How to create a backup file if the file exists - java

I would like to create a backup backup_autoexec" + value + ".cfg of my file autoexec.cfg if it exists. If there is also already and backup then it should increase the value number. for example backup1, backup2, backup3...
public class Backup {
private int value1 = 0;
private String value;
private File file = new File("autoexec.cfg");
private boolean exists = file.exists();
private Path backup;
private Path auto = Paths.get("autoexec.cfg");
public void kopie() {
if(exists) {
while(exists) {
System.out.println("test");
value1 += 1;
value = String.valueOf(value1);
file = new File("backup_autoexec" + value + ".cfg");
backup = Paths.get("backup_autoexec" + value + ".cfg");
}
try {
Files.move(auto, backup);
}
catch (IOException f) {
f.printStackTrace();
}
}
}
}
atm it will hang into the while loop for ever and I dont know why.

You check the existence only once - for the first file. Here is a minimal working example:
int index = 1;
while (true) {
final String source = "autoexec" + index + ".txt";
if (new File(source).exists()) {
Files.copy(Paths.get(source), Paths.get(path + "\\backup_file" + index + ".txt"));
index++;
} else {
break;
}
}

it should leave the loop if no file could be found with an existing name

Related

I'm having trouble setting the value of a variable that will update my test

My problem is in the part where I'm doing the "if/else" conditions, when I call the function that will perform the comparisons and will define if the test passed or not and will send some information, I'm receiving null.
Problems are among the asterisks. If anyone can help me
This is my code :
public static void fxSpot_GBP_JPY(TradeData data, TradeData output) throws Exception {
if (data == null) {
fail("The input data object was not correctly filled");
}
if (output == null) {
fail("The output data object was not correctly filled");
}
//Used to set the comment, the status and update to JIRA
FieldsJSON fields = new FieldsJSON();
String assertionError = "";
List<String> inputs = new ArrayList<String>();
List<String> outputs = new ArrayList<String>();
String newDate = Utils.formatTimeZoneMinute(data.getTradeDate());
String asOfTrade = Utils.formatTimeZoneMinute(data.getAsOfTradeDate());
String executionDate = Utils.formatTimeZoneMinute(output.getExecutionDateTime());
try {
//Add the data in the list
inputs.add(data.getTransactionNumber()); outputs.add(output.getBloombergId());
inputs.add(newDate); outputs.add(output.getTradeDate());
inputs.add(asOfTrade); outputs.add(executionDate);
inputs.add(data.getSettlementDate()); outputs.add(output.getValueDate());
inputs.add(data.getTradeAmount()); outputs.add(output.getAmount2());
inputs.add(data.getCustomerAccountCounterparty()); outputs.add(output.getMiPartyId());
inputs.add(data.getPrincipalLoanAmount()); outputs.add(output.getAmount());
inputs.add(data.getSecurityPrice()); outputs.add(output.getRate());
inputs.add(data.getISOCodeOf1stCurrency()); outputs.add("BRL");//output.getCurrency2()
inputs.add(data.getISOCodeOf2ndCurrency()); outputs.add(output.getCurrency1());
//Compare values
System.out.println("-------------------");
int y = 0;
int x = 0;
for(String input : inputs) {
for(String out : outputs) {
if(y == x) {
if(input.equals(out)) {
WriterCSV.setOk("Ok");
**String comment = input + " = " + out;
fields.setComment(comment);
fields.setStatus("PASS");**
System.out.println("ok - " + input + " = " + out);
}else {
WriterCSV.setOk("not Ok");
**String comment = input + " = " + out;
fields.setComment(comment);
fields.setStatus("FAIL");**
System.out.println("not Ok - " + input + " = " + out);
}
}
x = x+1; // count of the list of output
}
y = y+1; // count of the list of inputs
x = 0; // reset to 0 the count of outputs
}
// evidence with the name and value of fields compared
WriterCSV.reportSpot_CSV(data,output);
}
Here is my test:
#Test
#Tag("compare")
public void CompareSpot() throws Exception {
//Create a list to read the CSVfile
List<DTOTradeData> dto;
//Used to get the TradeData of list dto.
DTOTradeData dtd = new DTOTradeData();
// Read a csvFile and return a list with the values to new xml
dto = CSVReader.readCSV("spot.csv");
//The xpath of xml
FileDriverSpot spot = new FileDriverSpot();
FileDriver output = new FileDriverSpotOutput();
FieldsJSON fields = new FieldsJSON();
//new xml = dataInput and the outputFile = dataOutput
TradeData dataInput = new TradeData();
TradeData dataOutput = new TradeData();
for (int i = 0; i < dto.size(); i++) {
dtd = dto.get(i); // get TradeData
dtd.getTradeData().setDriver(spot); // set the driver
if (fileExist(Setup.xmlPath + dtd.getInputFile() + ".xml")) {
dataInput = Reader.read(spot, Setup.xmlPath + dtd.getInputFile() + ".xml");
dataOutput = Reader.read(output, Setup.spotPath + dtd.getOutputFile());
try {
// make the comparison
**FunctionalTest.fxSpot_GBP_JPY(dataInput, dataOutput);**
}
catch(AssertionError e) {
String comment = e.toString();
fields.setComment(comment);
}
} else {
fail("The file: " + dtd.getTemplateFile()
+ " needs to go through the writing process before being compared.");
}
//Convert the file to base64
String inputData = UpdateTestStatus.convertToBase64(Setup.xmlPath + dtd.getInputFile() + ".xml");
String outputData = UpdateTestStatus.convertToBase64(Setup.spotPath + dtd.getOutputFile());
String evidenceCompared = UpdateTestStatus.convertToBase64(Setup.reportPath+"ReportSpot.csv");
System.out.println(UpdateTestStatus.updateTestRun(**fields.getStatus(),fields.getComment()**,
inputData,dtd.getInputFile()+ ".xml", //data of the XML and the name of the file
outputData,dtd.getOutputFile(),
evidenceCompared,"ReportSpot.csv",
Setup.testExec, dtd.getJiraId()).asString()); // ID testExecution and ID of
}
}
The test and the code under test each create a separate instance of FieldsJSON. Data set in one instance will not be visible in the other (unless the data is declared static, in which case there's no need to create instances).
You can fix this by using a single instance, either passed to the fxSpot_GBP_JPY method from the test, or returned from that method to the test.

TreeMap with (String,ArrayList<String,Int>)

I am trying to read an input file. Each value of the input file is inserted into the TreeMap as
If word is not existing: Insert the word to the treemap and associate the word with an ArrayList(docId, Count).
If the Word is present in the TreeMap, then check if the current DocID matches within the ArrayList and then increase the count.
THe
For the ArrayList, I created another class as below:
public class CountPerDocument
{
private final String documentId;
private final int count;
CountPerDocument(String documentId, int count)
{
this.documentId = documentId;
this.count = count;
}
public String getDocumentId()
{
return this.documentId;
}
public int getCount()
{
return this.count;
}
}
After that, I am trying to print the TreeMap into a text file as <DocID - Count>
Not sure what I am doing wrong here, but the output I get is as follows:
The Stem is todai:[CountPerDocument#5caf905d, CountPerDocument#27716f4, CountPerDocument#8efb846, CountPerDocument#2a84aee7, CountPerDocument#a09ee92, CountPerDocument#30f39991]
Wondering if anyone can guide me what i am doing wrong and if my method isn't correct what am i supposed to do?
public class StemTreeMap
{
private static final String r1 = "\\$DOC";
private static final String r2 = "\\$TITLE";
private static final String r3 = "\\$TEXT";
private static Pattern p1,p2,p3;
private static Matcher m1,m2,m3;
public static void main(String[] args)
{
BufferedReader rd,rd1;
String docid = null;
String id;
int tf = 0;
//CountPerDocument cp = new CountPerDocument(docid, count);
List<CountPerDocument> ls = new ArrayList<>();
Map<String,List<CountPerDocument>> mp = new TreeMap<>();
try
{
rd = new BufferedReader(new FileReader(args[0]));
rd1= new BufferedReader(new FileReader(args[0]));
int docCount = 0;
String line = rd.readLine();
p1 = Pattern.compile(r1);
p2 = Pattern.compile(r2);
p3 = Pattern.compile(r3);
while(line != null)
{
m1 = p1.matcher(line);
m2 = p2.matcher(line);
m3 = p3.matcher(line);
if(m1.find())
{
docid = line.substring(5, line.length());
docCount++;
//System.out.println("The Document ID is :");
//System.out.println(docid);
line = rd.readLine();
}
if(m2.find()||m3.find())
{
line = rd.readLine();
}
else
{
if(!(mp.containsKey(line))) // if the stem is not on the TreeMap
{
//System.out.println("The stem is not present in the tree");
tf = 1;
ls.add(new CountPerDocument(docid,tf));
mp.put(line, ls);
line = rd.readLine();
}
else
{
if(ls.indexOf(docid) > 0) //if its last entry matches the current document number
{
//System.out.println("The Stem is present for the same docid so incrementing docid");
tf = tf+1;
ls.add(new CountPerDocument(docid,tf));
line = rd.readLine();
}
else
{
//System.out.println("Stem is present but not the same docid so inserting new docid");
tf = 1;
ls.add(new CountPerDocument(docid,tf)); //set did to the current document number and tf to 1
line = rd.readLine();
}
}
}
}
rd.close();
System.out.println("The Number of Documents in the file is:"+ docCount);
//Write to an output file
String l = rd1.readLine();
File f = new File("dictionary.txt");
if (f.createNewFile())
{
System.out.println("File created: " + f.getName());
}
else
{
System.out.println("File already exists.");
Path path = Paths.get("dictionary.txt");
Files.deleteIfExists(path);
System.out.println("Deleted Existing File:: Creating New File");
f.createNewFile();
}
FileWriter fw = new FileWriter("dictionary.txt");
fw.write("The Total Number of Stems: " + mp.size() +"\n");
fw.close();
System.out.println("The Stem is todai:" + mp.get("todai"));
}catch(IOException e)
{
e.printStackTrace();
}
}
}
You didn't define the function String toString() in your class CountPerDocument. So, when you try to print a CountPerDocument variable, the default printed value is CountPerDocument#hashcode.
To decide how to represent a CountPerDocument variable in your code, add in your class the next function:
#Override
public String toString() {
return "<" + this.getDocumentId() + ", " + this.getCount() + ">";
}
Try to override toString method in CountPerDocument. Something like this:
public class CountPerDocument
{
private final String documentId;
private final int count;
CountPerDocument(String documentId, int count)
{
this.documentId = documentId;
this.count = count;
}
public String getDocumentId()
{
return this.documentId;
}
public int getCount()
{
return this.count;
}
#Override
public String toString() {
return documentId + "-" + count;
}
}

How to increment the filename number if the file exists

How can I increment the filename if the file already exists?
Here's the code that I am using -
int num = 0;
String save = at.getText().toString() + ".jpg";
File file = new File(myDir, save);
if (file.exists()) {
save = at.getText().toString() + num + ".jpg";
file = new File(myDir, save);
num++;
}
This code works, but only two files are saved, like file.jpg and file2.jpg.
This problem is to always initialize num = 0, so if file exists, it saves file0.jpg and does not check whether file0.jpg exists.
So, to code work. You should check until it is available:
int num = 0;
String save = at.getText().toString() + ".jpg";
File file = new File(myDir, save);
while(file.exists()) {
save = at.getText().toString() + (num++) + ".jpg";
file = new File(myDir, save);
}
Try this:
File file = new File(myDir, at.getText().toString() + ".jpg");
for (int num = 0; file.exists(); num++) {
file = new File(myDir, at.getText().toString() + num + ".jpg");
}
// Now save/use your file here
In addition to the first answer, I made some more changes:
private File getUniqueFileName(String folderName, String searchedFilename) {
int num = 1;
String extension = getExtension(searchedFilename);
String filename = searchedFilename.substring(0, searchedFilename.lastIndexOf("."));
File file = new File(folderName, searchedFilename);
while (file.exists()) {
searchedFilename = filename + "(" + (num++) + ")" + extension;
file = new File(folderName, searchedFilename);
}
return file;
}
int i = 0;
String save = at.getText().toString();
String filename = save +".jpg";
File f = new File(filename);
while (f.exists()) {
i++;
filename =save+ Integer.toString(i)+".jpg";
f = new File(filename);
}
f.createNewFile();
You can avoid the code repetition of some of the answers here by using a do while loop
Here's an example using the newer NIO Path API introduced in Java 7
Path candidate = null;
int counter = 0;
do {
candidate = Paths.get(String.format("%s-%d",
path.toString(), ++counter));
} while (Files.exists(candidate));
Files.createFile(candidate);
Kotlin version:
private fun checkAndRenameIfExists(name: String): File {
var filename = name
val extension = "pdf"
val root = Environment.getExternalStorageDirectory().absolutePath
var file = File(root, "$filename.$extension")
var n = 0
while (file.exists()) {
n += 1
filename = "$name($n)"
file = File(root, appDirectoryName + File.separator + "$filename.$extension")
}
return file
}
Another simple logic solution to get the unique file name under a directory using Apache Commons IO using WildcardFileFilter to match the file name and get the number of exists with the given name and increment the counter.
public static String getUniqueFileName(String directory, String fileName) {
String fName = fileName.substring(0, fileName.lastIndexOf("."));
Collection<File> listFiles = FileUtils.listFiles(new File(directory), new WildcardFileFilter(fName + "*", IOCase.INSENSITIVE), DirectoryFileFilter.DIRECTORY);
if(listFiles.isEmpty()) {
return fName;
}
return fName.concat(" (" + listFiles.size() + ")");
}
This is the solution I use to handle this case. It works for folders as well as for files.
var destination = File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), "MyFolder")
if (!destination.exists()) {
destination.mkdirs()
} else {
val numberOfFileAlreadyExist =
destination.listFiles().filter { it.name.startsWith("MyFolder") }.size
destination = File(
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS),
"MyFolder(${numberOfFileAlreadyExist + 1})"
)
destination.mkdirs()
}
Having needed to solve this problem in my own code, I took Tejas Trivedi's answer, made it work like Windows when you happen to download the same file several times.
// This function will iteratively to find a unique file name to use when given a file: example (###).txt
// More or less how Windows will save a new file when one already exists: 'example.txt' becomes 'example (1).txt'.
// if example.txt already exists
private File getUniqueFileName(File file) {
File originalFile = file;
try {
while (file.exists()) {
String newFileName = file.getName();
String baseName = newFileName.substring(0, newFileName.lastIndexOf("."));
String extension = getExtension(newFileName);
Pattern pattern = Pattern.compile("( \\(\\d+\\))\\."); // Find ' (###).' in the file name, if it exists
Matcher matcher = pattern.matcher(newFileName);
String strDigits = "";
if (matcher.find()) {
baseName = baseName.substring(0, matcher.start(0)); // Remove the (###)
strDigits = matcher.group(0); // Grab the ### we'll want to increment
strDigits = strDigits.substring(strDigits.indexOf("(") + 1, strDigits.lastIndexOf(")")); // Strip off the ' (' and ').' from the match
// Increment the found digit and convert it back to a string
int count = Integer.parseInt(strDigits);
strDigits = Integer.toString(count + 1);
} else {
strDigits = "1"; // If there is no (###) match then start with 1
}
file = new File(file.getParent() + "/" + baseName + " (" + strDigits + ")" + extension); // Put the pieces back together
}
return file;
} catch (Error e) {
return originalFile; // Just overwrite the original file at this point...
}
}
private String getExtension(String name) {
return name.substring(name.lastIndexOf("."));
}
Calling getUniqueFileName(new File('/dir/example.txt') when 'example.txt' already exists while generate a new File targeting '/dir/example (1).txt' if that too exists it'll just keep incrementing number between the parentheses until a unique file is found, if an error happens, it'll just give the original file name.
I hope this helps some one needing to generate a unique file in Java on Android or another platform.
This function returns the exact new file with an increment number for all kind of extensions.
private File getFileName(File file) {
if (file.exists()) {
String newFileName = file.getName();
String simpleName = file.getName().substring(0, newFileName.indexOf("."));
String strDigit = "";
try {
simpleName = (Integer.parseInt(simpleName) + 1 + "");
File newFile = new File(file.getParent() + "/" + simpleName + getExtension(file.getName()));
return getFileName(newFile);
}
catch (Exception e){
}
for (int i=simpleName.length()-1; i>=0; i--) {
if (!Character.isDigit(simpleName.charAt(i))) {
strDigit = simpleName.substring(i + 1);
simpleName = simpleName.substring(0, i+1);
break;
}
}
if (strDigit.length() > 0) {
simpleName = simpleName + (Integer.parseInt(strDigit) + 1);
}
else {
simpleName += "1";
}
File newFile = new File(file.getParent() + "/" + simpleName + getExtension(file.getName()));
return getFileName(newFile);
}
return file;
}
private String getExtension(String name) {
return name.substring(name.lastIndexOf("."));
}

Java - renaming output file if name already exists with an increment, taking into account existing increments

building an Android app i came across the need to do some file copying. I would like a way to get new filenames in the event of a filename allready being used by adding a "(increment)" string in the filename. for example
text.txt ---> text(1).txt
The algorith should account for the following
1) if text.txt exists the new file name should NEVER be text.txt(1)
2) if text(1).txt exists then new filename should be text(2).txt not text(1)(1).txt
3) if text(1)foo.txt exists the new filename should be text(1)foo(1).txt
I've allready done the first but I'm having difficulties with the second. Regular expressions is not my strong suit!(It's not mandatory to use Regex. every approach is welcome) Some help ?
ANSWER:
combining my original code and one of the answers here I ended up with this which works very well for me in all cases regardless of file having an extension or not:
public static File getFinalNewDestinationFile(File destinationFolder, File fileToCopy){
String destFolderPath = destinationFolder.getAbsolutePath()+File.separator;
File newFile = new File(destFolderPath + fileToCopy.getName());
String filename=fileToCopy.getName();
String nameWithoutExtentionOrIncrement;
String extension = getFileExtension(filename);
if(extension!=null){
extension="."+extension;
int extInd = filename.lastIndexOf(extension);
nameWithoutExtentionOrIncrement = new StringBuilder(filename).replace(extInd, extInd+extension.length(),"").toString();
}
else{
extension="";
nameWithoutExtentionOrIncrement = filename;
}
int c=0;
int indexOfClose = nameWithoutExtentionOrIncrement.lastIndexOf(")");
int indexOfOpen = nameWithoutExtentionOrIncrement.lastIndexOf("(");
if(indexOfClose!=-1 && indexOfClose!=-1 && indexOfClose==nameWithoutExtentionOrIncrement.length()-1 && indexOfClose > indexOfOpen && indexOfOpen!=0){
String possibleNumber = nameWithoutExtentionOrIncrement.substring(indexOfOpen+1, indexOfClose);
try{
c = Integer.parseInt(possibleNumber);
nameWithoutExtentionOrIncrement=nameWithoutExtentionOrIncrement.substring(0, indexOfOpen);
}catch(Exception e){c=0;}
}
while(newFile.exists()){
c++;
String path = destFolderPath + nameWithoutExtentionOrIncrement +"(" + Integer.toString(c) + ")" + extension;
newFile = new File(path);
}
return newFile;
}
public static String getFileExtension(String filename) {
if (filename == null) { return null; }
int lastUnixPos = filename.lastIndexOf('/');
int lastWindowsPos = filename.lastIndexOf('\\');
int indexOfLastSeparator = Math.max(lastUnixPos, lastWindowsPos);
int extensionPos = filename.lastIndexOf('.');
int lastSeparator = indexOfLastSeparator;
int indexOfExtension = lastSeparator > extensionPos ? -1 : extensionPos;
int index = indexOfExtension;
if (index == -1) {
return null;
} else {
return filename.substring(index + 1).toLowerCase();
}
}
Using one regex pattern:
final static Pattern PATTERN = Pattern.compile("(.*?)(?:\\((\\d+)\\))?(\\.[^.]*)?");
String getNewName(String filename) {
if (fileExists(filename)) {
Matcher m = PATTERN.matcher(filename);
if (m.matches()) {
String prefix = m.group(1);
String last = m.group(2);
String suffix = m.group(3);
if (suffix == null) suffix = "";
int count = last != null ? Integer.parseInt(last) : 0;
do {
count++;
filename = prefix + "(" + count + ")" + suffix;
} while (fileExists(filename));
}
}
return filename;
}
The regex pattern explanation:
(.*?) a non greedy "match everything" starting at the beginning
(?:\\((\\d+)\\))? a number in parenthesis (optional)
(?:____________) - is a non capturing group
___\\(______\\)_ - matches ( and )
______(\\d+)____ - matches and captures the one or more digits
(\\.[^.]+)? a dot followed by anything but a dot (optional)
Here's one way of doing it:
String fileName;
File file = new File(fileName);
if(file.exists()) {
int dot = fileName.lastIndexOf('.'), open = fileName.lastIndexOf('('), incr;
boolean validNum = false;
if(fileName.charAt(dot-1) == ')' && open != -1){
String n = fileName.substring(open+1, dot-1);
try {
incr = Integer.parseInt(n);
validNum = true;
} catch(NumberFormatException e) {
validNum = false;
}
}
if(validNum) {
String pre = fileName.substring(0, open+1), post = fileName.substring(0, dot-1);
while(new File(pre + ++incr + post).exists());
fileName = pre + incr + post;
} else {
fileName = fileName.substring(0, dot) + "(1)" + fileName.substring(dot);
}
}
I assume a couple of things:
1) A method called fileExists(String fileName) is available. It returns true if a file with the specified name is already present in the file system.
2) There is a constant called FILE_NAME which in your example case is equal to "text".
if (!fileExists(FILE_NAME)) {
//create file with FILE_NAME.txt as name
}
int availableIndex = 1;
while (true) {
if (!fileExists(currentName)) {
//create file with FILE_NAME(availableIndex).txt
break;
}
availableIndex++;
}
I am not very sure about Android but since its a Java program, you may be able to create File object of the directory in which you want to write.
Once you have this you can see the list of file names already present inside it and other related information. Then you can decide the file name as per your above logic.
File dir = new File("<dir-path>");
if(dir.isDirectory()){
String[] files = dir.list();
for(String fileName : files){
<logic for finding filename>
}
}
If all filenames have an extenstion you could do something like this (just an example you will have to change it to work in your case):
public static void main(String[] args)
{
String test = "test(1)foo.txt";
String test1 = "test(1)foo(1).txt";
Pattern pattern = Pattern.compile("((?<=\\()\\d+(?=\\)\\.))");
Matcher matcher = pattern.matcher(test);
String fileOutput = "";
String temp = null;
int newInt = -1;
while(matcher.find())
{
temp = matcher.group(0);
}
if(temp != null)
{
newInt = Integer.parseInt(temp);
newInt++;
fileOutput = test.replaceAll("\\(\\d+\\)(?=\\.(?!.*\\.))", "(" + newInt + ")");
}
else
{
fileOutput = test;
}
System.out.println(fileOutput);
matcher = pattern.matcher(test1);
fileOutput = "";
temp = null;
while(matcher.find())
{
temp = matcher.group(0);
}
if(temp != null)
{
newInt = Integer.parseInt(temp);
newInt++;
fileOutput = test1.replaceAll("\\(\\d+\\)(?=\\.(?!.*\\.))", "(" + newInt + ")");
}
else
{
fileOutput = test1;
}
System.out.println(fileOutput);
}
Output:
test(1)foo.txt
test(1)foo(2).txt
This uses regex to look for a number in the () right before the last ..
Update
replaceAll() changed to handle case where there is a . after the first (1) in test(1).foo(1).txt.

How to parse a String into multiple arrays

Good day!
I am making a mini bookstore program and we are required to read a file based from what the customer buys on the specified counter as follows:
counter 4,book1 2,book2 2,book3 2,tender 100.00
counter 1,book1 2,book2 1,book3 3, book4 5,tender 200.00
counter 1,book3 1,tender 50.00
In short the format is:
COUNTER -> ITEMS BOUGHT -> TENDER
I tried doing this but it is not that efficient:
public List<String> getOrder(int i) {
List <String> tempQty = new ArrayList<String>();
String[] orders = orderList.get(0).split(",");
for (String order : orders) {
String[] fields = order.split(" ");
tempQty.add(fields[i]);
}
return tempQty;
}
How can i read the file and at the same time, ensures that I will put it on the correct array? Besides the counter and the tender, I need to know the name of the book and the qty so I could get its price and computer for the total price. Do I need to do multiple arrays to store each values? Any suggestions/ codes will be
highly appreciated.
Thank you.
Map<String, Integer> itemsBought = new HashMap<String, Integer>();
final String COUNTER = "counter";
final String TENDER = "tender";
String[] splitted = s.split(",");
for (String str : splitted) {
str = str.trim();
if (str.startsWith(COUNTER)) {
//do what you want with counter
} else if (str.startsWith(TENDER)) {
//do what you want with tender
} else {
//process items, e.g:
String[] itemInfo = str.split(" ");
itemsBought.put(itemInfo[0], Integer.valueOf(itemInfo[1]));
}
}
How about this? Here we have a class that is modeling a purchase, containing counter, tender and a list of the bought items. The bought item consists of an id (e.g. book1) and a quantity. Use the method readPurchases() to read the contents of a file and get a list of purchases.
Does this solve your problem?
public class Purchase {
private final int counter;
private final List<BoughtItem> boughtItems;
private final double tender;
public Purchase(int counter, List<BoughtItem> boughtItems, double tender) {
this.counter = counter;
this.boughtItems = new ArrayList<BoughtItem>(boughtItems);
this.tender = tender;
}
public int getCounter() {
return counter;
}
public List<BoughtItem> getBoughtItems() {
return boughtItems;
}
public double getTender() {
return tender;
}
}
public class BoughtItem {
private final String id;
private final int quantity;
public BoughtItem(String id, int quantity) {
this.id = id;
this.quantity = quantity;
}
public String getId() {
return id;
}
public int getQuantity() {
return quantity;
}
}
public class Bookstore {
/**
* Reads purchases from the given file.
*
* #param file The file to read from, never <code>null</code>.
* #return A list of all purchases in the file. If there are no
* purchases in the file, i.e. the file is empty, an empty list
* is returned
* #throws IOException If the file cannot be read or does not contain
* correct data.
*/
public List<Purchase> readPurchases(File file) throws IOException {
List<Purchase> purchases = new ArrayList<Purchase>();
BufferedReader lines = new BufferedReader(new FileReader(file));
String line;
for (int lineNum = 0; (line = lines.readLine()) != null; lineNum++) {
String[] fields = line.split(",");
if (fields.length < 2) {
throw new IOException("Line " + lineNum + " of file " + file + " has wrong number of fields");
}
// Read counter field
int counter;
try {
String counterField = fields[0];
counter = Integer.parseInt(counterField.substring(counterField.indexOf(' ') + 1));
} catch (Exception ex) {
throw new IOException("Counter field on line " + lineNum + " of file " + file + " corrupt");
}
// Read tender field
double tender;
try {
String tenderField = fields[fields.length - 1];
tender = Double.parseDouble(tenderField.substring(tenderField.indexOf(' ') + 1));
} catch (Exception ex) {
throw new IOException("Tender field on line " + lineNum + " of file " + file + " corrupt");
}
// Read bought items
List<BoughtItem> boughtItems = new ArrayList<BoughtItem>();
for (int i = 1; i < fields.length - 1; i++) {
String id;
int quantity;
try {
String bookField = fields[i];
id = bookField.substring(0, bookField.indexOf(' '));
quantity = Integer.parseInt(bookField.substring(bookField.indexOf(' ') + 1));
BoughtItem boughtItem = new BoughtItem(id, quantity);
boughtItems.add(boughtItem);
} catch (Exception ex) {
throw new IOException("Cannot read items from line " + lineNum + " of file " + file);
}
}
// We're done with this line!
Purchase purchase = new Purchase(counter, boughtItems, tender);
purchases.add(purchase);
}
return purchases;
}
}

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