java-classic-code/sqlrunner/RSTypeHandler.java

package com.primeton.dsp.dataservice.utils;

import com.google.common.collect.ImmutableList;
import org.apache.commons.dbutils.handlers.MapListHandler;

import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 *
 * SQL 查询，返回待类型的
 *
 * <pre>
 *
 * Created by zhaopx.
 * User: zhaopx
 * Date: 2020/4/2
 * Time: 12:12
 *
 * </pre>
 *
 * @author zhaopx
 */
public class RSTypeHandler extends MapListHandler {


    /**
     * 返回的数据类型
     */
    private List<Map<String, Object>> types = new ArrayList<>();

    @Override
    protected Map<String, Object> handleRow(ResultSet rs) throws SQLException {
        ResultSetMetaData rsmd = rs.getMetaData();
        int cols = rsmd.getColumnCount();
        for (int i = 1; i <= cols; i++) {
            String columnName = rsmd.getColumnLabel(i);
            if (null == columnName || 0 == columnName.length()) {
                columnName = rsmd.getColumnName(i);
            }

            Map<String, Object> type = new HashMap<>();
            type.put("name", columnName);
            type.put("type", rsmd.getColumnTypeName(i));
            types.add(type);
        }
        return super.handleRow(rs);
    }


    /**
     * 返回数据类型
     * @return
     */
    public List<Map<String, Object>> getTypes() {
        // 返回不可修改的类型
        return ImmutableList.copyOf(types);
    }
}