sql查询数据封装到List<map>中

待我称王封你为后i 2024-04-18 04:18 78阅读 0赞

package test;
    
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.ResultSetMetaData;
    import java.sql.SQLException;
    import java.sql.Statement;
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    public class SqlToListMap {
    	public static List<Map> getListMapBySql(String sql, Connection conn) {
    		// 封装数据用
    		List<Map> list = new ArrayList<Map>();// 声明返回的对象
    		PreparedStatement pstm = null;
    		ResultSet rs = null;
    		// Connection con = null;
    		try {
    			// con = ds.getConnection();
    			// 执行查询
    			pstm = conn.prepareStatement(sql);
    			rs = pstm.executeQuery();
    			// 分析结果集
    			ResultSetMetaData rsmd = rs.getMetaData();
    			// 获取列数
    			int cols = rsmd.getColumnCount();
    			// 遍历数据
    			while (rs.next()) {
    				// 一行数据
    				Map<String, String> mm = new HashMap<String, String>(4);
    				// 遍历列
    				for (int i = 0; i < cols; i++) {
    					// 获取列名
    					String colName = rsmd.getColumnLabel(i + 1);
    					// BeanCtx.out("colName="+colName);
    					// 获取数据
    					String fdValue = rs.getString(i + 1);
    
    					// String fdValue = rs.getString(fdName);
    					mm.put(colName, fdValue);
    				}
    
    				// 将这个map放到list
    				list.add(mm);
    
    			}
    		} catch (Exception e) {
    			throw new RuntimeException(e);
    
    		} finally {
    			close(conn, pstm, rs);// 释放资源
    		}
    		return list;
    	}
    
    	public static void close(Connection conn, Statement stat, ResultSet rs) {
    		if (rs != null) {
    			try {
    				rs.close();
    			} catch (SQLException ex) {
    			}
    		}
    
    		if (stat != null) {
    			try {
    				stat.close();
    			} catch (SQLException ex) {
    			}
    		}
    
    		if (conn != null) {
    			try {
    				conn.close();
    			} catch (SQLException ex) {
    			}
    		}
    
    	}
    }