Rest实践之POST+json总结

1.  目的

开发rest 请求创建service， 利用post 请求，并且携带message body，JSON格式，包括service的配置信息，从而实现service添加

2. 关键要点

利用 post请求传输json数据并返还json格式结果

3. 关键代码

  @POST
    @Path("/service/deploy")
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public String createService(NgmaServiceConfig  serviceconfig)
    {
        log.info("create service");
        log.info("the service config received is {}",serviceconfig);
        /**
         {
         "serviceName":"provision",
         "serviceNode":{"nodeName":"node1"},
         "serviceAttributes":{"pname":"aaa"}
          }
         */
        JsonObject json = new JsonObject();
        //generate service id randomly
        UUID  serviceID=UUID.randomUUID();
        //append other attributes for service in demo 
        serviceconfig.setServiceId(serviceID);
        NgmaServiceNode node = new NgmaServiceNode();
        node.setNodeId(UUID.fromString("24c0a3f7-5d34-48bc-8472-90f98836033b"));
        node.setNodeName("node1");
        serviceconfig.setServiceName("provision");
        serviceconfig.setServiceNode(node);
        NgmaServiceType serviceType = new NgmaServiceType();
        serviceType.setServiceTypeId(UUID.fromString("8ef879ef-3837-4d24-b53e-79c191624c52"));
        serviceconfig.setServiceType(serviceType);
        try
        {
            servicedata.saveServiceConfig(serviceconfig);
        }
        catch (PlcmStatusException e)
        {
            // TODO implement catch PlcmStatusException
            log.debug("failed to create service ", e);
            
        }
        json.addProperty("serviceUUID",serviceID.toString());
            
        return json.toString();
      
     
    }
    
    

重点分析：

 @Consumes(MediaType.APPLICATION_JSON)

  指明接受的数据类型是json格式

@Produces(MediaType.APPLICATION_JSON)

  指定返回的数据类型是json格式

NgmaServiceConfig  

post请求的json格式service信息会转为NgmaServiceConfig，主要是配置jackson，CXF与Jackson结合，jason把json序列化，反序列化映射到POJO类的属性上。详细资料可以研究jackson，其他开源实现jettison也可以实现。

此处POJO的属性必须与json的配置属性一致，包括大小写，如下所示：

{
     "serviceName":"provision",
     "serviceNode":{"nodeName":"node1"},
     "serviceAttributes":{"pname":"aaa"}

}

对应 的pojo类如下：

@XmlRootElement(name = "serviceconfig")
public class NgmaServiceConfig extends MemEntity implements Serializable
{
    /**
     * 
     */
    private static final long serialVersionUID = -6005926332718108639L;

    private UUID serviceId;
    private String serviceName;
    // private UUID nodeId;

    @NgmaRefObjectAnnotation(type = "object", getter = "getServiceNode", setter = "setServiceNode")
    private NgmaServiceNode serviceNode;

    // private UUID serviceTypeId;

    @NgmaRefObjectAnnotation(type = "object", getter = "getServiceType", setter = "setServiceType")
    private NgmaServiceType serviceType;

    @NgmaRefObjectAnnotation(type = "list", getter = "getServiceDefinedTransport", setter = "setServiceDefinedTransport")
    private List<NgmaTransport> serviceDefinedTransport;
    private Map<String, String> serviceAttributes;

刚开始，一致报错unknownpropertyexception，因为我把json格式带上了根标识，如下，

{

  serviceconfig：{
     "serviceName":"provision",
     "serviceNode":{"nodeName":"node1"},
     "serviceAttributes":{"pname":"aaa"}

    }

}

因为pojo类中配置了xmlroot，所以我想json也是，我demo的例子也的确是这样，但是不太清楚为什么现在的工程不能识别？害的我搞了很久。

@XmlRootElement(name = "serviceconfig")

4. 问题

1. 

org.apache.cxf.jaxrs.client.ClientWebApplicationException:No message body writer found forclass

配置引入jackson-jxr.jar并在spring配置文件中配置，如下：

  <jaxrs:server id="ngmaServiceStatus" address="/ngma">
    <jaxrs:serviceBeans>
      <ref bean="ngmaServiceStatusBean" />
    </jaxrs:serviceBeans>
<strong>   <span style="color:#ff6666;"><jaxrs:providers>
   <bean class="org.codehaus.jackson.jaxrs.JacksonJsonProvider"/>
   </jaxrs:providers></span></strong>

  </jaxrs:server>

2. Json格式增加xml root，一直保存 ，unknown property exception

3.  jackson支持hashmap  list等集合的属性映射。

 private Map<String, List<MyHolder>> propertyName;

class MyHolder { @JsonProperty("1") private String name; @JsonProperty("2") private String age; @JsonProperty("3") private boolean female; //getters,setters,toString }

对于的json格式如下：

{ "propertyName":{ "1":[ { "1":"value1", "2":"value2", "3":false } ] } }

5. 参考link

http://www.javatips.net/blog/2012/02/cxf-restful-tutorial

http://blog.csdn.net/unei66/article/details/12324353

http://wiki.fasterxml.com/JacksonDownload

http://cxf.apache.org/docs/jax-rs-data-bindings.html#JAX-RSDataBindings-Formpayloads

http://stackoverflow.com/questions/6312030/cxf-no-message-body-writer-found-for-class-automatically-mapping-non-simple-r