TableMetadata.java

package com.github.lwhite1.tablesaw.store;

import com.github.lwhite1.tablesaw.table.Relation;
import com.github.lwhite1.tablesaw.columns.Column;
import com.google.gson.Gson;

import java.util.ArrayList;
import java.util.List;
import java.util.Objects;

/**
 * Data about a specific physical table used in it's persistence
 */
public class TableMetadata {

    private static final Gson GSON = new Gson();

    private final String name;

    private final int rowCount;

    private final List<ColumnMetadata> columnMetadataList = new ArrayList<>();

    public TableMetadata(Relation table) {
        this.name = table.name();
        this.rowCount = table.rowCount();
        for (Column column : table.columns()) {
            columnMetadataList.add(new ColumnMetadata(column));
        }
    }

    public String toJson() {
        return GSON.toJson(this);
    }

    public static TableMetadata fromJson(String jsonString) {
        return GSON.fromJson(jsonString, TableMetadata.class);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        TableMetadata that = (TableMetadata) o;
        return rowCount == that.rowCount &&
                Objects.equals(name, that.name) &&
                Objects.equals(columnMetadataList, that.columnMetadataList);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name, rowCount, columnMetadataList);
    }

    public String getName() {
        return name;
    }

    public int getRowCount() {
        return rowCount;
    }

    public List<ColumnMetadata> getColumnMetadataList() {
        return columnMetadataList;
    }
}