1. 구현 소스

package client;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;

public class Tail 
{

 public static void main(String[] args) throws IOException
 {
  BufferedReader input = null;
  Reader fileReader = null;
  
  if (args != null && args.length > 0) {
      fileReader = new FileReader(args[0]);
      input = new BufferedReader(fileReader);
      String line = null;
      while (true) {

          if ((line = input.readLine()) != null) {
              System.out.println(line);
              continue;
          }

          try {
              Thread.sleep(1000L);
          } catch (InterruptedException e) {
              Thread.currentThread().interrupt();
              break;
          }
      }
  } else {
   System.out.println("입력 값을 확인 해 주세요.");
  }

  try {
   if (input != null)
    input.close();
   if (fileReader != null)
    fileReader.close();
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
}

2. 실행 결과

코멘트 달기

Posted by 미물 on 2008년 10월 2일 (목) 오후 9시 23분 00초 #

 <script type="text/javascript">
        function pageselectCallback(page_id, jq){
                $('#Searchresult').text("Showing search results "
                 +((page_id*10)+1)+"-"+((page_id*10)+10));
        }
        $(document).ready(function(){ // Create pagination element
                $("#Pagination").pagination(300, {
                        num_edge_entries: 2,
                        num_display_entries: 8,
                        callback: pageselectCallback
                });

                // Set handler for setting pagination options via form
                $("#setoptions").click(function(){
                        var opt = {callback: pageselectCallback};
                        $("input[@type=text]").each(function(){
                                opt[this.name] = this.className.match
                                (/numeric/)?parseInt(this.value):this.value;
                        });
                        // extract maxitems
                        var maxitems = opt.maxitems;
                        delete opt.maxitems;
                        // Avoid html injections in this demo
                        var htmlspecialchars =
                         { "&":"&amp;", "<":"&lt;", ">":"&gt;", '"':"&quot;"}
                        $.each(htmlspecialchars, function(k,v){
                                opt.prev_text = opt.prev_text.replace(k,v);
                                opt.next_text = opt.next_text.replace(k,v);
                        })
                        $("#Pagination").pagination(maxitems, opt);
                });

        });
</script>

  - 데모 : http://www.mimul.com/examples/pagenation/demo.htm

2. 일반 Javascript에서 사용
 - 사용 소스

 function Pager(tableName, itemsPerPage) {
    this.tableName = tableName;
    this.itemsPerPage = itemsPerPage;
    this.currentPage = 1;
    this.pages = 0;
    this.inited = false;

    this.showRecords = function(from, to) {
        var rows = document.getElementById(tableName).rows;
        // i starts from 1 to skip table header row
        for (var i = 1; i < rows.length; i++) {
            if (i < from || i > to)
                rows[i].style.display = 'none';
            else
                rows[i].style.display = '';
        }
    }

    this.showPage = function(pageNumber) {
        if (! this.inited) {
                alert("not inited");
function Pager(tableName, itemsPerPage) {
    this.tableName = tableName;
    this.itemsPerPage = itemsPerPage;
    this.currentPage = 1;
    this.pages = 0;
    this.inited = false;

    this.showRecords = function(from, to) {
        var rows = document.getElementById(tableName).rows;
        // i starts from 1 to skip table header row
        for (var i = 1; i < rows.length; i++) {
            if (i < from || i > to)
                rows[i].style.display = 'none';
            else
                rows[i].style.display = '';
        }
    }

    this.showPage = function(pageNumber) {
        if (! this.inited) {
                alert("not inited");
                return;
        }

        var oldPageAnchor = document.getElementById('pg'+
           this.currentPage);
        oldPageAnchor.className = 'pg-normal';

        this.currentPage = pageNumber;
        var newPageAnchor = document.getElementById('pg'+
          this.currentPage);
        newPageAnchor.className = 'pg-selected';

        var from = (pageNumber - 1) * itemsPerPage + 1;
        var to = from + itemsPerPage - 1;
        this.showRecords(from, to);
    }

    this.prev = function() {
        if (this.currentPage > 1)
            this.showPage(this.currentPage - 1);
    }

    this.next = function() {
        if (this.currentPage < this.pages) {
            this.showPage(this.currentPage + 1);
        }
    }

    this.init = function() {
        var rows = document.getElementById(tableName).rows;
        var records = (rows.length - 1);
        this.pages = Math.ceil(records / itemsPerPage);
        this.inited = true;
    }

    this.showPageNav = function(pagerName, positionId) {
        if (! this.inited) {
                alert("not inited");
                return;
        }
        var element = document.getElementById(positionId);

        var pagerHtml = '<span onclick="' + pagerName +
          '.prev();" class="pg-normal"> &#171 Prev </span> | ';
        for (var page = 1; page <= this.pages; page++) 
         pagerHtml += '<span id="pg' + page + '" class="pg-normal" onclick="' 
            + pagerName + '.showPage(' + page + ');">' + page + '</span> | ';
        pagerHtml += '<span onclick="'+
         pagerName+'.next();" class="pg-normal"> Next &#187;</span>';

        element.innerHTML = pagerHtml;
    }
}

 - 데모 : http://www.mimul.com/examples/pagenation/paging.html

코멘트 달기

Posted by 미물 on 2008년 10월 1일 (수) 오후 9시 35분 00초 #

JDK 1.4에서와 JDK 1.5에서 문자열을 결합할 경우 똑같은 상황이 올까요? ^^

1. 예제 소스

package client;

public class StringTest 
{
    public interface Repeatable {
        void iteration(long loopId);
    }

    public static long repeat(int times, Repeatable repeatable) {
        long initial = System.currentTimeMillis();
        for (long c = 1; c <= times; c++)
            repeatable.iteration(c);
        long elapsed = System.currentTimeMillis() - initial;
        return elapsed;
    }

    private static Repeatable stringBufferTest = new Repeatable() 
    {
        public void iteration(long loopId) {
         String alias = "a";
         StringBuffer query = new StringBuffer(300);
         query.append("SELECT ");
            query.append(alias).append(".userName, ");
            query.append(alias).append(".registerDate, ");
            query.append("sum(").append(alias).append(".duration), ");
            query.append(alias).append(".id FROM ");
            query.append(StringTest.class.getName())
            .append(" as ").append(alias);
            query.append(" ORDER BY ")
            .append(alias).append(".registerDate desc ");
            String result = query.toString();
        }
    };
    private static Repeatable stringConcatenationTest = new Repeatable() 
    {
        public void iteration(long loopId) {
            String query =
                "SELECT " +
                    "a.userName, " +
                    "a.registerDate, " +
                    "sum(a.duration), " +
                    "a.id " +
                "FROM " +
                 StringTest.class.getName() +
                    " as a " + "ORDER BY " +
                    "a.registerDate desc";
            String result = query;
        }
    };

    public static void main(String[] args) {
        int times = 1000000;
        long stringBuffElapsed, stringConcatElapsed;
        
        for (int loopCount = 1; loopCount <= 5; loopCount++) 
        {
            stringBuffElapsed = repeat(times, stringBufferTest);
            stringConcatElapsed = repeat(times, stringConcatenationTest);
            System.out.println("반복 횟수 " + loopCount);
            System.out.println("StringBuffer 처리 시간 : " + stringBuffElapsed);
            System.out.println("String  Concatenation 처리 시간 : " +
               stringConcatElapsed + "\n");
        }
    }
} 

2. 예제 결과

3. 의견
 - String객체는 immutable, StringBuffer는 mutable
 - Stringr constant expression... 컴파일시에 결정되어, StringBuffer non-constant expression..런타임에 결정된다.

 위의 String Concatenation이 StringBuffer보다 두배이상 빠르게 나오네요. 변수의 값이 런타임에 결정되는 것일 경우 StringBuffer, 아닐 경우는 String Concatenation을 사용하세요.

코멘트 달기

Posted by 미물 on 2008년 9월 28일 (일) 오후 10시 18분 00초 #

OPML을 다운 받으실려면 여기를 클릭하세요.

• 참조 사이트 : http://www.noop.nl/2008/09/top-100-blogs-for-development-managers-q3-2008.html

코멘트 달기

Posted by 미물 on 2008년 9월 27일 (토) 오후 10시 11분 00초 #