在整合springboot和elasticsearch过程中，一个分页方法响应时出现了json转换异常，当前springboot版本为1.5.3，elasticsearch中jar版本2.4.4
异常信息
首先来看服务器返回的错误1
Could not write JSON document: (was java.lang.NullPointerException) (through reference chain: org.springframework.data.elasticsearch.core.aggregation.impl.AggregatedPageImpl["facets"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.NullPointerException) (through reference chain: org.springframework.data.elasticsearch.core.aggregation.impl.AggregatedPageImpl["facets"])
1 | Failed to write HTTP message: org.springframework.http.converter.HttpMessageNotWritableException: Could not write JSON document: (was java.lang.NullPointerException) (through reference chain: org.springframework.data.elasticsearch.core.aggregation.impl.AggregatedPageImpl["facets"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.NullPointerException) (through reference chain: org.springframework.data.elasticsearch.core.aggregation.impl.AggregatedPageImpl["facets"]) |
异常代码
代码中主要就是实现es分页搜索，返回一个Page1
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4@GetMapping("/page")
public Page<ElianPrice> page(ElianPrice elianPrice,int page,int size){
return elianPriceService.pageSearch(elianPrice, page, size);
}
解决方法
经过debug发现错误是发生在spring序列化Page1
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4@GetMapping("/page")
public List<ElianPrice> page(ElianPrice elianPrice,int page,int size){
return elianPriceService.pageSearch(elianPrice, page, size).getContent();
}
这样虽然没有错误了，但是显然与我想要的分页还是有区别。再次搜索资料，找到一个更好的解决方法，
DATAES-274
这里提供转换的方法，把原来的Page1
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11private <T> Page<T> fixEmptyPage(Page<T> page) {
AggregatedPageImpl<T> aggregatedPage = (AggregatedPageImpl<T>) page;
Aggregations aggregations = aggregatedPage.getAggregations();
if (aggregations == null) {
Field field = ReflectionUtils.findField(AggregatedPageImpl.class, "aggregations");
ReflectionUtils.makeAccessible(field);
ReflectionUtils.setField(field, aggregatedPage, InternalAggregations.EMPTY);
return aggregatedPage;
}
return page;
}
这样同样不会再出现问题了，问题解决。