Thursday, June 24, 2010

Wily Code

Ok, so it all started when I encountered this curiously laborious little line of code in a client's app:
String s = String.valueOf(" ");
As I said, it's quite a laborious way to initialize a string to a space. Never mind that the code in question didn't actually need that space for anything. I thought it was quaint, and wondered what other creative idioms we might employ to initialize a string to a single space character.

So Eric Galluzzo and I came up with some "brilliant ideas." Most of the samples will actually work if you compile and run them.

New
String space = new String(MessageFormat.format(
 new String(new byte[]{123,48,125}), new String(new byte[]{32})));

Symmetrical
/*/
/*/; String space = "" + " " + ""  /* | *\ "" + " " + "" = space String ;/*/;
/*/
/*/

Bees!
String space = "b\bb\bb\bb\bb\bb\bb\bb\bb\bb\bb\bb\b ";
  // only works if you write this to something that will actually execute the backspace.

Binary-Encoded Space
String charCode = "100000";
        int chr = Integer.parseInt(charCode.substring(5)) 
         + (Integer.parseInt(charCode.substring(4, 5)) << 1)
         + (Integer.parseInt(charCode.substring(3, 4)) << 2)
         + (Integer.parseInt(charCode.substring(2, 3)) << 3)
         + (Integer.parseInt(charCode.substring(1, 2)) << 4)
         + (Integer.parseInt(charCode.substring(0, 1)) << 5);
        String space = String.valueOf((char)chr);
Bit Twiddler
String space = String.valueOf((char) (32&1 + 32&2 + 32&4 + 32&8 + 32&16 + 32&32); 

ASCII Art
String space = (
                  "#####                               " +                            
                  "#     # #####    ##    ####  ###### " +
                  "#       #    #  #  #  #    # #      " +     
                  " #####  #    # #    # #      #####  " +
                  "      # #####  ###### #      #      " +
                  "#     # #      #    # #    # #      " +
                  " #####  #      #    #  ####  ######. "  ).replaceAll("#", "").trim().replaceAll(".", " ");
Around-The-World
// get space from China
    HttpClient client = new HttpClient();
    GetMethod get = new GetMethod("http://www.china.cn");
    client.executeMethod(get);
    String response = get.getResponseBodyAsString();
    String space = response.charAt(response.indexOf(" ")) + "";
    
    // or if you're feeling more poetic, get your space from space at nasa.gov
Wait for space to come to you
DatagramSocket udpSock = new DatagramSocket(68);  // get data from DHCP requests on the network
 DatagramPacket packet = new DatagramPacket(new byte[5120], 5120);
 boolean found = false;
 while (!found) { 
   udpSock.receive(packet);
   byte[] data = packet.getData();
   Arrays.sort(data);
   int indx = Arrays.binarySearch(data, 32);
   if (indx >= 0) {
  String space = String.valueOf((char) data[indx]);
  found = true;
          }
        }

 // disclaimer: your network security group might not like you sniffing the wire, so although
        // this code works, I recommend you don't ever use it, even though it's an irresistible way
        // to initialize a string ;-)

Java Intermediate Language (IL)
0  ldc  [16]
    2  astore_1 [space]

Perl programmer
String exp = "/( {1})/";
Pattern.compile(exp)... ah forget it, I can do this in Perl without even typing anything !!

Vendor-Specific
/*
 * Thanks to Eric Galluzzo for reminding us of the importance of vendor-specific implementations!
 * I wouldn't doubt that someone, somewhere is doing this...
 */ 

import com.vendor.string.String;
import com.vendor.string.StringInitializer;
import com.vendor.string.StringUsingApplication;
 

public class MyApplication extends StringUsingApplication {

    private String myString;

    @Override
    protected void initializeStrings() {
        myString = StringInitializer.getInstance().initializeString( " " );
    }
}

String-Definition Domain Specific Language
# file space.stringdef
 define string {
    immutable
    encoding UTF-8
    locale en-us
    initialize with \s
 }
// file SomeClass.java
String space = StringDSLEngine.loadString("space.stringdef");
    
// implementation of StringDSLEngine is left to the reader as an exercise.


Enterprise Architecture

It has been recommended, in keeping with corporate architectural strategies and best practices, that the new string initialization service be designed to be as simple as possible, while leveraging key synergies across business unit infrastructure.  We have achieved this goal, and, as required by the SOA governance board, provide for all critical SLAs.

    All applications going forward will be required to use the string initialization service, as an enterprise best practice, to ensure optimal flexibility, uniformity and reliability.

    Initial development and deployment is projected to see an initial $2 million investment, it is also projected to produce $10 Million ROI per annum.

    Among key benefits of this architecture are the new character database that allows seamless support for new character encodings, a vital capability if new character sets are ever introduced.  This uniquely positions the organization to respond quickly as Unicode is retired in favor of the Intergalactic Character Set (IGCS).

Wednesday, June 23, 2010

I Love This Code

Just saw the following at a client site...

if (name != null){
  person.setName(name);
}else if (name == null){
  person.setName(null);
}

I love it.  It could only be improved by being even more explicit.

if (name.equalsIgnoreCase("Allen")) {
  person.setName("Allen");
} else if (name.equalsIgnoreCase("Bob") {
  person.setName("Bob");
} else.
   /* omitting lines in this post */
} else if (name.equalsIgnoreCase("Zuzu") {  // hand cramp at line  1087667556223
  person.setName("Zuzu:);

} else if (name == null) {
  person.setName(null);
}


The only drawback I can see to this approach is that it is open to modification under new first names, otherwise, it is brilliantly self-documenting!  ;-)

Thursday, June 17, 2010

String Literals

I was just working on some some rather messy Java code. It was doing
something pretty silly, like this:

String str = "hello" + " world," + " how " + "are" + "you?"

Of course, sometimes you want to do this, like when you have to split
your string literal across multiple lines. You might do this when
your down the unfortunate path of hard coding SQL statements -- bleh
-- or maintaining old code that does the same.

That made me wish Java had C++ string literal handling. In C++, you can write

string str = "select * "
"from nowhere"
"where "
"something = nothing"

and the compiler will concatenate all those literals for you into a
single string. Much nicer than having all those concatenation
operators floating around.

Even better, though, would be support for other languages' multi-line
string literals -- like Groovy, Scala, Python (I think) etc. So even
better is:

def str = """ select *
from nowhere
where
something = nothing """

Logic in the Data Layer

I was just listening to a conversation between two developers. One of
them said, "there should be *no logic* in the stored procedure or the
DAO..." [emphasis mine]

I hear this a lot, and I think it's wrong because it is too broad. I
agree that there should be no *business* logic in those places, but we
have to be clear about the difference between business logic, a.k.a,
business rules, and other kinds of rules or logic.

In the conversation I just heard, the logic being discussed was not a
business rule, it was a rule about how data gets stored, and what
happens in the database when a particular operation occurs. This is
data logic, and it is perfectly proper for it to be in a stored
procedure or DAO.

In general, any logic or rules that relate specifically to the data
itself -- how it is stored, where it is stored, how it is aggregated
and moved -- is data logic, and belongs to the data layer. After all,
what does my application really care about how the data gets stored,
retrieved or deleted? And remember, logical relationships between
entities are not business rules.

I admit that the line can sometimes get blurry, but let us not make
such foolish blanket statements such as "no logic of any kind here."