Help me check String -- mail address

[nguyenlh]

in java I want to check A String as mail
I have done but i think itisn't true

[dmjpro]

in java I want to check A String as mail
I have done but i think itisn't true

Post your Code what you tried so far with Code Tags.
One more thing do you know regular expression.
Have a look at this and try it using Regular Expression.
Mind it, Reg Exp. supported in J2SE-1.5 :-)

Kind regards,
Dmjpro.

[nguyenlh]

Post your Code what you tried so far with Code Tags.
One more thing do you know regular expression.
Have a look at this and try it using Regular Expression.
Mind it, Reg Exp. supported in J2SE-1.5 :-)

Kind regards,
Dmjpro.

class StringDemo{
public static boolean isEmailAddress(String address) {
int dot,at;
dot = address.indexOf(".");
at = address.indexOf("@");
if( at ==-1 ||dot==-1|| address.length()< dot||(dot<at)&&) return false;
else return true;
}
public static void main( String[] arg){
System.out.println(isEmailAddress("lenguye..@"));
}


}
but if string conatin dot before @ i can't process

[nguyenlh]

help me !! this probelem i think it isn't difficult to you
thanks

[dmjpro]

class StringDemo{
public static boolean isEmailAddress(String address) {
int dot1,at1,dot2,at2;
dot = address.indexOf(".");
at = address.indexOf("@");
if( at ==-1 ||dot==-1|| address.length()< dot||(dot<at)&&) return false;
else return true;
}
public static void main( String[] arg){
System.out.println(isEmailAddress("lenguye..@"));
}


}
but if string conatin dot before @ i can't process

Please use Code Tags.
So you are checking that only one occurrence of "." and "@".
Right :-)
It will be possible with Regular Expression but I am not familiar with Regular Expression, so I am doing it using plain Java Code.

public static  boolean   isEmailAddress(String address) {
int dot,at;
dot1 = address.indexOf(".");
at1 =     address.indexOf("@");
dot2 = address.lastIndexOf(".");
at2 =     address.lastIndexOf("@");
if(dot1!=-1 && at1 !=-1 && dot1 != dot2 && at1 != at2) return true;
else return false;
}
 

Enjoy the code :-)
Good Luck !

Kind regards,
Dmjpro.

[r035198x]

Always use a regular expression for this stuff, something like

Pattern.compile(".+@.+\\.[a-z]+");

[nguyenlh]

Please use Code Tags.
So you are checking that only one occurrence of "." and "@".
Right :-)
It will be possible with Regular Expression but I am not familiar with Regular Expression, so I am doing it using plain Java Code.

public static  boolean   isEmailAddress(String address) {
int dot,at;
dot1 = address.indexOf(".");
at1 =     address.indexOf("@");
dot2 = address.lastIndexOf(".");
at2 =     address.lastIndexOf("@");
if(dot1!=-1 && at1 !=-1 && dot1 != dot2 && at1 != at2) return true;
else return false;
}
 

Enjoy the code :-)
Good Luck !

Kind regards,
Dmjpro.

that code above it can't run true
it's true when i input 2 dot and 2 @

[dmjpro]

that code above it can't run true
it's true when i input 2 dot and 2 @

Sorry I did a great mistake, :-(
Can't you change it yourself buddy, please apply your own brain when you have it :-)
Anyway !

if(dot1!=-1 && at1 !=-1 && dot1 == dot2 && at1 == at2) return true
else return false;
 

Kind regards,
Dmjpro.

[nguyenlh]

that code above it can't run true
it's true when i input 2 dot and 2 @

you can check this code
public boolean isEmailAddress(String address) {
int At,Dot,DO;
At = address.indexOf("@",0);
Dot = address.indexOf(".",At+1);
if(address.length() > Dot) DO = 1;
else = -1;

if((At == -1) || (Dot == -1) || (Do == -1)) return false;
return true;
}

[dmjpro]

you can check this code
public boolean isEmailAddress(String address) {
int At,Dot,DO;
At = address.indexOf("@",0);
Dot = address.indexOf(".",At+1);
if(address.length() > Dot) DO = 1;
else = -1;

if((At == -1) || (Dot == -1) || (Do == -1)) return false;
return true;
}

What about my code?

Kind regards,
Dmjpro.

[r035198x]

Throw all that stuff away and use regular expressions. They are the right tool for the job.

P.S If you guys really like to learn Java, you have to first learn to take advice.

[dmjpro]

Throw all that stuff away and use regular expressions. They are the right tool for the job.

P.S If you guys really like to learn Java, you have to first learn to take advice.

Yeah it's right, but I think if it is done then he or she can learn the logic development.
But finally he or she will do that using Reg Exp.
Don't mind Admin, if I told anything wrong.

Kind regards,
Dmjpro.

[JosAH]

Always use a regular expression for this stuff, something like

Pattern.compile(".+@.+\\.[a-z]+");

That thing accepts two or more dots next to each other and multiple at-signs
all over the place. I'm afraid the RE is more complicated than that:

1) [^\.@]+

accepts anything without dots and at-signs, so

2) [^\.@]+(\.[\.@]+)*

accepts sequences of 1) separated by a single dot. This little beast accepts
all stuff to the left of the at-sign in a (potential) email address.

The part to the right of the at-sign is similar to 2) but there's a top level domain
name as the rightmost part:

3) [^\.@]+(\.[\.@]+)*\\.[a-z]+

Now 2) and 3) together, separated by an at-sign accepts an email address:

[^\.@]+(\.[\.@]+)*@[^\.@]+(\.[\.@]+)*\\.[a-z]+

*yuck* ;-)

kind regards,

Jos

[r035198x]

That thing accepts two or more dots next to each other and multiple at-signs
all over the place. I'm afraid the RE is more complicated than that:

1) [^\.@]+

accepts anything without dots and at-signs, so

2) [^\.@]+(\.[\.@]+)*

accepts sequences of 1) separated by a single dot. This little beast accepts
all stuff to the left of the at-sign in a (potential) email address.

The part to the right of the at-sign is similar to 2) but there's a top level domain
name as the rightmost part:

3) [^\.@]+(\.[\.@]+)*\\.[a-z]+

Now 2) and 3) together, separated by an at-sign accepts an email address:

[^\.@]+(\.[\.@]+)*@[^\.@]+(\.[\.@]+)*\\.[a-z]+

*yuck* ;-)

kind regards,

Jos

I just plugged that from devx and never bothered to check it.

There's another way of doing it in parts doesn't look cleaner as well (but regexs are not always clean anyway).

So you did a match by eliminating the illegal characters, the OP doesn't want to use them anyway ...

[JosAH]

I just plugged that from devx and never bothered to check it.

There's another way of doing it in parts doesn't look cleaner as well (but regexs are not always clean anyway).

So you did a match by eliminating the illegal characters, the OP doesn't want to use them anyway ...

Ah, yes, if you assume that the email address is correct anyway, your RE:
".+@.+\\.[a-z]+" works fine of course. There's an old saying in the compiler
'world' that goes: "any fool can write a compiler for a perfect user" (no insult
intended).

kind regards,

Jos@.....@@.@.@.@....foo

[nguyenlh]

i understand that but I can't process email like sadgasdaga@gsadg.
i use address.length() but no - help me again

[nguyenlh]

That thing accepts two or more dots next to each other and multiple at-signs
all over the place. I'm afraid the RE is more complicated than that:

1) [^\.@]+

accepts anything without dots and at-signs, so

2) [^\.@]+(\.[\.@]+)*

accepts sequences of 1) separated by a single dot. This little beast accepts
all stuff to the left of the at-sign in a (potential) email address.

The part to the right of the at-sign is similar to 2) but there's a top level domain
name as the rightmost part:

3) [^\.@]+(\.[\.@]+)*\\.[a-z]+

Now 2) and 3) together, separated by an at-sign accepts an email address:

[^\.@]+(\.[\.@]+)*@[^\.@]+(\.[\.@]+)*\\.[a-z]+

*yuck* ;-)

kind regards,

Jos

i'm sorry evrybody - because i have never used regular expression and the first i do about mail

[r035198x]

i understand that but I can't process email like sadgasdaga@gsadg.
i use address.length() but no - help me again

Are you using regex for this yet?