我配置了 Spring Data REST 投影，当可以找到相关数据时，它会按预期工作。但是当没有找到相关数据时，会抛出以下错误：
{
"timestamp": 1532021102433,
"status": 500,
"error": "Internal Server Error",
"exception": "org.springframework.http.converter.HttpMessageNotWritableException",
"message": "Could not write JSON document: EL1007E: Property or field 'model' cannot be found on null (through reference chain: org.springframework.hateoas.PagedResources[\"_embedded\"]->java.util.Collections$UnmodifiableMap[\"processed\"]->java.util.ArrayList[0]->org.springframework.data.rest.webmvc.json.PersistentEntityJackson2Module$ProjectionResource[\"content\"]->com.sun.proxy.$Proxy122[\"model\"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: EL1007E: Property or field 'model' cannot be found on null (through reference chain: org.springframework.hateoas.PagedResources[\"_embedded\"]->java.util.Collections$UnmodifiableMap[\"processed\"]->java.util.ArrayList[0]->org.springframework.data.rest.webmvc.json.PersistentEntityJackson2Module$ProjectionResource[\"content\"]->com.sun.proxy.$Proxy122[\"model\"])",
"path": "/processed/search/findByCompCode"
}
我的投影界面如下所示：
import org.springframework.beans.factory.annotation.Value;
import org.springframework.data.rest.core.config.Projection;
import java.util.Date;
@Projection(name = "usage-detail", types = {Usage.class})
interface UsageProjection {
String getUuid();
String getProduct();
Date getReportDate();
String …