Read number of lines from a File : File Commands « File Input Output « Java

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Java » File Input Output » File CommandsScreenshots 
Read number of lines from a File
        
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

/**
*
* Copyright (c) 2006-2007 Berlin Brown and botnode.com/Berlin Research  All Rights Reserved
*
* http://www.opensource.org/licenses/bsd-license.php

* All rights reserved.

* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:

* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of the Botnode.com (Berlin Brown) nor
* the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written permission.

* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Date: 12/15/2009 
*   
* Home Page: http://botnode.com/

* Contact: Berlin Brown <berlin dot brown at gmail.com>
*/
public class Util{
    /**
     * Routine readLinesFile.
     
     @param inFile File
     @param prefixMode int
     @param prefix String
     @param maxLinesRead int
     @return String
     @throws IOException
     */
    public String readLinesFile(final File inFile, final int prefixMode, final String prefix, int maxLinesReadthrows IOException  {
        
        final StringBuffer resultBuffer = new StringBuffer(128);
        final FileInputStream stream = new FileInputStream(inFile);
        final BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
        
        try {
            String data = "";
            int lineNumber = 1;
            boolean maxReached = false;
            do {
                // Perform simple max, -1 means ignore the max value.
                maxReached = (maxLinesRead == -1false (lineNumber >= maxLinesRead);
                data = reader.readLine();
                if (data != null) {
                    final String curPrefix = prefix == null "" : prefix;
                    resultBuffer.append(curPrefix).append(lineNumber).append(':');
                    resultBuffer.append(inFile.getAbsolutePath()).append(':');
                    resultBuffer.append(data).append('\n');
                }
                lineNumber++;
            while((data != null&& !maxReached);

            // Add a line number max indicator
            if (maxReached) {
                resultBuffer.append("...\n");
                resultBuffer.append("Max of ").append(lineNumber-1).append(" lines reached for ");
                resultBuffer.append(inFile.getAbsolutePath());
                resultBuffer.append(data).append('\n');
            // End of the if //

        finally {
            if (reader != null) {
                try {
                    reader.close();
                catch (IOException e) {
                    ;
                }
            }
        // End of Finally //
        return resultBuffer.toString();
    }

}

   
    
    
    
    
    
    
    
  
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