发表代码测试
PetStore 代码 MainServlet.java
package com.sun.j2ee.blueprints.waf.controller.web;
import java.io.PrintWriter;
import java.io.OutputStreamWriter;
import java.io.IOException;
import java.util.HashMap;
import java.util.Locale;
import javax.servlet.ServletException;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletConfig;
// J2EE Imports
import javax.naming.NamingException;
// WAF imports
import com.sun.j2ee.blueprints.waf.util.I18nUtil;
import com.sun.j2ee.blueprints.waf.exceptions.GeneralFailureException;
import com.sun.j2ee.blueprints.util.tracer.Debug;
import com.sun.j2ee.blueprints.waf.controller.web.URLMappingsXmlDAO;
import com.sun.j2ee.blueprints.waf.controller.web.RequestProcessor;
import com.sun.j2ee.blueprints.waf.controller.web.util.WebKeys;
import com.sun.j2ee.blueprints.waf.util.JNDINames;
import com.sun.j2ee.blueprints.waf.controller.web.flow.FlowHandlerException;
import com.sun.j2ee.blueprints.waf.controller.web.flow.ScreenFlowManager;
import com.sun.j2ee.blueprints.waf.controller.web.WebController;
public class MainServlet extends HttpServlet {
private ServletContext context;
private HashMap urlMappings;
private HashMap eventMappings;
private Locale defaultLocale = null;
private RequestProcessor requestProcessor;
public void init(ServletConfig config) throws ServletException {
String defaultLocaleString = config.getInitParameter("default_locale");
defaultLocale = I18nUtil.getLocaleFromString(defaultLocaleString);
this.context = config.getServletContext();
String requestMappingsURL = null;
try {
requestMappingsURL = context.getResource("/WEB-INF/mappings.xml").toString();
} catch (java.net.MalformedURLException ex) {
System.err.println("MainServlet: initializing ScreenFlowManager malformed URL exception: " + ex);
}
urlMappings = URLMappingsXmlDAO.loadRequestMappings(requestMappingsURL);
context.setAttribute(WebKeys.URL_MAPPINGS, urlMappings);
eventMappings = URLMappingsXmlDAO.loadEventMappings(requestMappingsURL);
context.setAttribute(WebKeys.EVENT_MAPPINGS, eventMappings);
getScreenFlowManager();
getRequestProcessor();
}
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException {
doProcess(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException {
doProcess(request, response);
}
private void doProcess(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException {
// set the locale of the user to default if not set
if (request.getSession().getAttribute(WebKeys.LOCALE) == null) {
request.getSession().setAttribute(WebKeys.LOCALE, defaultLocale);
}
try {
getRequestProcessor().processRequest(request);
getScreenFlowManager().forwardToNextScreen(request,response);
} catch (Throwable ex) {
String className = ex.getClass().getName();
String nextScreen = getScreenFlowManager().getExceptionScreen(ex);
// put the exception in the request
request.setAttribute("javax.servlet.jsp.jspException", ex);
if (nextScreen == null) {
// send to general error screen
ex.printStackTrace();
throw new ServletException("MainServlet: unknown exception: " + className);
}
context.getRequestDispatcher(nextScreen).forward(request, response);
}
}
private RequestProcessor getRequestProcessor() {
RequestProcessor rp = (RequestProcessor)context.getAttribute(WebKeys.REQUEST_PROCESSOR);
if ( rp == null ) {
rp = new RequestProcessor();
rp.init(context);
context.setAttribute(WebKeys.REQUEST_PROCESSOR, rp);
}
return rp;
}
private ScreenFlowManager getScreenFlowManager() {
ScreenFlowManager screenManager = (ScreenFlowManager)context.getAttribute(WebKeys.SCREEN_FLOW_MANAGER);
if (screenManager == null ) {
screenManager = new ScreenFlowManager();
screenManager.init(context);
context.setAttribute(WebKeys.SCREEN_FLOW_MANAGER, screenManager);
}
return screenManager;
}
/**
* The UrlMapping object contains information that will match
* a url to a mapping object that contains information about
* the current screen, the HTMLAction that is needed to
* process a request, and the HTMLAction that is needed
* to insure that the propper screen is displayed.
*/
private URLMapping getURLMapping(String urlPattern) {
if ((urlMappings != null) && urlMappings.containsKey(urlPattern)) {
return (URLMapping)urlMappings.get(urlPattern);
} else {
return null;
}
}
}
//读取Hibernate.cfg.xml配置文件，并读到内存中为后续操作作准备
Configuration config = new Configuration().configure();
//SessionFactory缓存了生成的SQL语句和Hibernate在运行时使用的映射元数据。
SessionFactory sessionFactory = config.buildSessionFactory();
//Session是持久层操作的基础，相当于JDBC中的Connection。
Session session = sessionFactory.openSession();
try{
//为保持事务的原子性，必须捕捉异常。所有事务都放在这一代码块里。
//操作事务时(增、删、改)必须显式的调用Transaction(默认：autoCommit=false)。
Transaction tx = session.beginTransaction();
for(int i=0; i<=1000; i++){
Student stu = new Student(...);
session.save(stu);//set value to stu
//批量更新：为防止内存不足，分成每20个一批发送过去。
if(i%20==0){session.flush();session.clear();}//不是大批量更新，则不需要写这一行
//默认时，会自动flush：查询之前、提交时。
} tx.commit();//提交事务，Hibernate不喜欢抛异常，如有需要，自己捕捉。
//查询方法。如果有必要，也可以用事务(调用Transaction)
String hql = "from Student s where s.stuNo like ? and s.Sal > ?";//Student是类而不是表
List list = session.createQuery(hql)
.setString(0, "a00_").setDouble(1, 3000.0)//设置HQL的第一二个问号取值
.list();//Hibernate里面，没有返回值的都默认返回List
StringBuffer sb = new StringBuffer();
for(Student st :(List<Student>)list){//(List<Student>)强制类型转换
sb.append(st.getOid()+" "+st.getName()+"\n");//拿到Student类里的属性
}System.out.print(sb.toString());//直接打印sb也可以，它也是调用toString，但这样写效率更高
} catch (HibernateException e) {
e.printStackTrace();
session.getTransaction().rollback();//如果事务不成功，则rollback
} finally {
session.close();//注意关闭顺序，session先关，Factory最后关(因为它可以启动多个session)
sessionFactory.close();//关闭SessionFactory，虽然这里没看到它，但在HbnUtil里开启了。
}