设备管理系统 包括设备管理

				/**
				 *  Title  pams
				 *  @author: dzc
				 *  Company: hust
				 *  @version 1.0
				 *  Date  :   2006-04
				 *  Filename:DBConnect.java
				 **/
				
				package pams.database; 
				
				import java.sql.*;
				import pams.database.DBConnectionManager;
				
				public class DBConnect {
					private Connection conn = null;
				
					private Statement stmt = null;
				
					private PreparedStatement prepstmt = null;
				
					private DBConnectionManager dcm = null;
				
					void init() {
						dcm = DBConnectionManager.getInstance();
						conn = dcm.getConnection("sqlserver");
					}
				
					/**
					 * 构造数据库的连接和访问类
					 */
					public DBConnect() throws Exception {
						init();
						stmt = conn.createStatement();
					}
				
					public DBConnect(int resultSetType, int resultSetConcurrency)
							throws Exception {
						init();
						stmt = conn.createStatement(resultSetType, resultSetConcurrency);
					}
				
					/**
					 * 构造数据库的连接和访问类 预编译SQL语句
					 * 
					 * @param sql
					 *            SQL语句
					 */
					public DBConnect(String sql) throws Exception {
						init();
						this.prepareStatement(sql);
					}
				
					public DBConnect(String sql, int resultSetType, int resultSetConcurrency)
							throws Exception {
						init();
						this.prepareStatement(sql, resultSetType, resultSetConcurrency);
					}
				
					/**
					 * 返回连接
					 * 
					 * @return Connection 连接
					 */
					public Connection getConnection() {
						return conn;
					}
				
					/**
					 * PreparedStatement
					 * 
					 * @param  sql 预设SQL语句
					 */
					public void prepareStatement(String sql) throws SQLException {
						prepstmt = conn.prepareStatement(sql);
					}
				
					public void prepareStatement(String sql, int resultSetType,
							int resultSetConcurrency) throws SQLException {
						prepstmt = conn.prepareStatement(sql, resultSetType,
								resultSetConcurrency);
					}
				
					/**
					 * 设置对应值
					 * 
					 * @param index
					 *            参数索引
					 * @param value
					 *            对应值
					 */
					public void setString(int index, String value) throws SQLException {
						prepstmt.setString(index, value);
					}
				
					public void setInt(int index, int value) throws SQLException {
						prepstmt.setInt(index, value);
					}
				
					public void setBoolean(int index, boolean value) throws SQLException {
						prepstmt.setBoolean(index, value);
					}
				
					public void setDate(int index, Date value) throws SQLException {
						prepstmt.setDate(index, value);
					}
				
					public void setTimestamp(int index, Timestamp value) throws SQLException {
						prepstmt.setTimestamp(index, value);
					}
				
					public void setLong(int index, long value) throws SQLException {
						prepstmt.setLong(index, value);
					}
				
					public void setFloat(int index, float value) throws SQLException {
						prepstmt.setFloat(index, value);
					}
				
					public void setBytes(int index, byte[] value) throws SQLException {
						prepstmt.setBytes(index, value);
					}
				
					public void clearParameters() throws SQLException {
						prepstmt.clearParameters();
						prepstmt = null;
					}
				
					/**
					 * 返回预设状态
					 */
					public PreparedStatement getPreparedStatement() {
						return prepstmt;
					}
				
					/**
					 * 返回状态
					 * 
					 * @return Statement 状态
					 */
					public Statement getStatement() {
						return stmt;
					}
				
					/**
					 * 执行SQL语句返回字段集
					 * 
					 * @param sql
					 *            SQL语句
					 * @return ResultSet 字段集
					 */
					public ResultSet executeQuery(String sql) throws SQLException {
						if (stmt != null) {
							return stmt.executeQuery(sql);
						} else
							return null;
					}
				
					public ResultSet executeQuery() throws SQLException {
						if (prepstmt != null) {
							return prepstmt.executeQuery();
						} else
							return null;
					}
				
					/**
					 * 执行SQL语句
					 * 
					 * @param sql
					 *            SQL语句
					 */
					public void executeUpdate(String sql) throws SQLException {
						if (stmt != null)
							stmt.executeUpdate(sql);
					}
				
					public void executeUpdate() throws SQLException {
						if (prepstmt != null)
							prepstmt.executeUpdate();
					}
				
					/**
					 * 关闭连接
					 */
					public void close() throws Exception {
						if (stmt != null) {
							stmt.close();
							stmt = null;
						}
						if (prepstmt != null) {
							prepstmt.close();
							prepstmt = null;
						}
						if (conn != null) {
				
							dcm.freeConnection("sqlserver", conn);
				
						}
				
					}
				}