JDBC经典之作

// JDBC RMI Database connection -- database connection object

 

package dbpool;

import java.sql.*;

public class DBConnection {

private Connection con; // Database connection object

public PreparedStatement pstmt; // SQL statement object

public ResultSet rs; // SQL query results

private boolean IsQuery; // is a query statement

private String dbHost;

private String userName;

private String password;

// private static final String JDBC_DRIVER_NAME =

// "weblogic.jdbc.oci.Driver"; //Weblogic jdbc driver

// private static final String JDBC_ORACLE = "jdbc:weblogicracle:";

private static final String JDBC_DRIVER_NAME = "oracle.jdbc.driver.OracleDriver"; // Weblogic

// jdbc

// driver

private static final String JDBC_ORACLE = "jdbcracle:thin";

public DBConnection() {

rs = null;

pstmt = null;

IsQuery = true;

con = null;

}

public DBConnection(String dbHost, String userName, String password)

throws SQLException, ClassNotFoundException {

this.dbHost = dbHost;

this.userName = userName;

this.password = password;

this.open();

}

public void open(String dbHost, String userName, String password)

throws SQLException, ClassNotFoundException {

this.dbHost = dbHost;

this.userName = userName;

this.password = password;

// Load the JDBdriver

Class.forName(JDBC_DRIVER_NAME);

// Connect to the database

con = DriverManager.getConnection(JDBC_ORACLE + dbHost, userName,

password);

// Set auto-commit to be false

con.setAutoCommit(false);

}

public void open() throws SQLException, ClassNotFoundException {

// Load the JDBdriver

Class.forName(JDBC_DRIVER_NAME);

// Connect to the database

con = DriverManager.getConnection(JDBC_ORACLE + dbHost, userName,

password);

// Set auto-commit to be false

con.setAutoCommit(false);

}

private void checkConnection() throws ClassNotFoundException {

try {

if ((con == null) || con.isClosed()) {

this.open();

}

} catch (SQLException ex) {

System.out.println("Could not obtain status of the connection: "

+ ex.getMessage());

}

}

/** Prepare a SQL statement */

public void createStatement(String sqlString) throws SQLException,

ClassNotFoundException {

this.checkConnection();

try {

if (pstmt != null)

pstmt.close();

sqlString = sqlString.toUpperCase();

if (sqlString.startsWith("SELECT "))

IsQuery = true;

else

IsQuery = false;

pstmt = con.prepareStatement(sqlString);

} catch (SQLException e) {

System.out

.println("DBConnection timed out, createStatement() reconnected");

this.open();

this.createStatement(sqlString);

}

}

/** Execute a SQL statement */

public ResultSet executeSQL() throws SQLException, ClassNotFoundException {

try {

this.checkConnection();

if (IsQuery)

rs = pstmt.executeQuery();

else

pstmt.executeUpdate();

return rs;

} catch (SQLException e) {

int err = e.getErrorCode();

if (err == 0) {

System.out

.println("DBConnection timed out, executeSQL() reconnected");

this.open();

}

throw e;

}

}

public boolean hasMoreRow() throws SQLException {

boolean result = false;

if (IsQuery) {

if (rs.next())

result = true;

else

close(); // close the connection when the query is done

}

return result;

}

public void rollback() throws SQLException {

if (!IsQuery)

con.rollback();

}

public void commit() throws SQLException {

if (!IsQuery) {

con.commit();

close(); // close the connection when the update is done

}

}

public void close() throws SQLException {

if (rs != null)

rs.close();

if (pstmt != null)

pstmt.close();

if (con != null)

con.close();

rs = null;

pstmt = null;

con = null;

}

}

转载于:https://www.cnblogs.com/growing/archive/2012/07/04/2576777.html