idgeneratorpersistent.java

OA典型例子

/*
 * IDGeneratorPersistent.java
 * Generated using xgen and texen from beanpersistent.vm
 * Thu Jul 25 10:15:26 CST 2002
 */

package com.sure.util.database;

import java.sql.Connection;
import java.sql.Statement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.DatabaseMetaData;
import java.sql.BatchUpdateException;
import java.math.BigDecimal;
import com.sure.businessmodel.Page;
import java.util.*;

/**
 * （整型）ID生成器
 * @author [e-mail]
 */
public class IDGeneratorPersistent {

  public IDGeneratorPersistent(IDGenerator bean) { setBean(bean); }
  public IDGeneratorPersistent(IDGenerator bean, boolean recordExists) { setBean(bean); setRecordExists(recordExists); }

  /** class attributes */
  transient protected boolean recordExists = false;
  transient protected boolean handleConcurrency = false;
  transient protected boolean handleAutoIncrement = false;
  protected IDGenerator bean;

  public IDGenerator getBean() { return bean; }
  public void setBean(IDGenerator bean) { this.bean = bean; }
  public boolean getRecordExists() { return recordExists; }
  public void setRecordExists(boolean recordExists) { this.recordExists = recordExists; }

  /**
   * Load this object from a result set
   * If null fields are present in the table, catch the NullPointerException
   */
  public static IDGenerator load(ResultSet rs) throws SQLException {
    IDGenerator theBean = new IDGenerator ();
    try{ theBean.setName ( rs.getString("NAME") ); } catch(NullPointerException e){}
    try{ theBean.setValue ( rs.getInt("VALUE") ); } catch(NullPointerException e){}
    try{ theBean.setNextValue ( rs.getInt("NEXTVALUE") ); } catch(NullPointerException e){}
    try{ theBean.setInitValue ( rs.getInt("INITVALUE") ); } catch(NullPointerException e){}
    return theBean;
  }

  /**
   * Load a range of records from a connection, according to the where clause.
   * Returns a map of records accessible by a column value. (ie: foreign key)
   */
  public static Map loadByKey(Connection conn, String where, String colname)
    throws SQLException{

    HashMap map = new HashMap();
    Statement s = conn.createStatement();
    String sql = "SELECT NAME,VALUE,NEXTVALUE,INITVALUE FROM IDTable " + where;
    ResultSet rs = s.executeQuery( sql );
    while(rs.next()){
      IDGenerator theBean = new IDGenerator ();
      int col = rs.findColumn(colname);
      String key = rs.getString(col);
      theBean = load(rs);
      map.put(key, theBean);
    }
    rs.close();
    s.close();
    return map;
  }

  /**
   * Load a range of records from a connection, according to the where clause
   */
  public static Vector load(Connection conn, String where) throws SQLException{
    Vector beans = new Vector();
    Statement s = conn.createStatement();
    String sql = "SELECT NAME,VALUE,NEXTVALUE,INITVALUE FROM IDTable " + where;
    ResultSet rs = s.executeQuery( sql );
    while(rs.next()){
      IDGenerator theBean = new IDGenerator ();
      theBean = load(rs);
      beans.addElement(theBean);
    }
    rs.close();
    s.close();
    return beans;
  }

  /**
   * Load a range of records using a scrollable resultset and absolute cursor
   */
  public static Vector load(Connection conn, String where,
      int startRow, int rowCount) throws SQLException {
    Vector beans = new Vector();

    String sql = "SELECT NAME,VALUE,NEXTVALUE,INITVALUE FROM IDTable ";
    if(where.length() > 0)
      sql = sql + where;
    Statement s = conn.createStatement();
    int total = startRow + rowCount;

    sql = "SELECT * from (SELECT NAME,VALUE,NEXTVALUE,INITVALUE, rownum row_num FROM (" + sql + ") " +
      "WHERE rownum<" + total + ") WHERE row_num BETWEEN " + startRow + " AND " + (total-1);

    ResultSet rs = s.executeQuery( sql );
    if (!rs.next()) return beans;

    do {
      IDGenerator theBean = new IDGenerator ();
      theBean = load(rs);
      beans.addElement(theBean);
    } while(rs.next());
    rs.close();
    s.close();
    return beans;
  }

  /**
   * Load a Page of records using a scrollable resultset and absolute cursor
   */
  public static Page load(Connection conn, int startRow, int pageSize,
       String where) throws SQLException {

    int count = getCount(conn, where);
    if (count == 0) return new Page(pageSize);
    startRow = Page.getValidStart(startRow, count, pageSize);
    Vector beans = load(conn, where, startRow, pageSize);
    return new Page(beans, startRow, count, pageSize);
  }

  /**
   * Persist the record. Performs a sql update or insert.
   * The primary key will be "set" upon insert.
   * If autocommit is on, turn it off to make a transactional
   * check of the tcn field.
   */
  public void persist(Connection conn) throws SQLException{
    if(recordExists){
      if(handleConcurrency){
        //regenerate source if you want the bean to handle concurrency
      }else{
        update(conn);
      }
    }else{
      insert(conn);
    }
  }




  /**
    * Insert a new record
    */
  public void insert(Connection conn) throws SQLException {
    PreparedStatement pstmt = null;
    pstmt = conn.prepareStatement("INSERT INTO IDTable ( NAME,VALUE,NEXTVALUE,INITVALUE ) VALUES ( ?,?,?,? )");
    pstmt.setString ( 1, bean.getName() );
    pstmt.setInt ( 2, bean.getValue().intValue() );
    pstmt.setInt ( 3, bean.getNextValue().intValue() );
    pstmt.setInt ( 4, bean.getInitValue().intValue() );
    pstmt.executeUpdate();
    pstmt.close();
    recordExists = true;
  }

  /**
    * Update an existing record
    * (including the primary key)
    */
  public void update(Connection conn) throws SQLException{
    PreparedStatement pstmt = null;
    pstmt = conn.prepareStatement("UPDATE IDTable SET " +
             "NAME = ?," +
             "VALUE = ?," +
             "NEXTVALUE = ?," +
             "INITVALUE = ? " +
             "WHERE name = ?" );
    pstmt.setString ( 1, bean.getName () );
    pstmt.setInt ( 2, bean.getValue ().intValue() );
    pstmt.setInt ( 3, bean.getNextValue ().intValue() );
    pstmt.setInt ( 4, bean.getInitValue ().intValue() );
    pstmt.setString ( 5, bean.getName () );
    pstmt.executeUpdate();
    pstmt.close();
  }


  /**
    * Delete an existing record
    */
  public static void delete(Connection conn, String where) throws SQLException{
    Statement stmt = conn.createStatement();
    String sql = "DELETE FROM IDTable " + where;
    stmt.execute(sql);
    stmt.close();
  }

  /**
    * Delete an existing record using a prepared statement
    */
  public void delete(Connection conn) throws SQLException{
    PreparedStatement pstmt = null;
    pstmt = conn.prepareStatement("DELETE FROM IDTable WHERE name = ?");
    pstmt.setString( 1, bean.getName () );
    pstmt.executeUpdate();
    pstmt.close();
  }

  /**
    * get total count of a range of records from a connection, according to the where clause
    */
  protected static int getCount(Connection conn, String where) throws SQLException{
    Statement s = conn.createStatement();

    String sql = "SELECT count(NAME) FROM IDTable ";
    if(where.length() > 0)
      sql = sql + where;
    ResultSet rs = s.executeQuery( sql );

    int count = 0;
    if( rs.next()){
      count = rs.getInt(1);
    }
    rs.close();
    s.close();
    return count;
  }

}