How can i wrote configuration file in Log4j

Question

iam new log4j .i have seen one small programme in log4j examples folder ..i e. shown below
Sort.java
=====
package examples;
import org.apache.log4j.PropertyConfigurator;
import org.apache.log4j.Logger;
import org.apache.log4j.Priority;
Example code for log4j to viewed in conjunction with the {@link
examples.SortAlgo SortAlgo} class.
<p>This program expects a configuration file name as its first
argument, and the size of the array to sort as the second and last
argument. See its <b>source
code</b> for more details.
<p>Play around with different values in the configuration file and
watch the changing behavior.
<p>Example configuration files can be found in <a
href="doc-files/sort1.properties">sort1.properties</a>, <a
href="doc-files/sort2.properties">sort2.properties</a>, <a
href="doc-files/sort3.properties">sort3.properties</a> and <a
href="doc-files/sort4.properties">sort4.properties</a> are supplied with the
package.
<p>If you are also interested in logging performance, then have
look at the {@link org.apache.log4j.performance.Logging} class.
@author Ceki G&uuml;lc&uuml; */
public class Sort {
static Logger logger = Logger.getLogger(Sort.class.getName());
public static void main(String[] args) {
     if(args.length != 2) {
          usage("Incorrect number of parameters.");
     int arraySize = -1;
try {
          arraySize = Integer.valueOf(args[1]).intValue();
          if(arraySize <= 0)
               usage("Negative array size.");
catch(java.lang.NumberFormatException e) {
usage("Could not number format ["+args[1]+"].");
PropertyConfigurator.configure(args[0]);
int[] intArray = new int[arraySize];
logger.info("Populating an array of " + arraySize + " elements in" +" reverse order.");
for(int i = arraySize -1 ; i >= 0; i--) {
          intArray[i] = arraySize - i - 1;
SortAlgo sa1 = new SortAlgo(intArray);
sa1.bubbleSort();
sa1.dump();
// We intentionally initilize sa2 with null.
SortAlgo sa2 = new SortAlgo(null);
logger.info("The next log statement should be an error message.");
sa2.dump();
logger.info("Exiting main method.");
static void usage(String errMsg) {
     System.err.println(errMsg);
     System.err.println("\nUsage: java org.apache.examples.Sort " + "configFile ARRAY_SIZE\n"+
"where configFile is a configuration file\n"+" ARRAY_SIZE is a positive integer.\n");
System.exit(1);
and
SortAlgo.java
==========
package examples;
import org.apache.log4j.Category;
import org.apache.log4j.NDC;
Example code for log4j to viewed in conjunction with the {@link
examples.Sort Sort} class.
<p>SortAlgo uses the bubble sort algorithm to sort an integer
array. See also its <b>source
code</b>.
@author Ceki G&uuml;lc&uuml; */
public class SortAlgo {
final static String className = SortAlgo.class.getName();
final static Category CAT = Category.getInstance(className);
final static Category OUTER = Category.getInstance(className + ".OUTER");
final static Category INNER = Category.getInstance(className + ".INNER");
final static Category DUMP = Category.getInstance(className + ".DUMP");
final static Category SWAP = Category.getInstance(className + ".SWAP");
int[] intArray;
SortAlgo(int[] intArray) {
this.intArray = intArray;
void bubbleSort() {
CAT.info( "Entered the sort method.");
for(int i = intArray.length -1; i >= 0 ; i--) {
NDC.push("i=" + i);
OUTER.debug("in outer loop.");
for(int j = 0; j < i; j++) {
     NDC.push("j=" + j);
     // It is poor practice to ship code with log staments in tight loops.
     // We do it anyway in this example.
     INNER.debug( "in inner loop.");
if(intArray[j] > intArray[j+1])
     swap(j, j+1);
     NDC.pop();
NDC.pop();
void dump() {   
if(! (this.intArray instanceof int[])) {
DUMP.error("Tried to dump an uninitialized array.");
return;
DUMP.info("Dump of integer array:");
for(int i = 0; i < this.intArray.length; i++) {
DUMP.info("Element [" + i + "]=" + this.intArray);
void swap(int l, int r) {
// It is poor practice to ship code with log staments in tight
// loops or code called potentially millions of times.
SWAP.debug( "Swapping intArray["+l+"]=" + intArray[l] +
     " and intArray["+r+"]=" + intArray[r]);
int temp = this.intArray[l];
this.intArray[l] = this.intArray[r];
this.intArray[r] = temp;
This program expects a configuration file name as its first
argument, and the size of the array to sort as the second and last
argument. See its <b>source
code</b> for more details.
please help me how can write that configuration file
thanks

Answer 1

Hi bala,
check that log4j manual I pointed to in yer previous thread.
This is a pot-boiler config file... Copy it into some file say "props.conf" and use it.
# Set root logger level to DEBUG and its only appender to A1.
log4j.rootLogger=DEBUG, A1
# A1 is set to be a ConsoleAppender.
log4j.appender.A1=org.apache.log4j.ConsoleAppender
# A1 uses PatternLayout.
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%nCheers,