23.编程实现序列化的Student（sno,sname）对象在网络上的传输package com.softeem.demo;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.io.Serializable;import java.net.ServerSocket;import java.net.Socket;class Student implements Serializable {private int sno;private String sname;public Student(int sno, String sname) {this.sno = sno;this.sname = sname;}public int getSno() {return sno;}public void setSno(int sno) {this.sno = sno;}public String getSname() {return sname;}public void setSname(String sname) {this.sname = sname;}@Overridepublic String toString() {return "学号:" + sno + ";姓名:" + sname;}}class MyClient extends Thread {@Overridepublic void run() {try {Socket s = new Socket("localhost", 9999);ObjectInputStream ois = new ObjectInputStream(s.getInputStream());Student stu = (Student) ois.readObject();System.out.println("客户端程序收到服务器端程序传输过来的学生对象>> " + stu);ois.close();s.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}class MyServer extends Thread {@Overridepublic void run() {try {ServerSocket ss = new ServerSocket(9999);Socket s = ss.accept();ObjectOutputStream ops = new ObjectOutputStream(s.getOutputStream());Student stu = new Student(1, "赵本山");ops.writeObject(stu);ops.close();s.close();ss.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}public class TestTransfer {public static void main(String[] args) {new MyServer().start();new MyClient().start();}}l JDBC24.用dom4j组件解析如下XML格式的文件：<?xml version="1.0" encoding="UTF-8"?><generator><table name="login" operation="1"><column name="username" handle="0">aaa </column><column name="password" handle="0">123 </column></table><table name="login" operation="2"><column name="id" handle="1">1 </column><column name="username" handle="0">bbb </column><column name="password" handle="0">444 </column></table><table name="login" operation="3"><column name="id" handle="1">4 </column></table></generator>规则： <table>operation 1表insert,2表update，3表delete.<column>handle 1表作为where条件,0表作为操作字段。要求：按照规则生成三条SQL语句！(即做一个方法解析xml文件生成一个含有三条SQL语句的字符串)public String parseXmltoSQL(String xmlFileName) {StringBuffer sbsql = new StringBuffer();SAXReader reader = new SAXReader();try {Document document = reader.read(new File(xmlFileName));Element element = document.getRootElement();Iterator it = element.elementIterator("table");while (it.hasNext()) {element = (Element) it.next();//获得对表的操作String oper = element.attributeValue("operation");//获得表名String tableName = element.attributeValue("name");if ("1".equals(oper)) {sbsql.append("insert into ").append(tableName);Iterator it2 = element.elementIterator("column");String columnName1 = null;String columnValue1 = null;String columnName2 = null;String columnValue2 = null;if (it2.hasNext()) {element = (Element) it2.next();columnName1 = element.attributeValue("name");columnValue1 = element.getText();}if (it2.hasNext()) {element = (Element) it2.next();columnName2 = element.attributeValue("name");columnValue2 = element.getText();}sbsql.append("("+columnName1+","+columnName2+")"+" values('"+columnValue1+"','"+columnValue2+"')\n");} elseif ("2".equals(oper)) {sbsql.append("update ").append(tableName);Iterator it2 = element.elementIterator("column");String columnName1 = null;String columnValue1 = null;String columnName2 = null;String columnValue2 = null;String columnName3 = null;String columnValue3 = null;if (it2.hasNext()) {element = (Element) it2.next();columnName1 = element.attributeValue("name");columnValue1 = element.getText();}if (it2.hasNext()) {element = (Element) it2.next();columnName2 = element.attributeValue("name");columnValue2 = element.getText();}if (it2.hasNext()) {element = (Element) it2.next();columnName3 = element.attributeValue("name");columnValue3 = element.getText();}sbsql.append(" set "+columnName2+"='"+columnValue2+"',"+columnName3+"='"+columnValue3+"' where "+columnName1+"="+columnValue1+"\n");}elseif ("3".equals(oper)) {sbsql.append("delete from ").append(tableName);Iterator it2 = element.elementIterator("column");String columnName1 = null;String columnValue1 = null;if (it2.hasNext()) {element = (Element) it2.next();columnName1 = element.attributeValue("name");columnValue1 = element.getText();}sbsql.append(" where "+columnName1+"="+columnValue1);}}} catch (DocumentException e) {// TODO Auto-generated catch blocke.printStackTrace();}return sbsql.toString();}l JSP/SERVLET25．写出JSP的内置对象并说明他们的作用request:request表示HttpServletRequest对象。它包含了有关浏览器请求的信息，并且提供了几个用于获取cookie, header数据的有用的方法。 response:response表示HttpServletResponse对象，并提供了几个用于设置送回浏览器的响应的方法（如cookies,头信息等） out:out对象是javax.jsp.JspWriter的一个实例，并提供了几个方法使你能用于向浏览器回送输出结果。 pageContext:pageContext表示一个javax.servlet.jsp.PageContext对象。它是用于方便存取各种范围的名字空间、servlet相关的对象的API，并且包装了通用的servlet相关功能的方法。 session:session表示一个请求的javax.servlet.http.HttpSession对象。Session可以存贮用户的状态信息 application:applicaton 表示一个javax.servle.ServletContext对象。这有助于查找有关servlet引擎和servlet环境的信息 config:config表示一个javax.servlet.ServletConfig对象。该对象用于存取servlet实例的初始化参数。 page:page表示从该页面产生的一个servlet实例。exception: exception对象是一个例外对象，当一个页面在运行过程中发生了例外，就产生这个对象。如果一个JSP页面要应用此对象，就必须把isErrorPage设为true，否则无法编译。他实际上是java.lang.Throwable的对象
