Web School Notes

You can record the items you have used in the past, so that you can take them away without saying hello.

/***************** (1) determine whether a session is available and then determine whether the user logs in, if you log in to obtain the encapsulated information in the session ****************/

If (request. isrequestedsessionidvalid ()){
Object User = session. getattribute ("user ");
If (user = NULL ){}
Else if (user! = NULL) Users user1 = (users) user;

}

// You can also judge the jump path based on whether the value in the session is null;

First, set the default link or jump path to the prompt for user login. However, if the value obtained in the session is not empty, the jump value is changed.

Example: <%
String userlink = "userloginplease. jsp ";
Userentity user = NULL;
If (session. getattribute ("user ")! = NULL ){
User = (userentity) Session. getattribute ("user ");
Userlink = "userupdate. jsp? Name = "+ User. getname ();
}
%>

/********************************** (2) the simple JS Code prompts the input validity ******************************** **********************/

<! --------- Jquery & Ajax check is name exise --------->

$ ("# Name"). BIND ("Blur", function () {// execue when input name lose it's focus
VaR AA = Document. getelementbyid ("name"). value;
// $ ('# Check'). slidetoggle (400). siblings ("DUV"). slideup ("slow"); // check is a div's ID
$ ('# Check'). Load ('checkname. jsp? Name = '+ AA + ');

});

<! ------------------- Click a span target and show a next Div --------------------------->

$ ("# Rightmessage span"). Click (function (){
$ (This). Next ("Div"). slidetoggle (300). siblings ("DUV"). slideup ("slow ");
})

<! * ---------------------------- Create a node to show erroe message !!!! ------------------------------------------------------------->

VaR A; var B;
VaR exise = false;
VaR par = Document. getelementbyid ("username ");
VaR par1 = Document. getelementbyid ("realname ");
Function showerror (a, B) {// a parameter is the error Display object, and one is the display text;
SPAN = Document. createelement ('span ');
Span. classname = 'error ';
Span. innerhtml = B;
A. parentnode. appendchild (SPAN );
}
Function removeerror (){
A. parentnode. removechild (SPAN );
}
Function checkform (){
$ ("# Username"). BIND ("Blur", function (){
If (par. value = ""){
If (! Exise ){
Showerror (PAR, "Please enter a name! ");
Exise = true;
Document. getelementbyid ("Submit"). Disabled = true;
} Else {
Removeerror (PAR );
}
});

<! ------------------------------ Determine the number and null value ------------------------------------->

VaR passcode = Document. getelementbyid ("passcode ");
VaR name = Document. getelementbyid ("name ");
Passcode. Regexp =/^ [0-9] + $ /;
Name. Regexp =/^. + /;
Document. getelementbyid ("frm"). onsubmit = function (){
If (! Passcode. Regexp. Test (passcode. Value )){
Alert ('enter a number for the password! ');
Return false;
}
If (! Name. Regexp. Test (name. Value )){
Alert ('user name cannot be blank! ');
Return false;
}
}

/**************************** Eval () and !!! **************************************** ******************/

Function getobj (objname) // call the eval () method to execute the text according to the JS Code and return the document model of this ID object based on the input ID.
{
If (document. getelementbyid ){
Return eval ('document. getelementbyid ("'+ objname + '")');
} Else {
Return eval ('document. all. '+ objname );
}
}

// Synchronizid change input value !!!!

Function changeinput (){
Getobj ("A2"). value = getobj ("A1"). value;
SetTimeout ("changeinput ()", 100)
}

Changeinput ();

/********************************* (2) sort by Unicode ************************************ **/

Public static void main (string [] ARGs) {// Test Method
String [] arr2 = {"3", "1", "2", "ACCC", "seeee", "BDD", "dddd", "cddd ", "GG", "ZZZZ", "wwww", "KKKK", "medium", "Count", "good", "Ah", "just "};
List list = sort (arr2 );
Showlist (list );
}
Public static list sort (string [] sortarr) {// you can sort 'abcd' or '123' of a character. It is a Unicode-encoded sequence and cannot contain Chinese characters.
Arraylist list = new arraylist ();
String temp;
For (INT I = 0; I <= sortarr. Length-1; I ++ ){
For (Int J = I + 1; j <= sortarr. Length-1; j ++ ){
// Compare the objects after I with I in sequence. If the result is greater than 0, after I, switch the position and select the sort method.
If (sortarr [I]. compareto (sortarr [J])> 0 ){
Temp = sortarr [I];
Sortarr [I] = sortarr [J];
Sortarr [J] = temp;
Count ++;
}
}
List. Add (sortarr [I]);
}
Return list;
}
Public static void showlist (list) {// display the result array;
For (INT I = 0; I <list. Size (); I ++ ){
System. Out. println ("Result:" + list. Get (I ));
}
System. Out. println ("number of moves:" + count );
}
/********************************* Java getcurrenttime () **************************************** *********************/

Public String currentlytime (){
Date = new date ();
Dateformat = dateformat. getdateinstance (dateformat. Full );
Return dateformat. Format (date );
}

/*************************************** * ** Java write log ********************************** **************/

Private Static void logout (string user, string MSG, string path ){
Filewriter out = NULL;
Try {
Out = new filewriter (path, true); // The parameter true table writes information to the file in append mode.
Out. Write (User + "on ");
Out. Write (gettime. gettime () + ":"); // Add the time before the written information
Out. Write (MSG + "\ r \ n ");
Out. Close ();
} Catch (exception e ){
E. printstacktrace ();
}
}