Reading & Writing to text file using ArrayList incorrectly

[Jack Bush]

Hi All,

I have been able to store two strings (M44110|T33010, M92603|T10350) using ArrayList<String>, which represent the result of some patient tests. Nevertheless, the order of these results have been stored correctly.

E.g. currently stored in file Snomed-Codes as -

[M44110|T33010, M92603|T10350][M44110|T33010, M92603|T10350]

Should be stored and printed out as -

M44110|T33010
M92603|T10350

Below is the detail of the source code of this program:

import java.io.*;
import java.io.IOException;
import java.lang.String;
import java.util.regex.*;
import java.util.ArrayList;

public class FindSnomedCode {

static ArrayList<String> allRecords = new ArrayList<String>();

static public ArrayList<String> getContents(File existingFile) {
StringBuffer contents = new StringBuffer();
BufferedReader input = null;
int line_number = 0;
int number_of_records = 0;
String snomedCodes = null;
ArrayList<String> complete_records = new ArrayList<String>();

try {
input = new BufferedReader( new FileReader(existingFile) );
String current_line = null;
while (( current_line = input.readLine()) != null) {

// Create a pattern to match for the "\"
Pattern p = Pattern.compile("\\\\");
// Create a matcher with an input string
Matcher m = p.matcher(current_line);
boolean beginning_of_record = m.find();
if (beginning_of_record) {
line_number = 0;
number_of_records++;
} else {
line_number++;
}

if ( (line_number == 2) && (current_line.length() != 0) ) {
snomedCodes = current_line;
System.out.println(snomedCodes);
complete_records.add(current_line);
}
}
}
catch (FileNotFoundException ex) {
ex.printStackTrace();
}
catch (IOException ex){
ex.printStackTrace();
}
finally {
try {
if (input!= null) {
input.close();
}
}
catch (IOException ex) {
ex.printStackTrace();
}
}
return complete_records;
}


static public void setContents(File reformatFile, ArrayList<String> snomedCodes)
throws FileNotFoundException, IOException {

Writer output = null;
try {
output = new BufferedWriter( new FileWriter(reformatFile) );
for (String index : snomedCodes) {
output.write( snomedCodes.toString() );
}
}
finally {
if (output != null) output.close();
}
}

static public void printContents(File existingFile) {
StringBuffer contents = new StringBuffer();
BufferedReader input = null;
int line_number = 0;
int number_of_records = 0;
String snomedCodes = null;
try {
input = new BufferedReader( new FileReader(existingFile) );
String current_line = null;
while (( current_line = input.readLine()) != null)
System.out.println(current_line);
}
catch (FileNotFoundException ex) {
ex.printStackTrace();
}
catch (IOException ex){
ex.printStackTrace();
}
finally {
try {
if (input!= null) {
input.close();
}
}
catch (IOException ex) {
ex.printStackTrace();
}
}
}

public static void main (String args[]) throws IOException {
File currentFile = new File("D:\\dummy_patient.txt");
allRecords = getContents(currentFile);

File snomedFile = new File( "D:\\Snomed-Codes.txt");
setContents(snomedFile, allRecords);
printContents(snomedFile);
}
}


There are 4 patient records in the dummy_patient.txt file but only the 1st (M44110|T33010) & 3rd (M92603|T10350) records have results in them. The 2nd & 4th records have blank results.

Lastly, could someone explain to me the difference between java.util.List & java.util.ArrayList?

I am running Netbeans 5.0, jdk1.5.0_09 on Windows XP, SP2.

Many thanks,

Netbeans Fan.

[Ken Blair]

Originally posted by Helen Tran:
Lastly, could someone explain to me the difference between java.util.List & java.util.ArrayList?

One is an interface and the other is a class that is a concrete implementation of that interface.

It's not entirely clear to me what you're trying to do. In the future please try to post code between code tags.

[Ken Blair]

If the problem is with storing the results I would suspect that

for (String index : snomedCodes) {
    output.write( snomedCodes.toString() );
}

should be

for (String index : snomedCodes) {
    output.write(index);
}

And your naming of the variable "index" is suspect since it's not an index, it's the current element in the iteration. The above is equivalent to:

Iterator itr = snomedCodes.iterator();
while (itr.hasNext()) {
    String index = itr.next();
    output.write(index);
}

It does the exact same thing, it's just cleaner and clearer to do it with the enhanced for loop.

[Ken Blair]

I just noticed you seem to want each on a new line too.

for (String code : snomedCodes) {
   output.write(code);
   output.newLine();
}