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我试图从我的 restful web 服务返回一个对象列表,但我一直收到错误 500,内部服务器错误。
服务器遇到内部错误,无法完成此请求。
当我手动创建我的对象时,api 会像预期的那样工作。
@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;
}
当我将函数更改为以下时,它不再起作用。
@GET
@Path("getAll")
@Produces(MediaType.APPLICATION_XML)
public List<Vak> getAllVakken() {
List<Vak> vakken = em.createNamedQuery("Vak.getAll").getResultList();
return vakken;
}
调试函数时,List<Vak> vakken
被我的数据库中的对象填满,因此命名查询正在运行。但是当我转到下一行时 return vakken;
它跳转到 Method.java 第 498 行 return ma.invoke(obj, args);
.
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 + " ]";
}
}
测试.java
@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;
}
}
调用该函数时,我的服务器客户端的输出窗口中没有出现任何错误。但是当我从客户端调用该函数时,我得到了这个:
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)
如有任何帮助,我们将不胜感激!
编辑
我想我找到了问题,但我不知道如何解决。
当我从我的类中删除任何相关对象时,API 会起作用。所以我有我的课 Vak
其中包含测试列表。如果我手动创建一个新列表,我将 Vak
的对象放在其中在没有引用 Test
它有效。
@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;
}
上面的代码按照我的意愿以适当的 XML 布局返回我所有的 Vak 对象。
当我添加 v.setTesten(vak.getTesten());
行时我收到错误 500。
@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());
v.setTesten(vak.getTesten());
vakken2.add(vak);
}
return vakken2;
}
所以问题一定出在这里。是否存在无限循环问题? Vak 包含一个测试列表,其中每个 Test 包含一个 Vak 对象,其中每个 Vak 再次包含一个列表测试等..?
最佳答案
4天多后终于找到解决方案!
有几个问题:
将以下依赖项添加到您的 pom.xml 中:
<dependency>
<groupId>org.glassfish.jersey.media</groupId>
<artifactId>jersey-media-moxy</artifactId>
<version>2.19</version>
</dependency>
在您的根应用程序中添加 register(MoxyXmlFeature.class);
。
@ApplicationPath("rest")
public class MyApplication extends ResourceConfig {
public MyApplication() {
super(MultiPartFeature.class);
register(MoxyXmlFeature.class);
packages("info.toegepaste.www.ejb");
packages("info.toegepaste.www.entity");
}
}
我的实体错了。我从 setter/getter 中删除了所有@XmlElement 并添加了@XmlAccessorType(XmlAccessType.FIELD) 和@XmlInverseReference(mappedBy="something")
Vak.java
@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;
}
.....
}
测试.java
@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() {
}
.....
}
在我修复我的代码后,GlassFish 也有一个错误。 Have a look here.我使用 Payara 解决了这个问题.
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