Flink RowData 与 Row 相互转化工具类

超、凢脫俗 2024-03-03 01:42 62阅读 0赞

### RowData与Row区别 ###

（0）都代表了一条记录。都可以设置RowKind，和列数量Aritry。  
（1）RowData 属于Table API，而Row属于Stream API  
（2）RowData 属于Table内部接口，对用户不友好。而Row使用简单。  
（3）RowData 要拿到field值必须提供列索引和LogicalType类型。而Row只需要提供列名或列索引即可。

请自己阅读注释内容。

import org.apache.flink.api.common.functions.MapFunction;
    import org.apache.flink.api.common.typeinfo.TypeInformation;
    import org.apache.flink.api.java.typeutils.ResultTypeQueryable;
    import org.apache.flink.api.java.typeutils.RowTypeInfo;
    import org.apache.flink.table.data.GenericRowData;
    import org.apache.flink.table.data.RowData;
    import org.apache.flink.table.runtime.typeutils.InternalTypeInfo;
    import org.apache.flink.table.types.DataType;
    import org.apache.flink.table.types.logical.LogicalType;
    import org.apache.flink.table.types.logical.LogicalTypeRoot;
    import org.apache.flink.table.types.logical.RowType;
    import org.apache.flink.types.Row;
    import org.apache.flink.util.Preconditions;
    
    
    import java.util.*;
    import java.util.stream.Collectors;
    
    /**
     * @author: lisai
     * @create: 2023-03-15 16:51
     * @Description:
     */
    public class RowUtils {
        
    
        public interface TypedMapFunc<IN, OUT> extends MapFunction<IN, OUT>, ResultTypeQueryable<OUT> {
        
            DataType getProducedDataType();
        }
    
        public static List<RowData.FieldGetter> getRowDataFieldGetters(DataType rowDataType) {
        
            Preconditions.checkArgument(rowDataType.getLogicalType().getTypeRoot() == LogicalTypeRoot.ROW);
            return getRowDataFieldGetters(rowDataType.getChildren().stream().map(DataType::getLogicalType).collect(Collectors.toList()));
        }
    
        public static List<RowData.FieldGetter> getRowDataFieldGetters(RowType rowType) {
        
            return getRowDataFieldGetters(rowType.getFields().stream().map(RowType.RowField::getType).collect(Collectors.toList()));
        }
    
        public static List<RowData.FieldGetter> getRowDataFieldGetters(List<LogicalType> logicalTypes) {
        
            List<RowData.FieldGetter> fieldGetterList = new ArrayList<>();
            for (int i = 0; i < logicalTypes.size(); i++) {
        
                final RowData.FieldGetter fieldGetter = RowData.createFieldGetter(logicalTypes.get(i), i);
                fieldGetterList.add(fieldGetter);
            }
            return fieldGetterList;
        }
    
        public static void copyRowData(RowData input, GenericRowData output, List<RowData.FieldGetter> fieldGetters) {
        
            for (int i = 0; i < input.getArity() && i < output.getArity(); i++) {
        
                if (input instanceof GenericRowData) {
        
                    output.setField(i, ((GenericRowData) input).getField(i));
                } else {
        
                    Preconditions.checkArgument(fieldGetters != null);
                    Object value = fieldGetters.get(i).getFieldOrNull(input);
                    output.setField(i, value);
                }
            }
        }
    
        public static TypedMapFunc<RowData, Row> getRowDataToRowMapFunc(DataType rowDataType) {
        
            LogicalType logicalType = rowDataType.getLogicalType();
            Preconditions.checkArgument(logicalType.getTypeRoot() == LogicalTypeRoot.ROW);
            return new TypedMapFunc<RowData, Row>() {
        
                private RowData.FieldGetter[] fieldGetters = getRowDataFieldGetters(rowDataType).toArray(new RowData.FieldGetter[0]);
                @Override
                public TypeInformation<Row> getProducedType() {
        
                    RowType rowType = (RowType) logicalType;
                    List<RowType.RowField> rowFields = rowType.getFields();
                    List<DataType> rowDataTypes = rowDataType.getChildren();
                    TypeInformation<?>[] fieldTypeInfos = rowDataTypes.stream().map(t -> InternalTypeInfo.of(t.getLogicalType())).toArray(TypeInformation[]::new);
                    String[] fieldNames = rowFields.stream().map(RowType.RowField::getName).toArray(String[]::new);
                    return new RowTypeInfo(fieldTypeInfos, fieldNames);
                }
    
                @Override
                public DataType getProducedDataType() {
        
                    return rowDataType.bridgedTo(Row.class);
                }
    
                @Override
                public Row map(RowData rowData) throws Exception {
        
                    Row row = new Row(rowData.getRowKind(), rowData.getArity());
                    for (int i = 0; i < rowData.getArity(); i++) {
        
                        RowData.FieldGetter fieldGetter = fieldGetters[i];
                        row.setField(i, fieldGetter.getFieldOrNull(rowData));
                    }
                    return row;
                }
            };
        }
    
        public static TypedMapFunc<Row, RowData> getRowToRowRowMapFunc(DataType rowDataType) {
        
            Preconditions.checkArgument(rowDataType.getLogicalType().getTypeRoot() == LogicalTypeRoot.ROW);
            return new TypedMapFunc<Row, RowData>() {
        
                /**
                 * @Description: 注意input Row中所有的数据类型必须是Flink Table API规定的内部类型。具体参考 {@DataTypeUtils.toInternalDataType()}
                 * @param
                 * @return TypeInformation<org.apache.flink.table.data.RowData>
                 */
                @Override
                public TypeInformation<RowData> getProducedType() {
        
                    return InternalTypeInfo.of((RowType)rowDataType.getLogicalType());
                }
    
                @Override
                public DataType getProducedDataType() {
        
                    return rowDataType.bridgedTo(RowData.class);
                }
    
                @Override
                public RowData map(Row row) throws Exception {
        
                    GenericRowData rowData = new GenericRowData(row.getKind(), row.getArity());
                    for (int i = 0; i < rowData.getArity(); i++) {
        
                        rowData.setField(i, row.getField(i));
                    }
                    return rowData;
                }
            };
        }
    
    }