4

我的 GWT 服务返回LinkedList<VisualData>。VisualData看起来是这样的：

import javax.xml.bind.annotation.XmlRootElement;
import com.google.gwt.user.client.rpc.IsSerializable;

@XmlRootElement
public class VisualData implements IsSerializable {
    private Number value;
    private long timestamp;

    public VisualData() {
    }

    public VisualData(Number value, long timestamp) {
        this.value = value;
        this.timestamp = timestamp;
    }

    public long getTimestamp() {
        return timestamp;
    }

    public Number getValue() {
        return value;
    }

    public void setTimestamp(long timestamp) {
        this.timestamp = timestamp;
    }

    public void setValue(Number value) {
        this.value = value;
    }
}

我得到以下与 field 相关的异常private Number value。

SEVERE: The exception contained within MappableContainerException could not be mapped to a response, re-throwing to the HTTP container
org.codehaus.jackson.map.JsonMappingException: Can not deserialize instance of java.lang.Number out of START_OBJECT token
at [Source: org.apache.catalina.connector.CoyoteInputStream@a0eb51; line: 1, column: 29] (through reference chain: org.jage.charts.client.VisualData["value"])

当我更改private Number value为 时private Object value，我得到的所有 getter 和 setter：

SEVERE: WebModule[/AgECharts]Exception while dispatching incoming RPC call
com.google.gwt.user.client.rpc.SerializationException: Type 'org.jage.charts.client.VisualData' was not included in the set of types which can be serialized by this SerializationPolicy or its Class object could not be loaded. For security purposes, this type will not be serialized.: instance = Value:{@type=xs:int, $=6}, timestamp:1360240281439
at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:619)

第二种情况很清楚，Object该类不可序列化。但为什么我会得到Can not deserialize instance of java.lang.Number out of START_OBJECT token？

4

1 回答 1

9

如果不为您的字段提供其他类型信息，您将无法将数据反序列化到此对象value中。这是因为Number类是抽象的，不能被实例化。将字段更改为Object将无济于事，因为杰克逊可以将数据反序列化为该类的可写字段。

Number您应该将该字段更改为类（Integer、、Long等Double）的具体实现之一。

于 2013-02-07T17:23:56.680 回答