处理NullPoint问题

bi-server/src/main/java/com/usoftchina/bi/server/service/chart/ShowHistogramService.java

@@ -117,8 +117,8 @@ public class ShowHistogramService {
                 List<HistogramData> histogramList = showChartsMapper.getHistogramValueWithoutGroup(fieldName, tableName, condition, sort, rule);
                 if (histogramList.size() > histogramConfigInfo.getMaxCount()) {
                     chartsDataInfo.setTooMany(true);
+                    histogramList = histogramList.subList(0, histogramConfigInfo.getMaxCount());
                 }
-                histogramList = histogramList.subList(0, histogramConfigInfo.getMaxCount());
                 xAxisData = histogramList.stream().map(HistogramData::getName).collect(Collectors.toList());
                 chartsDataInfo.setxAxis(xAxisData);
                 value = histogramList.stream().map(HistogramData::getValue).collect(Collectors.toList());

bi-server/src/main/java/com/usoftchina/bi/server/service/chart/ShowLineService.java

@@ -110,8 +110,8 @@ public class ShowLineService {
                 List<HistogramData> histogramList = showChartsMapper.getHistogramValueWithoutGroup(fieldName, tableName, condition, sort, rule);
                 if (histogramList.size() > lineConfigInfo.getMaxCount()) {
                     chartsDataInfo.setTooMany(true);
+                    histogramList = histogramList.subList(0, lineConfigInfo.getMaxCount());
                 }
-                histogramList = histogramList.subList(0, lineConfigInfo.getMaxCount());
                 xAxisData = histogramList.stream().map(HistogramData::getName).collect(Collectors.toList());
                 chartsDataInfo.setxAxis(xAxisData);
                 value = histogramList.stream().map(HistogramData::getValue).collect(Collectors.toList());