package cn.mldn.lxh.servlet ;
import java.io.* ;
import javax.servlet.* ;
import javax.servlet.http.* ;
public class FormServlet extends HttpServlet
{
private ServletConfig config = null ;
public void init(ServletConfig config) throws ServletException
{
this.config = config ;
}
// 表示處理get請求
public void doGet(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
{
// System.out.println("** Servlet doGet處理提交參數 ") ;
this.doPost(req,resp) ;
}
// 處理post請求
public void doPost(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
{
String name = req.getParameter("uname") ;
// 取得application對象
// ServletContext app = this.getServletContext() ;
ServletContext app = this.config.getServletContext() ;
app.setAttribute("addr","www.MLDN.cn") ;
// 取得一個session對象
HttpSession session = req.getSession() ;
session.setAttribute("sname",name) ;
// System.out.println("** Servlet doPost處理提交參數 ") ;
System.out.println("name = "+name) ;
// 重定向
resp.sendRedirect("demo.jsp") ;
}
};
/**//*
<servlet>
<servlet-name>form</servlet-name>
<servlet-class>cn.mldn.lxh.servlet.FormServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>form</servlet-name>
<url-pattern>/formServlet</url-pattern>
</servlet-mapping>
*/
初始化兩種方法
有參數與無參數
有參數的方法優先
多個地址可以映射到同一個SERVLET
配置初始化參數
form表單
<form action="formServlet" method="post">
用戶名：<input type="text" name="uname">
<input type="submit" value="提交">
</form>
下面是處理表單的servlet
package cn.mldn.lxh.servlet ;
import java.io.* ;
import javax.servlet.* ;
import javax.servlet.http.* ;
public class InitParameterServlet extends HttpServlet
{
// 初始化
// 要取得初始化參數，必須使用以下初始化方法
public void init(ServletConfig config) throws ServletException
{
// config對象中有取得初始化參數的方法：getInitParameter("參數名稱")
String ref1 = config.getInitParameter("ref1") ;
String ref2 = config.getInitParameter("ref2") ;
String dd = config.getInitParameter("DBDRIVER") ;
System.out.println("REF1 => "+ref1) ;
System.out.println("REF2 => "+ref2) ;
System.out.println("DBDRIVER => "+dd) ;
}
// 表示處理get請求
public void doGet(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
{
// System.out.println("** Servlet doGet處理 ") ;
}
// 處理post請求
public void doPost(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
{
// System.out.println("** Servlet doPost處理 ") ;
}
// 銷毀
public void destroy()
{
// System.out.println("** Servlet 銷毀 ") ;
}
};
/**//*
<servlet>
<servlet-name>param</servlet-name>
<servlet-class>cn.mldn.lxh.servlet.InitParameterServlet</servlet-class>
<load-on-startup>0</load-on-startup>
<init-param>
<param-name>ref1</param-name>
<param-value>MLDN</param-value>
</init-param>
<init-param>
<param-name>ref2</param-name>
<param-value>LiXingHua</param-value>
</init-param>
<init-param>
<param-name>DBDRIVER</param-name>
<param-value>oracle.jdbc.driver.OracleDriver</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>param</servlet-name>
<url-pattern>/ipar</url-pattern>
</servlet-mapping>
*/
學習資料下載
SERVLET是一種特殊的CGI
與CGI不同是多線程，性能很高
package cn.mldn.lxh.servlet ;
import java.io.* ;
// HttpServlet屬于javax.servlet.http包下
// ServletException屬于javax.servlet包下
import javax.servlet.* ;
// HttpServletRequest、HttpServletResponse存放在javax.servlet.http包下
import javax.servlet.http.* ;
public class SimpleServlet extends HttpServlet
{
// 表示處理get請求
public void doGet(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
{
PrintWriter out = resp.getWriter() ;
out.println("<HTML>") ;
out.println("<HEAD>") ;
out.println("<TITLE>THE FIRST SERVLET</TITLE>") ;
out.println("</HEAD>") ;
out.println("<BODY>") ;
out.println("<H1>Hello World!!!</H1>") ;
out.println("</BODY>") ;
out.println("</HTML>") ;
out.close() ;
}
public void doPost(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
{
this.doGet(request,response) ;
}
};
/**//*
<servlet>
<servlet-name>simple</servlet-name>
<servlet-class>cn.mldn.lxh.servlet.SimpleServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>simple</servlet-name>
<url-pattern>/demo</url-pattern>
</servlet-mapping>
*/
輸出 Html用out.println()
很難維護
生命周期
生老病死（與人相似）
package cn.mldn.lxh.servlet ;
import java.io.* ;
import javax.servlet.* ;
import javax.servlet.http.* ;
public class LifeCycleServlet extends HttpServlet
{
// 初始化
public void init(ServletConfig config) throws ServletException
{
System.out.println("** Servlet 初始化 ") ;
}
// 表示處理get請求
public void doGet(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
{
System.out.println("** Servlet doGet處理 ") ;
}
// 處理post請求
public void doPost(HttpServletRequest req,HttpServletResponse resp) throws IOException,ServletException
{
System.out.println("** Servlet doPost處理 ") ;
}
// 銷毀
public void destroy()
{
System.out.println("** Servlet 銷毀 ") ;
}
};
/**//*
<servlet>
<servlet-name>life</servlet-name>
<servlet-class>cn.mldn.lxh.servlet.LifeCycleServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>life</servlet-name>
<url-pattern>/lc</url-pattern>
</servlet-mapping>
*/
init
doservices
destroy
創建要求
繼承HttpServlet（先導入javax.servlet.*）必須在包中
在web－inf/class下
重寫兩個方法
doGet（req，resp）throws IOException(javax.servlet.http.*,java.io.*)
用PrintWriter輸出
修改WEB.XML文件，映射SERVLET
<servlet>
<servlet-name>simple</servlet-name>
<servlet-class>cn.mldn.lxh.servlet.SimpleServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>simple</servlet-name>
<url-pattern>/demo</url-pattern>//在地址中輸入的內容</servlet-mapping>
筆記下載
servlet只初始一次（在第一次使用servlet程序后，也可以在
容器啟動時初始化servlet程序，通過修改web.xml文件）
<load-on-startup>1</load-on-startup>
doGet,doPost(doget是輸入地址，doPost是表單請求)
destroy（服務器關閉，或者長時間不用）
注意
開發框架和配置
/**
*靜態內部類的測試
*/
import java.util.Vector;
public class StaticInnerClass{
public static void main(String[] args){
Vector vec=new Vector();
Student tom=new Student("Tom","20020410");
Student jack=new Student("jack","20020411");
Studentsmith=new Student("Smith ","20020412");
Student rose=new Student("Rose","20020413");
tom.setStudentScore(456);
jack.setStudentScore(500);
smith.setStudentScore(634);
rose.setStudentScore(414);
vec.add(tom);
vec.add(jack);
vec.add(smith);
vec.add(rose);
ArrayScore.PairScore pair=ArrayScore.minMax(vec);
System.out.println("最高分數為："+pair.getMaxScore());
System.out.println("最低的分數為：")+pair.getMinScore();
}}
class ArrayScore{
static class PairScore{
private double maxScore;
private double minScore;
public PairScore(double max,double min){
maxScore=max;
minScore=min;
}
public double getMaxScore(){
return maxScore;
}
public double getMinScore(){
return minScore;
}
}
public static PairScore minMax(Vector studentVec){
double minScore=((Student)studentVec.get(0)).getStudentScore();
double maxScore=((Student)studentVec.get(0)).getStudentScore();
for(int i=1;i<studentVec.size();i++){
double score=((Student)studentVec.get(i)).getStudentScore();
if(minScore>score)
minScore=score;
if(maxScore<score)
maxScore=score;
}
return new PairScore(maxScore,minScore);
}
}
/**
*我們設計的學生基本類
*/
class Student{
private String strName="";
private Stirng strNumber="";
private Stirng strSex="";
private String strBirthday="";
private String strSpeciality="";
private String strAddress="";
private double totalScore;//學生的總分數
public Student(String name,String number){
strName=name;
strNumber=number;
}
public String getStudentName(){
return strName;
}
public String getStudentNumber(){
return strNumber;
}
public void setStudentSex(String sex){
strSex=sex;
}
public String getStudentSex(){
return strSex;
}
public String getStudentBirthday(){
return strBirthday;
}
public void setStudentBirthday(String birthday){
strBirthday=birthday;
}
public String getStudentSpeciality(){
return strSpeciality;
}
public void setStudentSpeciality(String speciality) {
strSpeciality=speciality;
}
public String getStudentAddress(){
return strAddress;
}
public void setStudentAddress(String address){
strAddress=address;
}
public double getStudentScore(){
return totalScore;
}
public void setStudentScore(double score){
totalScore=score;
}
public String toString(){
String information ="student name="+strName+"student number="+strNumber;
if(!strSex.equals(""))
information+=",sex="+strSex;
if(!strBirthday.equals(""))
information+=",Birthday="+strBirthday;
if(!strSpeciality.equals(""))
information+=",專業＝"+strSpeciality;
if(!strAddress.equals(""))
information+=",Address="+strAddress;
return information;
}
}
摘要: /** *//**
* 我們設計的學生基本類
*/
class Student
{
private String strName = "";//學生姓名
private String&nb... 閱讀全文
public interface Person{
String getName();
String getSex();
String getBirthday();
String getAddress();
void setAddress(String strAddress);
}
/**
*測試這個程序，測試對象類型的動態綁定
*/
public class ObjectVarTest
{
public static void main(String[] args){
B b=new B();
C.method3(b);
}
}
class A{
public void method1(){
System.out.println("this is class A method1");
}
}
class B extends A{
public void method1(){
System.out.println("this is class B method1");
public void method2(){
System.out.println("this is class B method2");
}
}
class c{
public static void method3(A a){
a.method1();
}}
}
/**
*i測試數組列表的使用
*/
import java.util.ArrayList;
public class ArrayList{
public static void main(String[] args){
ArrayList list=new ArrayList();
list.add(new Student("Tom","20020410"));
list.add(new Student("Jack","20020411"));
list.add(new Student("Rose","20020412"));
for(int i =0;i<list.size();i++)
{
System.out.println((Student)list.get(i));
}}}
class Student {
private String strName="";
private String strNumber="";
private String strSex="";
private String strBirthday="";
private String strAddress="";
public Student(String name,String number){
strName=name;
strNumber=number;
}
public String getStudentName(){
return strName;
}
public String getStudentNumber() {
return strNumber;
}
public String setStudentSex(String sex)
{
strSex=sex;
}
public String getStudentSex(){
return strSex;
}
public String getStudentBirthday(){
return strBirthday;
}
public void setStudentBirthday(String birthday){
strBirthday=birthday;
}
public String getStudentSpeciality(){
return strSpeciality;}
public void setStudentSpececiality(String speciality){
strSpeciality=speciality;
}
public void setStudentAddress(String address){
strAddress=address;
}
public String toString(){
String information="student name="+strName+",student number="+strNumber;
if(!strSex.equals(""))
information+=",sex="+strSex;
if(!strBirthday.equals(""))
information+=",birthday="+strBirthday;
if(!strSpeciality.equals(""))
information+=",專業＝"+strSpeciality;
if(!strAddress.equals(""))
information+=",籍貫＝"+strAddress;
return information;
}
}