.hashCode() : 0);
return hash;
}
@Override
public boolean equals(Object object) {
// TODO: Warning - this method won't work in the case the id fields are not set
if (!(object instanceof Vak)) {
return false;
}
Vak other = (Vak) object;
if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
return false;
}
return true;
}
@Override
public String toString() {
return "info.toegepaste.www.entity.Vak[ id=" + id + " ]";
}
}
@NamedQueries({
@NamedQuery(name = "Test.getAll", query = "select t from Test t order by t.vak")
})
@Entity
@XmlRootElement
public class Test implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private float behaaldCijfer, maxScore;
private String naam;
@Temporal(TemporalType.DATE)
private GregorianCalendar datum;
@ManyToOne
private Vak vak;
@ManyToOne
private Student student;
public Test() {
}
public Test(String naam, float behaaldCijfer, float maxScore, GregorianCalendar datum, Student student, Vak vak) {
this.maxScore = maxScore;
this.behaaldCijfer = behaaldCijfer;
this.naam = naam;
this.datum = datum;
this.vak = vak;
this.student = student;
}
@XmlElement
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
@XmlElement
public float getBehaaldCijfer() {
return behaaldCijfer;
}
public void setBehaaldCijfer(float behaaldCijfer) {
this.behaaldCijfer = behaaldCijfer;
}
@XmlElement
public float getMaxScore() {
return maxScore;
}
public void setMaxScore(float maxScore) {
this.maxScore = maxScore;
}
@XmlElement
public String getNaam() {
return naam;
}
public void setNaam(String naam) {
this.naam = naam;
}
@XmlElement
public GregorianCalendar getDatum() {
return datum;
}
public void setDatum(GregorianCalendar datum) {
this.datum = datum;
}
@XmlElement
public Vak getVak() {
return vak;
}
public void setVak(Vak vak) {
this.vak = vak;
}
@XmlElement
public Student getStudent() {
return student;
}
public void setStudent(Student student) {
this.student = student;
}
@Override
public int hashCode() {
int hash = 0;
hash += (id != null ? id.hashCode() : 0);
return hash;
}
@Override
public boolean equals(Object object) {
// TODO: Warning - this method won't work in the case the id fields are not set
if (!(object instanceof Test)) {
return false;
}
Test other = (Test) object;
if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
return false;
}
return true;
}
@Override
public String toString() {
return naam;
}
}
@Entity
@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Vak implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String naam;
@OneToMany(mappedBy = "vak", cascade = CascadeType.ALL)
@XmlElement
@XmlInverseReference(mappedBy = "vak")
private List<Test> testen = new ArrayList<>();
public Vak() {
}
public Vak(String naam) {
this.naam = naam;
}
//no @XmlElement here!
public String getNaam() {
return naam;
}
.....
}
@Entity
@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Test implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private float behaaldCijfer, maxScore;
private String naam;
@Temporal(TemporalType.DATE)
private GregorianCalendar datum;
@ManyToOne
@XmlElement
private Vak vak;
@ManyToOne
@XmlElement
private Student student;
public Test() {
}
.....
}
调用函数时,服务器客户端的输出窗口中没有任何错误。但是,当我从客户端调用函数时,我得到以下结果:
来自客户端的GlassFish输出:
Severe: javax.ws.rs.InternalServerErrorException: HTTP 500 Internal Server Error
at org.glassfish.jersey.client.JerseyInvocation.convertToException(JerseyInvocation.java:1020)
at org.glassfish.jersey.client.JerseyInvocation.translate(JerseyInvocation.java:877)
at org.glassfish.jersey.client.JerseyInvocation.access$800(JerseyInvocation.java:92)
at org.glassfish.jersey.client.JerseyInvocation$3.call(JerseyInvocation.java:722)
at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
at org.glassfish.jersey.internal.Errors.process(Errors.java:228)
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:444)
at org.glassfish.jersey.client.JerseyInvocation.invoke(JerseyInvocation.java:718)
at org.glassfish.jersey.client.JerseyInvocation$Builder.method(JerseyInvocation.java:430)
at org.glassfish.jersey.client.JerseyInvocation$Builder.get(JerseyInvocation.java:321)
at info.toegepaste.www.ManageServlet.getApiVak(ManageServlet.java:148)
at info.toegepaste.www.ManageServlet.processRequest(ManageServlet.java:126)
at info.toegepaste.www.ManageServlet.doPost(ManageServlet.java:179)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
at java.lang.Thread.run(Thread.java:745)
Warning: StandardWrapperValve[ManageServlet]: Servlet.service() for servlet ManageServlet threw exception
java.lang.NullPointerException
at info.toegepaste.www.ManageServlet.processRequest(ManageServlet.java:142)
at info.toegepaste.www.ManageServlet.doPost(ManageServlet.java:179)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
at java.lang.Thread.run(Thread.java:745)
任何帮助都将不胜感激
编辑
我想我找到了问题,但我不知道如何解决它
当我从类中删除任何相关对象时,API就会工作。
因此,我有一个类Vak
,它包含一个测试列表。如果我手动创建一个新列表,将Vak
的对象放入其中,而不引用Test
,则该列表有效
@GET
@Path("getAll")
@Produces(MediaType.APPLICATION_XML)
public List<Vak> getAllVakken() {
List<Vak> vakken1 = em.createNamedQuery("Vak.getAll").getResultList();
List<Vak> vakken2 = new ArrayList<>();
for (Vak vak : vakken1) {
Vak v = new Vak(vak.getNaam());
vakken2.add(v);
}
return vakken2;
}
所以问题一定出在这里。这是一个无限循环问题吗?Vak持有一份测试列表,其中每个测试持有一个Vak对象,每个Vak再次持有一份测试列表,等等。4天后终于找到了解决方案 有几个问题: 将以下依赖项添加到pom.xml:
<dependency>
<groupId>org.glassfish.jersey.media</groupId>
<artifactId>jersey-media-moxy</artifactId>
<version>2.19</version>
</dependency>
我错了。我从getter中删除了所有@XmlElement,并添加了@XmlAccessorType(XmlAccessType.FIELD)和@XmlInverseReference(mappedBy=“something”)
Vak.java
@NamedQueries({
@NamedQuery(name = "Vak.getAll", query = "select v from Vak v")
})
@Entity
@XmlRootElement
public class Vak implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String naam;
@OneToMany(mappedBy = "vak")
private List<Test> testen = new ArrayList<>();
public Vak() {
}
public Vak(String naam) {
this.naam = naam;
}
@XmlElement
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
@XmlElement
public String getNaam() {
return naam;
}
public void setNaam(String naam) {
this.naam = naam;
}
@XmlElement
public List<Test> getTesten() {
return testen;
}
public void setTesten(List<Test> testen) {
this.testen = testen;
}
@Override
public int hashCode() {
int hash = 0;
hash += (id != null ? id.hashCode() : 0);
return hash;
}
@Override
public boolean equals(Object object) {
// TODO: Warning - this method won't work in the case the id fields are not set
if (!(object instanceof Vak)) {
return false;
}
Vak other = (Vak) object;
if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
return false;
}
return true;
}
@Override
public String toString() {
return "info.toegepaste.www.entity.Vak[ id=" + id + " ]";
}
}
@NamedQueries({
@NamedQuery(name = "Test.getAll", query = "select t from Test t order by t.vak")
})
@Entity
@XmlRootElement
public class Test implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private float behaaldCijfer, maxScore;
private String naam;
@Temporal(TemporalType.DATE)
private GregorianCalendar datum;
@ManyToOne
private Vak vak;
@ManyToOne
private Student student;
public Test() {
}
public Test(String naam, float behaaldCijfer, float maxScore, GregorianCalendar datum, Student student, Vak vak) {
this.maxScore = maxScore;
this.behaaldCijfer = behaaldCijfer;
this.naam = naam;
this.datum = datum;
this.vak = vak;
this.student = student;
}
@XmlElement
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
@XmlElement
public float getBehaaldCijfer() {
return behaaldCijfer;
}
public void setBehaaldCijfer(float behaaldCijfer) {
this.behaaldCijfer = behaaldCijfer;
}
@XmlElement
public float getMaxScore() {
return maxScore;
}
public void setMaxScore(float maxScore) {
this.maxScore = maxScore;
}
@XmlElement
public String getNaam() {
return naam;
}
public void setNaam(String naam) {
this.naam = naam;
}
@XmlElement
public GregorianCalendar getDatum() {
return datum;
}
public void setDatum(GregorianCalendar datum) {
this.datum = datum;
}
@XmlElement
public Vak getVak() {
return vak;
}
public void setVak(Vak vak) {
this.vak = vak;
}
@XmlElement
public Student getStudent() {
return student;
}
public void setStudent(Student student) {
this.student = student;
}
@Override
public int hashCode() {
int hash = 0;
hash += (id != null ? id.hashCode() : 0);
return hash;
}
@Override
public boolean equals(Object object) {
// TODO: Warning - this method won't work in the case the id fields are not set
if (!(object instanceof Test)) {
return false;
}
Test other = (Test) object;
if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
return false;
}
return true;
}
@Override
public String toString() {
return naam;
}
}
@Entity
@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Vak implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String naam;
@OneToMany(mappedBy = "vak", cascade = CascadeType.ALL)
@XmlElement
@XmlInverseReference(mappedBy = "vak")
private List<Test> testen = new ArrayList<>();
public Vak() {
}
public Vak(String naam) {
this.naam = naam;
}
//no @XmlElement here!
public String getNaam() {
return naam;
}
.....
}
@Entity
@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Test implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private float behaaldCijfer, maxScore;
private String naam;
@Temporal(TemporalType.DATE)
private GregorianCalendar datum;
@ManyToOne
@XmlElement
private Vak vak;
@ManyToOne
@XmlElement
private Student student;
public Test() {
}
.....
}
在我修复代码后,GlassFish也有一个bug。我通过使用解决了这个问题。嗯,您是否查看了服务器日志文件以查看更多详细信息?我添加了GlassFish的日志文件。调用函数时不会出现任何错误。请花一些时间正确缩进代码。它确实有助于提高可读性。