www.pudn.com > 2_15692.zip > DBConnect.java

package news.database; 
 
import java.sql.*; 
import news.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("mysql"); 
    } 
 
	/** 
	 * 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 
	 * @return 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 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("mysql",conn); 
			 
		} 
		 
	} 
}