我正在用 Java 开发一个程序，我正在使用 Jackson 输出 XML 和 JSON。目前，当我以 XML 输出而不是 JSON 输出时出现错误。
错误是以下错误消息
我试图输出的类是这个，里面有一个这个实例作为数据。当我请求 JSON 时，我有这个输出......
Error Message
Jan 27, 2013 12:02:55 AM com.sun.jersey.spi.container.ContainerResponse logException
SEVERE: Mapped exception to response: 500 (Internal Server Error)
javax.ws.rs.WebApplicationException: javax.xml.bind.MarshalException
- with linked exception:
[com.sun.istack.internal.SAXException2: class pt.eoliveira.appmanager.dao.Users nor any of its super class is known to this context.
javax.xml.bind.JAXBException: class pt.eoliveira.appmanager.dao.Users nor any of its super class is known to this context.]
at com.sun.jersey.core.provider.jaxb.AbstractRootElementProvider.writeTo(AbstractRootElementProvider.java:159)
at com.sun.jersey.spi.container.ContainerResponse.write(ContainerResponse.java:306)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1448)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1360)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1350)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:538)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:716)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1002)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
Caused by: javax.xml.bind.MarshalException
- with linked exception:
[com.sun.istack.internal.SAXException2: class pt.eoliveira.appmanager.dao.Users nor any of its super class is known to this context.
javax.xml.bind.JAXBException: class pt.eoliveira.appmanager.dao.Users nor any of its super class is known to this context.]
at com.sun.xml.internal.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:311)
at com.sun.xml.internal.bind.v2.runtime.MarshallerImpl.marshal(MarshallerImpl.java:236)
at javax.xml.bind.helpers.AbstractMarshallerImpl.marshal(AbstractMarshallerImpl.java:95)
at com.sun.jersey.core.provider.jaxb.AbstractRootElementProvider.writeTo(AbstractRootElementProvider.java:179)
at com.sun.jersey.core.provider.jaxb.AbstractRootElementProvider.writeTo(AbstractRootElementProvider.java:157)
... 27 more
Caused by: com.sun.istack.internal.SAXException2: class pt.eoliveira.appmanager.dao.Users nor any of its super class is known to this context.
javax.xml.bind.JAXBException: class pt.eoliveira.appmanager.dao.Users nor any of its super class is known to this context.
at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.reportError(XMLSerializer.java:235)
at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.reportError(XMLSerializer.java:250)
at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:642)
at com.sun.xml.internal.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:143)
at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:343)
at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsSoleContent(XMLSerializer.java:582)
at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeRoot(ClassBeanInfoImpl.java:325)
at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsRoot(XMLSerializer.java:483)
at com.sun.xml.internal.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:308)
... 31 more
Caused by: javax.xml.bind.JAXBException: class pt.eoliveira.appmanager.dao.Users nor any of its super class is known to this context.
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.getBeanInfo(JAXBContextImpl.java:573)
at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:637)
... 37 more
消息包装器
package pt.eoliveira.appmanager.wrappers;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement(name = "message")
public class Message {
private int error = 0;
private String errorMessage = "";
private Object data;
public Message() {
}
public Message(int error, String errorMessage) {
this.error = error;
this.errorMessage = errorMessage;
}
public Message(Object data) {
this.data = data;
}
public Message setData(Object data) {
this.data = data;
return this;
}
public Message setError(int error, String errorMessage) {
this.error = error;
this.errorMessage = errorMessage;
return this;
}
public int getError() {
return error;
}
public String getErroMessage() {
return errorMessage;
}
public Object getData() {
return data;
}
}
进入数据对象的类
package pt.eoliveira.appmanager.dao;
import java.io.Serializable;
import java.security.NoSuchAlgorithmException;
import java.util.Collection;
import javax.persistence.Basic;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.OneToOne;
import javax.persistence.Table;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;
import org.codehaus.jackson.annotate.JsonIgnore;
import pt.eoliveira.appmanager.utils.MySqlTools;
@Entity
@Table(name = "users")
@XmlRootElement
@NamedQueries({
@NamedQuery(name = "Users.findAll", query = "SELECT u FROM Users u"),
@NamedQuery(name = "Users.findByUserId", query = "SELECT u FROM Users u WHERE u.userId = :userId"),
@NamedQuery(name = "Users.findByUsername", query = "SELECT u FROM Users u WHERE u.username = :username"),
@NamedQuery(name = "Users.findByPassword", query = "SELECT u FROM Users u WHERE u.password = :password"),
@NamedQuery(name = "Users.findByEmail", query = "SELECT u FROM Users u WHERE u.email = :email"),
@NamedQuery(name = "Users.findByPermissions", query = "SELECT u FROM Users u WHERE u.permissions = :permissions")
})
public class Users implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "user_id")
private Integer userId;
@Basic(optional = false)
@Column(name = "username")
private String username;
@Basic(optional = false)
@Column(name = "password")
@XmlTransient
@JsonIgnore
private String password;
@Basic(optional = false)
@Column(name = "email")
private String email;
@Basic(optional = false)
@Column(name = "permissions")
private int permissions;
@OneToOne(mappedBy = "owner")
private Sessions sessions;
@JoinColumn(name = "country", referencedColumnName = "country_id")
@ManyToOne(optional = false)
private Country country;
@OneToMany(cascade = CascadeType.ALL, mappedBy = "owner")
private Collection<Apps> appsCollection;
public Users() {
}
public Users(String username) {
this.username = username;
}
public Users(Integer userId) {
this.userId = userId;
}
public Users(Integer userId, String username, String password, String email, int permissions) {
this.userId = userId;
this.username = username;
this.password = password;
this.email = email;
this.permissions = permissions;
}
public Integer getUserId() {
return userId;
}
public void setUserId(Integer userId) {
this.userId = userId;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public int getPermissions() {
return permissions;
}
public void setPermissions(int permissions) {
this.permissions = permissions;
}
public Sessions getSessions() {
return sessions;
}
public void setSessions(Sessions sessions) {
this.sessions = sessions;
}
public Country getCountry() {
return country;
}
public void setCountry(Country country) {
this.country = country;
}
@XmlTransient
public Collection<Apps> getAppsCollection() {
return appsCollection;
}
public void setAppsCollection(Collection<Apps> appsCollection) {
this.appsCollection = appsCollection;
}
public boolean isValid(String password) {
try {
return this.password.equals(MySqlTools.MD5Encode(password));
} catch (NoSuchAlgorithmException ex) {
ex.printStackTrace();
}
return false;
}
@Override
public int hashCode() {
int hash = 0;
hash += (userId != null ? userId.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 Users)) {
return false;
}
Users other = (Users) object;
if ((this.userId == null && other.userId != null) || (this.userId != null && !this.userId.equals(other.userId))) {
return false;
}
return true;
}
@Override
public String toString() {
return "Users{" + "userId=" + userId + ", username=" + username + ", password=" + password + ", email=" + email + ", permissions=" + permissions + ", sessions=" + sessions + ", country=" + country + ", appsCollection=" + appsCollection + '}';
}
}
示例 Json 输出
{"error":0,"data":
{"userId":17,"username":"xxxx","password":"xxxx","email":"xxxx","permissions":1,"sessions":
{"sessionId":8,"sessionKey":"b0880029fae3b4588c37640f8452b2da","creationStamp":2017052136},"country":{"countryId":177,"iso2":"PT","shortName":"Portugal","longName":"Portuguese Republic","iso3":"PRT","numcode":"620","unMember":"yes","callingCode":"351","cctld":".pt"}},
"erroMessage":""}
我生成输出的方法是
@GET
@Path("validate")
@Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
public Message validate(@QueryParam("username") String username, @QueryParam("password") String password) throws NoSuchAlgorithmException {
Users rtn = validateUser(username, password);
if (rtn != null) {
if (rtn.getSessions() == null) {
rtn.setSessions(new Sessions(MySqlTools.MD5Encode(System.currentTimeMillis() + MySqlTools.SALT), (int) System.currentTimeMillis(), rtn));
super.edit(rtn);
}
return new Message(rtn);
}
return new Message(1,"Invalid Username or Password");
}
对我来说，奇怪的是为什么它只在尝试将输出作为 XML 时给出错误？...