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EJB 存取 WebLogic 實戰工具類：T3 協議、JNDI 查找與連線池管理

編輯：J2EE

EJBUtil 核心功能

單例模式管理 `InitialContext`，避免重複建立開銷
封裝 WebLogic T3 協議連線參數 (`t3://localhost:7001`)
提供 EJB Home 查找、JDBC DataSource 取得連線的統一介面
異常統一包裝為 `EJBException` 簡化呼叫端處理

完整原始碼

package com.newmodern.etm.utility;

import java.util.*;
import javax.naming.*;
import javax.ejb.*;
import javax.rmi.PortableRemoteObject;
import javax.sql.*;
import java.sql.*;

public class EJBUtil {
    private static Context context = null;
    private static final String URL = "t3://localhost:7001";
    private static final String JDBC_JNDI = "jdbc/XAOracle";

    public static Object getEJBHome(String lookupName, Class homeClass) {
        try {
            if (context == null) context = getInitialContext();
            Object home = PortableRemoteObject.narrow(context.lookup(lookupName), homeClass);
            return home;
        } catch (NamingException ne) {
            throw new EJBException(ne.getMessage());
        }
    }

    public static Connection getConnection(String lookupName) {
        try {
            if (context == null) context = getInitialContext();
            DataSource ds = (DataSource) PortableRemoteObject.narrow(
                context.lookup(lookupName), DataSource.class);
            return ds.getConnection();
        } catch (NamingException | SQLException e) {
            throw new EJBException(e.getMessage());
        }
    }

    public static Connection getConnection() {
        return getConnection(JDBC_JNDI);
    }

    private static Context getInitialContext() throws NamingException {
        Properties props = new Properties();
        props.put(Context.INITIAL_CONTEXT_FACTORY, "weblogic.jndi.WLInitialContextFactory");
        props.put(Context.PROVIDER_URL, URL);
        return new InitialContext(props);
    }
}

實際呼叫範例

EJB Home 查找與建立實體

public void insertCategory(...) {
    try {
        CategoryHome home = (CategoryHome) EJBUtil.getEJBHome("MyMasterCategory", CategoryHome.class);
        home.create(codeSubscriber, systemUsed, codeCategory, codeCategoryGroup, categoryDesc, actionBy, newTimestamp);
    } catch (DuplicateKeyException e) { throw new ETMDataAlreadyExistsException(); }
    catch (RemoteException | CreateException e) { throw new ETMDataAccessException(e); }
}

JDBC 連線池操作模板

public Collection getSubscriberList() {
    Connection con = null;
    PreparedStatement pStmt = null;
    ResultSet res = null;
    try {
        con = EJBUtil.getConnection("jdbc/XAOracle");
        pStmt = con.prepareStatement(subscriberSql);
        res = pStmt.executeQuery();
        while (res.next()) {
            page.add(new SubscriberEntity(res.getString("code_subscriber"), res.getString("subscriber_name")));
        }
    } catch (SQLException e) { throw new ETMDataAccessException(e); }
    finally {
        // 標準資源關閉順序：ResultSet → Statement → Connection
        closeQuietly(res); closeQuietly(pStmt); closeQuietly(con);
    }
    return page;
}