（转）java读取数据库表信息，子段

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
/***
 *  2014-07-21日：
 *  oracle数据库， 表结构查询 ，字段信息查询，字段注释查询 
 *  表字段查询 all_tab_columns
 *  表字段注释查询 all_col_comments
 *  @author 王华荣
 * 
 */
public class OracleTable {
    private static final String DRIVER_CLASS = "oracle.jdbc.driver.OracleDriver";
    private static final String DATABASE_URL = "jdbc:oracle:thin:@192.168.1.10:1521:orcl";
    private static final String DATABASE_USER = "dev";
    private static final String DATABASE_PASSWORD = "dev";
    private static Connection con = null;
     
    public static Connection getConnection() {
        try {
            Class.forName(DRIVER_CLASS);
            con=DriverManager.getConnection(DATABASE_URL,DATABASE_USER,DATABASE_PASSWORD);
            return con;
        } catch (Exception ex) {
            System.out.println("2:"+ex.getMessage());
        }
        return con;
    }
     
    /***
     * 打印test
     * @throws SQLException
     */
    public static void sysoutStrTablePdmCloumns(String Table,String Owner) throws SQLException{
        getConnection();
         
        List<HashMap<String,String>> columns = new ArrayList<HashMap<String,String>>();
         
        try{
            Statement stmt = con.createStatement();
             
            String sql=
             "select "+
             "         comments as \"Name\","+
             "         a.column_name \"Code\","+
             "         a.DATA_TYPE as \"DataType\","+
             "         b.comments as \"Comment\","+
             "         decode(c.column_name,null,‘FALSE‘,‘TRUE‘) as \"Primary\","+
             "         decode(a.NULLABLE,‘N‘,‘TRUE‘,‘Y‘,‘FALSE‘,‘‘) as \"Mandatory\","+
             "         ‘‘ \"sequence\""+
             "   from "+
             "       all_tab_columns a, "+
             "       all_col_comments b,"+
             "       ("+
             "        select a.constraint_name, a.column_name"+
             "          from user_cons_columns a, user_constraints b"+
             "         where a.constraint_name = b.constraint_name"+
             "               and b.constraint_type = ‘P‘"+
             "               and a.table_name = ‘"+Table+"‘"+
             "       ) c"+
             "   where "+
             "     a.Table_Name=b.table_Name "+
             "     and a.column_name=b.column_name"+
             "     and a.Table_Name=‘"+Table+"‘"+
             "     and a.owner=b.owner "+
             "     and a.owner=‘"+Owner+"‘"+
             "     and a.COLUMN_NAME = c.column_name(+)" +
             "  order by a.COLUMN_ID";
            System.out.println(sql);
            ResultSet rs = stmt.executeQuery(sql);
            while (rs.next()){
                HashMap<String,String> map = new HashMap<String,String>();
                map.put("Name", rs.getString("Name"));
                map.put("Code", rs.getString("Code"));
                map.put("DataType", rs.getString("DataType"));
                map.put("Comment", rs.getString("Comment"));
                map.put("Primary", rs.getString("Primary"));
                map.put("Mandatory", rs.getString("Mandatory"));
                columns.add(map);
            }
        }
        catch (SQLException e){
            e.printStackTrace();
        }finally{
            con.close();
        }
    }
    public static void main(String[] args) throws SQLException{
         
        sysoutStrTablePdmCloumns("CT_INFO_CONTRACT_BORROW","DEV");
         
         
    }
     
}