rest - 使用 Jersey 的 JAX WS RS - 返回集合、地图等

Question

我正在使用泽西 2.3

我的 WS 端点类：

@Path("/employees")
public class EmployeeWSEndpoint {

    @Context
    Request request;

    @GET
    @Path("/allEmployees")
    @Produces(MediaType.APPLICATION_JSON)
    public List<Employee> getAllEmployees() {

        System.out.println("In EmployeeWSEndpoint.getAllEmployees()");

        EmployeeService employeeService = new EmployeeServiceImpl();
        return employeeService.getAllEmployees();
    }

    @GET
    @Path("/allDept")
    @Produces(MediaType.APPLICATION_JSON)
    public List<String> getAllDept() {

        System.out.println("In EmployeeWSEndpoint.getAllDept()");

        List<String> deptNames = new ArrayList<>();
        deptNames.add("CoE");
        deptNames.add("iLabs");

        return deptNames;
    }

    @GET
    @Path("/allDeptPOJO")
    @Produces(MediaType.APPLICATION_JSON)
    public TempPOJO getAllDeptPOJO() {

        System.out.println("In EmployeeWSEndpoint.getAllDeptPOJO");

        TempPOJO tempPOJO = new TempPOJO();

        return tempPOJO;
    }
}

员工 POJO：

public class Employee {

    private int id;
    private String firstName;
    private String middleName;
    private String lastName;
    private Date dob;
    private int deptId;

    public Employee() {

    }

    public Employee(String firstName, String middleName, String lastName,
            Date dob, int deptId) {
        this.firstName = firstName;
        this.middleName = middleName;
        this.lastName = lastName;
        this.dob = dob;
        this.deptId = deptId;
    }

    public Employee(int id, String firstName, String middleName,
            String lastName, Date dob, int deptId) {
        this.id = id;
        this.firstName = firstName;
        this.middleName = middleName;
        this.lastName = lastName;
        this.dob = dob;
        this.deptId = deptId;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getMiddleName() {
        return middleName;
    }

    public void setMiddleName(String middleName) {
        this.middleName = middleName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public Date getDob() {
        return dob;
    }

    public void setDob(Date dob) {
        this.dob = dob;
    }

    public int getDeptId() {
        return deptId;
    }

    public void setDeptId(int deptId) {
        this.deptId = deptId;
    }

    @Override
    public String toString() {
        return firstName + " " + middleName + " " + " " + lastName;
    }
}

一个临时 POJO ：

public class TempPOJO {

    private List<String> deptNames;

    public List<String> getDeptNames() {

        deptNames = new ArrayList<>();
        deptNames.add("CoE");
        deptNames.add("iLabs");

        return deptNames;
    }

    public void setDeptNames(List<String> deptNames) {
        this.deptNames = deptNames;
    }

}

列出不同方法的输出：

所有的员工

[{"deptId":1,"dob":"1978-06-19","firstName":"Garfield","id":0,"lastName":"Arbuckle","middleName":"John"},{"deptId":1,"dob":"1946-07-07","firstName":"John","id":0,"lastName":"Rambo","middleName":"R"}]

/所有部门

In EmployeeWSEndpoint.getAllDept()
Oct 01, 2013 3:31:08 PM org.glassfish.jersey.server.ServerRuntime$Responder mapException
WARNING: WebApplicationException cause:
javax.xml.bind.MarshalException
 - with linked exception:
[Exception [EclipseLink-25003] (Eclipse Persistence Services - 2.5.0.v20130507-3faac2b): org.eclipse.persistence.exceptions.XMLMarshalException
Exception Description: An error occurred marshalling the object
Internal Exception: Exception [EclipseLink-25007] (Eclipse Persistence Services - 2.5.0.v20130507-3faac2b): org.eclipse.persistence.exceptions.XMLMarshalException
Exception Description: A descriptor for class java.lang.String was not found in the project.  For JAXB, if the JAXBContext was bootstrapped using TypeMappingInfo[] you must call a marshal method that accepts TypeMappingInfo as an input parameter.]
    at org.eclipse.persistence.jaxb.JAXBMarshaller.marshal(JAXBMarshaller.java:403)
    at org.eclipse.persistence.jaxb.rs.MOXyJsonProvider.writeTo(MOXyJsonProvider.java:808)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.invokeWriteTo(WriterInterceptorExecutor.java:243)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:230)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:149)
    at org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor.aroundWriteTo(JsonWithPaddingInterceptor.java:103)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:149)
    at org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundWriteTo(MappableExceptionWrapperInterceptor.java:88)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:149)
    at org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1139)
    at org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:562)
    at org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:357)
    at org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:347)
    at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:258)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:267)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:318)
    at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:235)
    at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:983)
    at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:359)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:372)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:335)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:218)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:947)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1009)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: Exception [EclipseLink-25003] (Eclipse Persistence Services - 2.5.0.v20130507-3faac2b): org.eclipse.persistence.exceptions.XMLMarshalException
Exception Description: An error occurred marshalling the object
Internal Exception: Exception [EclipseLink-25007] (Eclipse Persistence Services - 2.5.0.v20130507-3faac2b): org.eclipse.persistence.exceptions.XMLMarshalException
Exception Description: A descriptor for class java.lang.String was not found in the project.  For JAXB, if the JAXBContext was bootstrapped using TypeMappingInfo[] you must call a marshal method that accepts TypeMappingInfo as an input parameter.
    at org.eclipse.persistence.exceptions.XMLMarshalException.marshalException(XMLMarshalException.java:97)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:911)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:848)
    at org.eclipse.persistence.jaxb.JAXBMarshaller.marshal(JAXBMarshaller.java:401)
    ... 41 more
Caused by: Exception [EclipseLink-25007] (Eclipse Persistence Services - 2.5.0.v20130507-3faac2b): org.eclipse.persistence.exceptions.XMLMarshalException
Exception Description: A descriptor for class java.lang.String was not found in the project.  For JAXB, if the JAXBContext was bootstrapped using TypeMappingInfo[] you must call a marshal method that accepts TypeMappingInfo as an input parameter.
    at org.eclipse.persistence.exceptions.XMLMarshalException.descriptorNotFoundInProject(XMLMarshalException.java:139)
    at org.eclipse.persistence.internal.oxm.Context$ContextState.getSession(Context.java:143)
    at org.eclipse.persistence.oxm.XMLContext$XMLContextState.getSession(XMLContext.java:787)
    at org.eclipse.persistence.oxm.XMLContext$XMLContextState.getSession(XMLContext.java:1)
    at org.eclipse.persistence.internal.oxm.Context.getSession(Context.java:451)
    at org.eclipse.persistence.oxm.XMLContext.getSession(XMLContext.java:356)
    at org.eclipse.persistence.oxm.XMLContext.getSession(XMLContext.java:1)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:568)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:1096)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:869)
    ... 43 more

/allDeptPOJO

{"deptNames":["CoE","iLabs"]}

我有一些疑问：

我想从 Jersey 2.3 开始，注释 'XmlRootElement' 对于 POJO 来说不是必需的——我还没有这样做，但是调用工作。请确认
如果是 pojo(Employee) 的 List 或具有 List 的 pojo，响应是正确的，但对于 List、Map 等，它会失败（基本上，对于 Java 类型） - 为什么会这样？如果它适用于 Employee，为什么它不适用于 Java 类型？是否需要编写 XmlAdapter？

注意：在大多数情况下，我想要 JSON 格式的响应。

修改 web.xml 以使用 Jackson ：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="WebApp_ID" version="3.0">
    <display-name>Jersey</display-name>
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
    </welcome-file-list>

    <servlet>
        <servlet-name>Jersey REST Service</servlet-name>
        <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
        <init-param>
            <param-name>jersey.config.server.provider.packages</param-name>
            <param-value>com.ws.jaxrs.jersey</param-value>
        </init-param>
        <init-param>
            <param-name>jersey.config.disableMoxyJson.server</param-name>
            <param-value>true</param-value>
        </init-param>

        <init-param>
            <param-name>jersey.config.server.provider.packages</param-name>
            <param-value>com.ws.jaxrs.jersey;org.codehaus.jackson.jaxrs</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>Jersey REST Service</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>


</web-app>

我得到以下异常：

In EmployeeWSEndpoint.getAllDept()
Nov 07, 2013 10:04:12 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Jersey REST Service] in context with path [/Jersey] threw exception [org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyWriter not found for media type=application/json, type=class java.util.ArrayList, genericType=java.util.List<java.lang.String>.] with root cause
org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyWriter not found for media type=application/json, type=class java.util.ArrayList, genericType=java.util.List<java.lang.String>.
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:227)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:149)
    at org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor.aroundWriteTo(JsonWithPaddingInterceptor.java:103)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:149)
    at org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundWriteTo(MappableExceptionWrapperInterceptor.java:88)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:149)
    at org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1139)
    at org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:562)
    at org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:357)
    at org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:347)
    at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:258)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:267)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:318)
    at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:235)
    at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:983)
    at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:359)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:372)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:335)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:218)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:964)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

score 17 · Accepted Answer

杰克逊是目前对我来说最好的解决方案。

要将 Jackson 用作 JSON 提供程序，您需要将jersey-media-json-jackson模块添加到pom.xml文件中：

<dependency>
    <groupId>org.glassfish.jersey.media</groupId>
    <artifactId>jersey-media-json-jackson</artifactId>
    <version>2.7</version>
</dependency>

注意：自动发现功能不起作用。

启用 Jackson JSON 功能的构建客户端：

final Client client = ClientBuilder.newBuilder()
                    .register(JacksonFeature.class)
                    .build();

创建启用了 Jackson JSON 功能的 JAX-RS 服务器应用程序：

final Application application = new ResourceConfig()
                              .packages("my.rest.package")
                              .register(JacksonFeature.class);

另请查看官方Jersey json-jackson 示例。

score 7 · Accepted Answer

使用不同的 JSON 提供程序

我不知道为什么 jersey startet 采用 MOXy 作为他们的默认 JSON 提供程序，但这显然是个坏主意。

您（和我 - 以及其他人）遇到的问题是 MOXy无法映射简单 Java 类型（如字符串）的集合的结果 - 这只是荒谬的恕我直言。其他提供商（如jackson）没有这个问题，所以切换肯定会有所帮助。

这是我所做的：

告诉泽西不要使用 MOXy。将此添加到您的 web.xml：

<init-param>
    <param-name>jersey.config.disableMoxyJson.server</param-name>
    <param-value>true</param-value>
</init-param>

将杰克逊添加到您的 pom 中。这样的事情会做：

<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-jaxrs</artifactId>
    <version>1.9.12</version>
</dependency>

告诉 jersey 扫描 jackson jackson 包裹。它将找到（并使用）jackson 提供的 json 提供程序：

<init-param>
    <param-name>jersey.config.server.provider.packages</param-name>
    <param-value>com.example.your.package;org.codehaus.jackson.jaxrs</param-value>
</init-param>

score 6 · Accepted Answer

注意：我是EclipseLink JAXB (MOXy)负责人，也是JAXB (JSR-222)专家组的成员。

您遇到的异常是由于 MOXy 的MOXyJsonProvider. MOXyJsonProvider是 JAX-RS 接口MessageBodyReader/的实现MessageBodyWriter。我已将返回 false 的isWriteable方法更改为List<String>返回 false，以便另一个提供程序可以处理它。

我还打开了以下增强请求以将此支持添加到 MOXy：

http://bugs.eclipse.org/417725

score 2 · Accepted Answer

您可以使用 RestEasy 作为 JAX-RS 实现

GlassFish4 使用 Jersey/MOXy 作为 JAX-RS 的实现。他们在将简单 Java 类型（如字符串）的集合映射到 JSON 时遇到问题 - https://bugs.eclipse.org/bugs/show_bug.cgi?id=417723

WildFly 和 JBoss 使用 RestEasy/Jackson 作为 JAX-RS 的实现，映射没有问题。

您可以在任何 Java 应用程序服务器中使用 RestEasy 代替 Jersey，例如 WildFly (JBoss)、GlassFish 或 Tomcat，

只需更换：

    <dependency>
        <groupId>javax</groupId>
        <artifactId>javaee-api</artifactId>
        <version>7.0</version>
        <scope>provided</scope>
    </dependency>

和：

    <dependency>
        <groupId>org.jboss.resteasy</groupId>
        <artifactId>resteasy-servlet-initializer</artifactId>
        <version>3.0.7.Final</version>
        <scope>compile</scope>
    </dependency>        
    <dependency>
       <groupId>org.jboss.resteasy</groupId>
       <artifactId>resteasy-jaxrs</artifactId>
       <version>3.0.7.Final</version>
        <scope>compile</scope>
    </dependency>
    <dependency>
        <groupId>org.jboss.resteasy</groupId>
        <artifactId>resteasy-jackson-provider</artifactId>
        <version>3.0.7.Final</version>
        <scope>compile</scope>
    </dependency>
    <dependency>
        <groupId>org.jboss.resteasy</groupId>
        <artifactId>resteasy-jaxb-provider</artifactId>
        <version>3.0.7.Final</version>
        <scope>compile</scope>
    </dependency>

它对我有用。

来自波兰卢布林的问候:)

score 0 · Accepted Answer

我在返回一个List<String>对象时遇到了同样的问题。我把它包在一个RestStringList班级里，这很有效。如果我们有更多这些事情要做，我可能会转向杰克逊。

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class RestStringList implements Serializable {
    private static final long serialVersionUID = 1L;

    private List<String> stringList = null;

    public RestStringList() {
        this.stringList = new ArrayList<String>();
    }

    public void setStringList(List<String> stringList) {
        this.stringList = new ArrayList<String>(stringList);
    }

    public List<String> getStringList() {
        return stringList;
    }

    public String toString() {
        return "{ strings=" + stringList + " }";
    }
}

rest - 使用 Jersey 的 JAX WS RS - 返回集合、地图等

5 回答 5

启用 Jackson JSON 功能的构建客户端：

创建启用了 Jackson JSON 功能的 JAX-RS 服务器应用程序：

使用不同的 JSON 提供程序

Related

Reference