数据库表的 MetaData 获取方式

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import org.springframework.jdbc.core.ConnectionCallback;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;

import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.*;


@Service
public class DynamicMetadataService {
    
    private final JdbcTemplate jdbcTemplate;
    
    public DynamicMetadataService(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    /**
     * 获取表的元数据信息
     * 
     * @param tableName 数据库表名
     * @return 表的元数据信息
     */
    public List<Map<String, Object>> getTableMetadata(String tableName) {
        return jdbcTemplate.execute((ConnectionCallback<List<Map<String, Object>>>) conn -> {
            DatabaseMetaData metaData = conn.getMetaData();
            try (ResultSet columns = metaData.getColumns(
                    conn.getCatalog(),
                    conn.getSchema(),
                    tableName,
                    "%"
            )) {
                return extractColumnMetadata(columns);
            }
        });
    }
    
    private List<Map<String, Object>> extractColumnMetadata(ResultSet columns) throws SQLException {
        List<Map<String, Object>> metadataList = new ArrayList<>();
        ResultSetMetaData rsMeta = columns.getMetaData();
        int columnCount = rsMeta.getColumnCount();
        
        Map<String, String> columnNameMap = new HashMap<>();
        for (int i = 0; i < columnCount; i++) {
            columnNameMap.put(rsMeta.getColumnName(i).toLowerCase(), rsMeta.getColumnLabel(i));
        }
        
        while (columns.next()) {
            Map<String, Object> columnInfo = new LinkedHashMap<>();
            // 添加所有可用元数据
            for (Map.Entry<String, String> entry : columnNameMap.entrySet()) {
                String colName = entry.getKey();
                String displayName = entry.getValue();
                columnInfo.put(displayName, columns.getObject(colName));
            }
            metadataList.add(columnInfo);
        }
        return metadataList;
    }
}