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is this program right to check whether string is alpha or numeric
public boolean isIntNumber(String num){
try{
Integer.parseInt(num);
} catch (NumberFormatException nfe)
{
return false;
}
return true;
}
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Well it's certainly one of doing it. What happens when you run this code passing in a string, number, null etc.?
Just say 'NO' to evaluated arguments for diadic functions! Ash
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well, it is just one method - not a complete program - but it will do what it is suposed to do.
regards
Torsten
I never finish anyth...
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vivek886 wrote: is this program right to check whether string is alpha or numeric
Technically, yes, but using exceptions in such a fashion could be costly.
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Man who follows car will be exhausted." - Confucius
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Yes, that is simple. So much so it would be insulting if we offered any help you did not ask for.
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I mean to say that m asking for the solution as m new to java. and m sorry the way i asked question .
Actually the question is write simple program.
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If you haven't guessed, no one will write your code, but we'll help you make it right.
Panic, Chaos, Destruction.
My work here is done.
or "Drink. Get drunk. Fall over." - P O'H
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is there any C structure equivalant in java
how to write following
struct
{
int data
char buffer[100];
};
equivalent in java
Trioum
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set up a bean. this struct-thing is imho a relict from old c-programming. Java uses objects. A JavaBean is a well formatted object.
http://en.wikipedia.org/wiki/JavaBean
regards
Torsten
I never finish anyth...
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Torsten suggests a bean which may well be a good answer. However, it is difficult to suggest a better alternative without knowing some more about what you are trying to achieve.
Just say 'NO' to evaluated arguments for diadic functions! Ash
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Actually I have I programme which write in file with some fixed header in files . which is in form of structure like
struct _somename
{
int somenuml;
int somenum2;
int somenum3;
char databuffer1[100];
// very long struct
};
// initialize struct
struct _somename mystruct;
mystruct.somename = 1;
//------
// ans finaly open some file and write to file
fwrite(&mystruct,1,sizeof(struct _somename));
Now I want to convert same c programme in java due to some technical reason
Trioum
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trioum wrote: Now I want to convert same c programme in java due to some technical reason
Then you have some work to do.
The original implementation made assumptions about the layout of the data in memory. Or maybe they just completely ignored it because they didn't understand it at all.
And you must determine what that layout is and then match it exactly.
For starters you will need to know the size of 'int' and whether it is big endian or little endian. You need to determine the exact binary format that the 'int' takes in memory so you can determine how it would be written to a file.
And you must do the same for every other data item in the struct.
Finally you must account for the fact that the struct might be padded at the end. So there might be one or more random bytes which are not explicitly represented in the structure.
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It's not that bad - C/C++ structs and classes are virtually identical - convert these to classes in Java and make adjustments if you're placing them on the stack in C++ - there is no automatic copy construction or assignment in Java:
public class _somename
{
public int somenuml;
public int somenum2;
public int somenum3;
public String databuffer1 = new String(new char[100]);
}
public static void test()
{
_somename mystruct = new _somename();
mystruct.somename = 1;
}
David Anton
Convert between VB, C#, C++, & Java
www.tangiblesoftwaresolutions.com
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still not able to write in the file
Trioum
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trioum wrote: still not able to write in the file
What does this mean? Please give a proper explanation of your problem so poeple can try and help you.
Just say 'NO' to evaluated arguments for diadic functions! Ash
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i want to write this object field values in file
Trioum
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Saying "I want to do ..." is neither a question nor an explanation; please try and be specific about your problem.
Just say 'NO' to evaluated arguments for diadic functions! Ash
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Make your class serialisable and write it to a binary buffer. Sorted.
Panic, Chaos, Destruction.
My work here is done.
or "Drink. Get drunk. Fall over." - P O'H
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can you send me the piece of code for writing class content to the file
Trioum
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what kind of file? do you want to have an output to some textfile or did you get stuck on how to assume values to the fields?
regards
Torsten
I never finish anyth...
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trioum wrote: can you send me the piece of code for writing class content to the file
0. Define the class as implements Serializable :
class Foo implements Serializable
{
private int bar;
}
1. Write it to a binary buffer:
Foo foo = new Foo(42);
try
{
java.io.ObjectOutputStream os =
new java.io.ObjectOutputStream(
new java.io.FileOutputStream("foobar.dat"));
os.writeObject(foo);
} catch (java.io.IOException e)
{
e.printStackTrace();
} finaly
{
os.close();
}
That's hard how?
Panic, Chaos, Destruction.
My work here is done.
or "Drink. Get drunk. Fall over." - P O'H
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That won't compile. os is out of scope in the finally block.
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there is difference i getting when writing using c and java following lines shows the difference
when I use the c code
struct _Foo
{
int one;
int two;
char buffer[50];
} ;
struct _Foo foo;
memset(&foo,'0/',sizeof(_Foo));
foo.one = 2;
foo.two = 3;
strcpy(foo.buffer,"my name is trioum");
FILE *fp;
fp = fopen("cfile.txt","wb");
if(fp)
{
fwrite(&foo,sizeof(struct _Foo),1,fp);
fclose(fp);
}
result in the file I get
my name is trioum //////////////////////////////////
but when I write the same code in java
public static class _Foo implements Serializable
{
public int one;
public int two;
public String buffer = new String(new char[50]);
}
ObjectOutputStream outputStream = null;
try
{
outputStream = new ObjectOutputStream(new FileOutputStream("javafile.txt"));
_Foo Foo = new _Foo();
Foo.one = 2;
Foo.two = 3;
Foo.buffer = "my name is trioum";
outputStream.writeObject(Foo);
}
catch (FileNotFoundException ex) {
ex.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
}
I get the result in javafile.txt
¬í sr Main$_FooDpÕGT¯_ I oneI twoL buffert Ljava/lang/String;xp t my name is trioum
But I want the result as seen in cfile.txt by c code
How can I solve the problem
Trioum
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That's because you are serializing the whole Foo object, which is not what you want.
I'm not going to write the whole thing for you but I think I would make Foo look something like this:
public class Foo {
public char one;
public char two;
public String buffer;
... etc ...
public String toExternalForm() {
StringBuilder sb = new StringBuilder();
sb.append(one);
sb.append(two);
sb.append(buffer);
... etc ...
return sb.toString();
}
}
Then to use it:
foo.one = 2;
foo.two = 3;
foo.buffer = "something";
bw = new BufferedWriter(...etc...);
bw.write(foo.toExternalForm());
bw.flush();
That's basically it, you can look up BufferedWriter and whatever else you need and you might want to be a bit more intelligent about handling nulls. (I am using char instead of int in the class Foo because if we use int then StringBuilder would give us 23something which is not what you want, if I have understood correctly.)
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