JavaSE データベース構造の読み取り

package com.snail.jdbc;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;


public final class DBAnalizer {
  public static void main(String[] args) {
    String user = "RSS";
    String pass = "RSSPASS";
    String url = "jdbc:mysql://192.168.1.6:3306/RSS_READER?useUnicode=true&characterEncoding=UTF8";
    String dirver = "com.mysql.jdbc.Driver";

    try {
      Class.forName(dirver);

      Connection con = DriverManager.getConnection(url, user, pass);
      con.setReadOnly(true);

      DatabaseMetaData dbmd = con.getMetaData();
      ResultSet tableRs = dbmd.getTables("RSS_READER", "%", "%", null);

      while (tableRs.next()) {
        String category = tableRs.getString("TABLE_CAT");
        String schema = tableRs.getString("TABLE_SCHEM");
        String table = tableRs.getString("TABLE_NAME");
        
        // get Primary Keys
        ResultSet pkRs = dbmd.getPrimaryKeys(category, schema, table);
        List<String> pkList = new LinkedList<String>(); 
        while (pkRs.next()) {
          String column = pkRs.getString("COLUMN_NAME");
          pkList.add(column);
        }
        pkRs.close();
        
        // get Export Foreign Keys
        ResultSet fkRs = dbmd.getExportedKeys(category, schema, table);
        Map<String,String> exMap = new HashMap<String,String>(); 
        while (fkRs.next()) {
          String pk = fkRs.getString("PKCOLUMN_NAME");
          String foreignTable = fkRs.getString("FKTABLE_NAME");
          String foreignColumn = fkRs.getString("FKCOLUMN_NAME");
          
          String tbl = exMap.get(pk);
          if(tbl==null){
            exMap.put(pk,foreignTable+"."+foreignColumn);
          }else{
            exMap.put(pk,tbl + ", " +foreignTable+"."+foreignColumn);            
          }
        }
        fkRs.close();

        // get Import Foreign Keys
        ResultSet inRs = dbmd.getImportedKeys(category, schema, table);
        Map<String,String> inMap = new HashMap<String,String>(); 
        while (inRs.next()) {
          String fk = inRs.getString("FKCOLUMN_NAME");
          String foreignTable = inRs.getString("PKTABLE_NAME");
          String foreignColumn = inRs.getString("PKCOLUMN_NAME");

          String tbl = inMap.get(fk);
          if(tbl==null){
            inMap.put(fk,foreignTable+"."+foreignColumn);
          }else{
            inMap.put(fk,tbl + ", " +foreignTable+"."+foreignColumn);            
          }
        }
        inRs.close();

        ResultSet columnRs = dbmd.getColumns(category, schema, table, "%");
        while (columnRs.next()) {
          String column = columnRs.getString("COLUMN_NAME");
          String type = columnRs.getString("TYPE_NAME");
          String size = columnRs.getString("COLUMN_SIZE");
          String decimal = columnRs.getString("DECIMAL_DIGITS");
          String nullable = columnRs.getString("IS_NULLABLE");
 
          System.out.print(table + " " + column + " (" + type + "(" + size + "." + decimal + "))");

          if("NO".equals(nullable)){
            System.out.print(" NOT_NULL");
          }
          
          if(pkList.contains(column)){
            System.out.print(" PRIMARY_KEY");            
          }
          
          if(exMap.containsKey(column)){
            System.out.print("\t=>"+exMap.get(column));
          }

          if(inMap.containsKey(column)){
            System.out.print("\t<="+inMap.get(column));
          }
          System.out.println("");
        }
        columnRs.close();

        
      }

      tableRs.close();
      con.close();
    } catch (SQLException e) {
      e.printStackTrace();
    } catch (ClassNotFoundException e) {
      e.printStackTrace();
    }
  }
}