ReST Webservices：如何接受参数列表

Question

我有 rest 方法，它应该接受一个对象列表。 我试过这个：

@GET     
@Path("/getList")     
@Produces(MediaType.APPLICATION_JSON)    
public response getList(@BeanParam List<MyObjects> myobjectsList) {          
//Iterate over the list and return        
return Response.ok(outputList).build();     
}

假设 MyObjects 有一个属性：

public class MyObjects {
   @QueryParam       
   private String name;

   public String getName() {    
       return name;    
   }
}

所以当进行休息调用时：localhost/restservice/getList?name=A&name=B 我得到以下异常：

Message:A MultiException has 2 exceptions.  They are:
1. java.lang.NoSuchMethodException: Could not find a suitable constructor in java.util.List class.
2. java.lang.IllegalArgumentException: Errors were discovered while reifying SystemDescriptor(
    implementation=java.util.List
    contracts={java.util.List}
    scope=org.glassfish.jersey.process.internal.RequestScoped
    qualifiers={}
    descriptorType=CLASS
    descriptorVisibility=NORMAL
    metadata=
    rank=0
    loader=null
    proxiable=null
    proxyForSameScope=null
    analysisName=null
    id=349
    locatorId=0
    identityHashCode=1585683969
    reified=false)
MultiException stack 1 of 2
java.lang.NoSuchMethodException: Could not find a suitable constructor in java.util.List class.
    at org.glassfish.jersey.internal.inject.JerseyClassAnalyzer.getConstructor(JerseyClassAnalyzer.java:192)
    at org.jvnet.hk2.internal.Utilities.getConstructor(Utilities.java:180)
    at org.jvnet.hk2.internal.ClazzCreator.initialize(ClazzCreator.java:129)
    at org.jvnet.hk2.internal.ClazzCreator.initialize(ClazzCreator.java:182)
    at org.jvnet.hk2.internal.SystemDescriptor.internalReify(SystemDescriptor.java:723)
    at org.jvnet.hk2.internal.SystemDescriptor.reify(SystemDescriptor.java:678)
    at org.jvnet.hk2.internal.ServiceLocatorImpl.reifyDescriptor(ServiceLocatorImpl.java:416)
    at org.jvnet.hk2.internal.Utilities.createService(Utilities.java:2029)
    at org.jvnet.hk2.internal.ServiceHandleImpl.getService(ServiceHandleImpl.java:105)
    at org.jvnet.hk2.internal.ServiceHandleImpl.getService(ServiceHandleImpl.java:87)
//more stack trace
MultiException stack 2 of 2
java.lang.IllegalArgumentException: Errors were discovered while reifying SystemDescriptor(
    implementation=java.util.List
    contracts={java.util.List}
    scope=org.glassfish.jersey.process.internal.RequestScoped
    qualifiers={}
    descriptorType=CLASS
    descriptorVisibility=NORMAL
    metadata=
    rank=0
    loader=null
    proxiable=null
    proxyForSameScope=null
    analysisName=null
    id=349
    locatorId=0
    identityHashCode=1585683969
    reified=false)
    at org.jvnet.hk2.internal.SystemDescriptor.reify(SystemDescriptor.java:689)
    at org.jvnet.hk2.internal.ServiceLocatorImpl.reifyDescriptor(ServiceLocatorImpl.java:416)
    at org.jvnet.hk2.internal.Utilities.createService(Utilities.java:2029)
    at org.jvnet.hk2.internal.ServiceHandleImpl.getService(ServiceHandleImpl.java:105)
    at org.jvnet.hk2.internal.ServiceHandleImpl.getService(ServiceHandleImpl.java:87)

如何编写一个接受 MyObjects 列表的 ReST 方法？

我哪里错了？

Answer 1

您应该能够将方法上的查询参数指定为列表：

@GET     
@Path("/getList")     
@Produces(MediaType.APPLICATION_JSON)    
public Response getList(@QueryParam("name") List<String> nameList) {          
    //Iterate over the list and return        
    return Response.ok(nameList).build();     
}

问题可能是由于在 bean 中使用了QueryParam，在方法上使用了BeanParam。如果您想将一堆对象作为查询参数传递（这似乎是个坏主意），您必须将它们设置为从查询参数所在的 String-only 表示中创建。

Answer 2

您可以使用由@MatrixParam 注解表示的矩阵参数列表，如下所示：

@GET
@Path("/foo")  
@Produces(MediaType.APPLICATION_JSON)    
public Response someMethod(@MatrixParam("name") List<String> name,
                           @MatrixParam("age") List<Integer> age) {
    ...
}

使用这种方法，您的 URL 将如下所示：

GET /foo;name=John;age=30;name=Jane;age=20