package easyJ.database.connection;
import java.sql.Connection;
import java.sql.SQLException;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;
import easyJ.common.EasyJException;
public class ConnectionControllerTomcatImpl implements ConnectionController,
java.io.Serializable {
private ConnectionControllerTomcatImpl() {}
private static ConnectionControllerTomcatImpl instance;
private static String dsName;
private static Context ic = null;
private static DataSource ds = null;
public static ConnectionController getInstance() {
if (instance == null)
instance = new ConnectionControllerTomcatImpl();
return instance;
}
public static void initialContext() throws EasyJException {
if (ic != null)
return;
try {
Context initCtx = new InitialContext();
/*
* 利用java:comp/env/获得应用服务器所创建的一个JNDI上下文环境（Context对象），然后再通过该Context查找获得DataSource对象
*/
ic = (Context) initCtx.lookup("java:comp/env");
} catch (NamingException ne) {
ne.printStackTrace();
String clientMessage = "服务器忙";
String location = "easyJ.database.connection.ConnectionControllerTomcatImpl.getEnvironmentContext()";
String logMessage = "can't find the environment with JNDI name 'java:comp/env' Please make sure the datasource is configured with the JNDI name.";
EasyJException ee = new EasyJException(ne, location, logMessage,
clientMessage);
throw ee;
}
}
// 取得JDBC数据源
private static void lookupDataSource() throws EasyJException {
if (ds == null) {
initialContext();
try {
ds = (DataSource) ic.lookup(dsName);
} catch (NamingException ne) {
ne.printStackTrace();
String clientMessage = "服务器忙";
String location = "easyJ.database.connection.ConnectionControllerTomcatImpl.lookupDataSource()";
String logMessage = "can't find the datasource with JNDI name "
+ dsName
+ ". Please make sure the datasource is configured with the JNDI name.";
EasyJException ee = new EasyJException(ne, location,
logMessage, clientMessage);
throw ee;
} catch (Exception e) {
if (e instanceof EasyJException) {
throw (EasyJException) e;
}
e.printStackTrace();
String clientMessage = "服务器忙";
String location = "easyJ.database.connection.ConnectionControllerTomcatImpl.lookupDataSource()";
String logMessage = "Unexcepted exception occurs, can't initial context because of exception:"
+ e.getMessage();
EasyJException ee = new EasyJException(e, location, logMessage,
clientMessage);
throw ee;
}
}
}
public Connection getConnection() throws EasyJException {
Connection conn = null;
try {
if (ds == null)
lookupDataSource();
conn = ds.getConnection();
return conn;
} catch (SQLException se) {
se.printStackTrace();
String clientMessage = "服务器忙";
String location = "easyJ.database.connection.ConnectionControllerTomcatImpl.getConnection()";
String logMessage = "can't get connection because of SQLException: "
+ se.getMessage();
EasyJException ee = new EasyJException(se, location, logMessage,
clientMessage);
throw ee;
}
}
}