Sort the output in Hadoop Mapreduce - hadoop

Question

I am a beginner using Hadoop and I want to read a text file through MapReduce and output it. I have set up a counter to see the order of the data, but the output is not in order. Here are my code and screenshot.
Question: How can we sort the output based on the value of the key?
Sample input data in text file:
199907 21 22 23 24 25
199808 26 27 28 29 30
199909 31 32 33 34 35
200010 36 37 38 39 40
200411 41 42 43 44 45
Mapper
public static class TestMapper
extends Mapper<LongWritable, Text, Text, Text>{
int days = 1;
#Override
public void map(LongWritable key, Text value, Context context
) throws IOException, InterruptedException {
/* get the file name */
FileSplit fileSplit = (FileSplit)context.getInputSplit();
String filename = fileSplit.getPath().getName();
//context.write(new Text(filename), new Text(""));
StringTokenizer token = new StringTokenizer(value.toString());
String yearMonth = token.nextToken();
if(Integer.parseInt(yearMonth) ==0)
return;
while(token.hasMoreTokens()){
context.write(new Text(yearMonth+" "+days),new Text(token.nextToken()));
}
days++;
}
}
Reducer
public static class TestReducer
extends Reducer<Text,Text,Text,Text> {
#Override
public void reduce(Text key, Iterable<Text> values,Context context)
throws IOException, InterruptedException {
ArrayList<String> valList = new ArrayList<String>();
for(Text val: values)
valList.add(val.toString());
context.write(key,new Text(valList.toString()));
}
}
Driver/Main class
public static void main(String[] args) throws Exception {
Configuration conf = new Configuration();
String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
if (otherArgs.length < 2) {
System.err.println("Usage: Class name <in> [<in>...] <out>");
System.exit(2);
}
Job job = Job.getInstance(conf, "My Class");
job.addFileToClassPath(new Path("/myPath"));
job.setJarByClass(myJar.class);
job.setMapperClass(TestMapper.class);
job.setReducerClass(TestReducer.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(Text.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(Text.class);
FileInputFormat.setInputDirRecursive(job, true);
for (int i = 0; i < otherArgs.length - 1; ++i) {
FileInputFormat.addInputPath(job, new Path(otherArgs[i]));
}
FileOutputFormat.setOutputPath(job, new Path(otherArgs[otherArgs.length - 1]));
System.exit(job.waitForCompletion(true) ? 0 : 1);
}
Screenshot part of the output