jsp servlet学习笔记与间传值问题

ServletServletJSP：JSPServletServletJSP。通过对象requestsession(不考虑application)完成传值。一、JSP<!--JSP<formaction="JspServlet?action=toServlet"method="post"name="f<inputname="username"type="test"<inputtype="submit"2、URLa>href<form>actionrequest.getParameter("actionrequest.getParameter("actionurl3、java片段代码，servlet只能接到request的内容。在servlet里用request.getSession().getAttribute("testSession"sessionprojectnamejsp2servletprojectContext/jsp2servlet，在地址栏里显示是在地址栏里显示是http://localhost:8080/jsp2servlet/admin，的urlweb.xml注册两次。http://localhost:8080/jsp2servlet/jsphttp://localhost:8080/jsp2servlet/admin/jsp两个会话的)，getSession都是返回当前用户的会话对象，参数的区别在于：System.out.println("SessionhasbeenSystem.out.println("Sessionis三、Servlet三、Servlet带request和session参数。在servlet里使用(request,response)。而这里的url前需要带斜线/，如“).forward(request,Stringfr="good好顺序的，现在要把第n个数插到前面的有序数中，使得这n个数javapackageimportpublicclassInsertSortDirectinsertion*@parampublicstaticint[]insertSort(int...a)inttemp=for(inti=1;i<a.length;i++)intj=i-1;temp=a[i];for(;j>=0&&temp<a[j];j--){//注意：下标0到i-a[j1]a[j];将大于temp}a[j+1]=}return}publicstaticvoidmain(String[]args)inta[]={49,38,21,97,76,13,27,49,78,34,12,5,4,99,98,54,56,17,18,23,34,15,35,25,53,51for(inti=0;i<a.length;i++)System.out.print(a[i]+"}}web.xmlfilterpublicvoidinit(FilterConfigconfig)publicvoidinit(FilterConfigconfig)throwsServletException//jsonLocale=config.getInitParameter("jsonLocale");requestEncoding=config.getInitParameter("requestEncoding");responseEncodingRec=responseEncodingSend=StringconnectTimeout=StringreadTimeout=config.getInitParameter("readTimeout");}ServletContextsContext= ServletContextsContext=StringserviceCertificateFile="WEB-INF/classes/sslserver.der"; config=newInputStreamfis=publicSerializableadd(Tobj)return}publicSerializablesave(Tobj)return}String[]sessionId=session_value.split(";");retArr[1]=sessionId[0];is:"+sessionId[0]);}*@parampublicstaticStringgetCookies(HttpURLConnection{StringBuffercookies=newMap<String,List<String>>headerMap=Iterator<String>iterator=Stringheader=Stringvalue=headerMap.get(header).get(0);String[]values=value.split(";");for(inti=0;i<values.length;i++)if{}}}}return}if{huc.setRequestProperty("Cookie",}“JSESSIONID=9F15B4980661B4E8F34F63A75ED69A4A” cookie)也可以，说protectedvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOException{Enumeratione=ctobj=e.nextElement();Stringkey=(String)obj;Stringmessage="key:\t"+key;message="headervalue:\t"+headerValue;}} headervalue:localhost:8080 headervalue:keep-alive headervalue:max-age=0 headervalue: headervalue:Mozilla/5.0(WindowsNT6.1;WOW64)AppleWebKit/537.36(KHTML,likeGecko)Chrome/33.0.1750.154Safari/537.36 headervalue:gzip,deflate,sdch headervalue:zh- headervalue:06:8080 headervalue:keep-alive headervalue:no-cache headervalue:no-cache headervalue: headervalue: headervalue:Mozilla/5.0(Linux;U;Android4.1.1;en-cn;HTCT528d)key:accept-headervalue:key:accept-languageheadervalue:en-CN,en-USkey:accept-charsetheadervalue:utf-8,iso-8859-1,utf-16,Cookie[]cookies=request.getCookies();Cookiecook=null;booleanflag=false;if(cookies!=null)for(Cookiec:cookies)if{c.setValue(Integer.parseInt(c.getValue())+1cook=c;flag=true;}}if(!flag)cook=newCookie("count",}}elsecook=newCookie("count",}UserStudentuser=newif(cookies!=null)for(Cookiec:cookies)}if{}}}见Cookie[]cookies=request.getCookies();Stringusername33="";if(cookies!=null)for(Cookiec:cookies)/*if{if{username33=URLDecoder.decode(c.getValue(),"utf-8");break;}}}随机 packagepackageimportjava.awt.Color;importjava.awt.Font;importimportjava.util.Random;importjavax.imageio.ImageIO;importjavax.servlet.ServletOutputStream;importjavax.servlet.http.HttpServlet;importjavax.servlet.http.HttpSession;@author@since{privateintwidth=60,height=throwsServletException,IOException{////Graphicsg=////Randomr=new//Fontf=newFont("TimesNewRoman",Font.PLAIN,18);//g.drawRect(0,0,width-1,height-1);//for(inti=0;i<160;{intx=r.nextInt(width);inty==r.nextInt(12);inty1=g.drawLine(x,y,x+x1,y+}intred=0,green=0,blue=0;取随机产生的认证码(4位数字)for(inti=0;i<4;i++){StringstrRand=red=r.nextInt(110);blue=r.nextInt(50);//g.setColor(newColor(red,green,//将认证码显示到图象中g.drawString(strRan