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How to find out which file caused the exception?

I am using FileReader wrapped in BufferedReader to read from 2 files, in case of an exception being thrown I want to know which file caused the error.
Is there a way of finding that out?
try (BufferedReader input1 = new BufferedReader(new FileReader(pathToFile1));
BufferedReader input2 = new BufferedReader(new FileReader(pathToFile2))){
// some more code here
} catch (FileNotFoundException e) {
System.err.println("File Not Found");
System.err.println(e.getMessage());
System.exit(2);
} catch (IOException e) {
System.err.println(e.getMessage());
System.exit(1);
Basically I want to know which file was not found and caused the first exception to be thrown.

Though I wouldn't recommend it (as it depends on linenumbers which might change if run through a preprocessor) You could use something like this
int topLine= new Throwable().getStackTrace()[0].getLineNumber();
try (BufferedReader input1 = new BufferedReader(new FileReader("pop"));
BufferedReader input2 = new BufferedReader(new FileReader("poo"))){
// some more code here
} catch (Exception e) {
StackTraceElement[] er= e.getStackTrace();
int exceptLine = er[er.length-1].getLineNumber() - topLine;
if (exceptLine==1) {
// error in first buffered reader
} else if (exceptLine==2) {
// error in second buffered reader
} else {
// error elsewhere
}
}

Get last element of an array

through an API I get an array with a lot of different data. But I only need the last element.
The variable sb has the array in it. But i cannot access elements like that: sb[0] (for example)
If I print the variable sb it looks like that:
{"data":[[[1583596801195,279.52],[1583596814340,279.52],[1583596815535,279.44563849372383],[1583596816730,279.2060000000001],[1583596913525,279.2060000000001],[1583596914720,279.28824435146447],[1583596915915,279.52],[1583597211080,279.52],[1583597212275,279.52000000000004],[1583597213470,279.52],[1583597609015,279.52],[1583597610210,279.5199999999999],[1583597707005,279.5199999999999],[1583597708200,279.52000000000004],[1583597709395,279.52],[1583597806190,279.52],[1583597807385,279.52000000000004],[1583597993805,279.52000000000004]]]}
In this case, I only need the last element (279.52000000000004).
My code look like that:
URL url = new URL("the URL i get the data from");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("GET");
InputStream instream = con.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(instream));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
instream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
System.out.println(sb);
Sorry I am not experienced that experienced with programming. But I would really appreciate if someone could help me.
Thank you for your help.

If you need the last element only, you should not be appending the results.
Instead, replace the previous value stored.
String result = null;
String line = null;
try {
while ((line = reader.readLine()) != null) {
//sb.append(line + "\n");
result = line; // not appending, but replacing
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
instream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
System.out.println(result);

You can try this, replace this line "System.out.println(sb) with below code :
String s = new String(sb);
String d[] = s.split(",");
System.out.println(d[d.length -1].replaceAll("]", ""));
This would print the exact data you want i.e 279.52000000000004

ReplaceAll not working on XML input

I am working on a java program that reads in XML and generates an output XML. I am having a problem replacing some of the characters in my read in file.
The following is my method:
public void readTemplateXML() {
BufferedReader br = null;
try {
br = new BufferedReader(new InputStreamReader(new FileInputStream(
path), "UTF8"));
} catch (UnsupportedEncodingException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
String line;
StringBuilder sb = new StringBuilder();
try {
while ((line = br.readLine()) != null) {
sb.append(line);
sb.append(System.lineSeparator());
line = br.readLine();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
xml = sb.toString();
xml = xml.replaceAll("<", "\\<"); //This is not working.
}
I am just outputting the "xml" string to an xml file and I am still getting "<":
<addressLine1>Main Street</addressLine1>
Is there anyway I can replace these characters with <, > ?
The encoding of the file is UTF-8.
EDIT:
the xml string is correct after the replace alls. I am using it as text content in another methods xml node:
// inner request element
Element request = doc.createElement("con:request");
request.appendChild(doc.createTextNode(xml));
rootElement.appendChild(request);
After this the content is incorrect.
Any help would be greatly appreaciated.

short answer :
Syntax:
Here is the syntax of this method:
public String replaceAll(String regex, String replacement)
Parameters:
Here is the detail of parameters:
regex -- the regular expression to which this string is to be matched.
replacement -- the string which would replace found expression.
code :
String xml="<addressLine1>Main Street</addressLine1>&#13";
xml = xml.replaceAll("<", "\\<");
xml = xml.replaceAll(">", "\\>");
xml = xml.replaceAll("&#13", "");
System.out.println( xml );
result :
<addressLine1>Main Street</addressLine1>

Reading from a text file with spaces and then putting into arrayList

I have spent the last week trying to figure out how to make this stupid code work. I have managed to get everything to work except for reading from my text file. It can read an individual integer on a line, but when given a line with multiple integers separated by spaces, it freaks out. Now I've gone and tried to fix it and the code won't even compile anymore. Only one line is causing problems.
I'm not good at coding, so I don't know where to begin. Yes, I've looked this up online. Yes, I've checked the forums. Yes, I have tried multiple different methods to make this work....
How do I fix this?? :(
ArrayList<Integer> list = new ArrayList<Integer>();
// the above line is in a different method in the same class, but it's relevant here
File file = new File("C:\\Users\\Jocelynn\\Desktop\\input.txt");
BufferedReader reader = null;
try
{
reader = new BufferedReader(new FileReader(file));
String text = null;
while ((text = reader.readLine()) != null)
{
// I want the following line to read "218 150 500 330", and to store each individual integer into the list. I don't know why it won't work :(
list.add(Integer.parseInt(src.next().trim()));
}
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
try
{
reader.close();
}
catch (IOException e)
{
e.printStackTrace();
}
//print out the list
System.out.println(list);
Thank you for the help! I'm sure that I'm just missing something really simple...

You can use a Scanner(String) like
while ((text = reader.readLine()) != null) {
Scanner scanner = new Scanner(text);
while (scanner.hasNextInt()) {
list.add(scanner.nextInt());
}
}
Of course, your entire method could be simplified by using a try-with-resources Statement and the diamond operator and just Scanner(File) like
public static void main(String[] args) {
File file = new File("C:\\Users\\Jocelynn\\Desktop\\input.txt");
List<Integer> list = new ArrayList<>();
try (Scanner scanner = new Scanner(file);) {
while (scanner.hasNextInt()) {
list.add(scanner.nextInt());
}
} catch (Exception e) {
e.printStackTrace();
}
// print out the list
System.out.println(list);
}

Do this inside the while loop
String[] individualArray = text.split(" ");//note space
for(String individual:individualArray){
yourList.add(individual);//You need to parse it to integer here as you have already done
}
In the above code, individualArray will contain each individual integers that are separated by space. And inside the for loop each string needs to be parsed to integer and then added to your list

try this :
public static void main(String[] args) {
ArrayList<Integer> list = new ArrayList<Integer>();
File file = new File("C:\\Users\\Jocelynn\\Desktop\\input.txt");
BufferedReader reader = null;
try
{
reader = new BufferedReader(new FileReader(file));
String text = null;
while ((text = reader.readLine()) != null)
{
// you need only this for loop in you code.
for (String value : text.split(" ")) { // get list of integer
if(!value.equals("")) // ignore space
list.add(Integer.parseInt(value)); // add to list
}
}
} catch (FileNotFoundException e)
{
e.printStackTrace();
} catch (IOException e)
{
e.printStackTrace();
}
try
{
reader.close();
} catch (IOException e)
{
e.printStackTrace();
}
// print out the list
System.out.println(list);
}

Issue with Converting XML file into single String

I am creating an XML file from my Database and storing it in Internal storage. I require data from XML file into a single string. For which, i am using the following method.
BufferedReader br;
try {
br = new BufferedReader(new FileReader(new File(pathDAR)));
String line;
StringBuilder sb = new StringBuilder();
while ((line = br.readLine()) != null) {
sb.append(line.trim());
String temp = sb.toString().substring(38);
Log.v("XML TO String", "" + temp);
Log.v("Lengths : ", "" + temp.length() + " " + sb.length());
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
I have been getting string in the Log, but it seems to be stopping abruptly in the middle.
For e.g. I am supposed to get records string like this. Beginning and ending with database tag.
<database name="DAR.db"><table name="DARWorkDetails"><row><col name="id">1</col><col name="date">05-28-2013</col><col name="visited_city_ID">1264</col><col name="employee_ID">107</col><col name="work_type_ID">1</col><col name="name">null</col><col name="customer_Id">null</col><col name="customer_type_ID">null</col><col name="sub_customer_id">null</col><col name="reason_ID">14</col><col name="reason">ABM SM MEETING</col><col name="remarks">gfhii</col><col name="work_with">211,162</col><col name="IsCustomer">N</col><col name="created_by">107</col><col name="position_id">72</col><col name="designation_Id">3</col><col name="submit_date">05-28-2013</col><col name="IsFinal">null</col></row></table></database>
Instead i have been getting string like this :
<database name="DAR.db"><table name="DARWorkDetails"><row><col name="id">1</col><col name="date">05-28-2013</col><col name="visited_city_ID">1264</col><col name="employee_ID">107</col><col name="work_type_ID">1</col><col name="name">null</col><col name="customer_Id">null</col><col name="customer_type_ID">null</col><col name="sub_customer_id">null</col><col name="reason_ID">14</col><col name="reason">ABM SM MEETING</col><col name="remarks">gfhii</col><col name="work_with">211,162</col><col name="IsCustomer">N</col><col name="created_by">107</col><col name="position_id">72</col><col name="designation_Id">3</col><col name="submit_date">05-28-2013</col><col name="IsFinal">null</co
The String is stopping in the middle. For the sake of example i have only put small example string above. In reality my database has multiple records and i have counted length of the string to around 15640, before abrupt end of the string.
Are there any limitations with StringBuilder in regards to storing characters? I suppose there is memory issue since i have been able to get string fully for records fewer than 10. Problem seems to be arising when records go into upwards of 10. Any help in understanding of solving this issue would be much appreciated.

Please check
It may happen your output is perfect but your Log cat is not displaying it whole.
Log.v("XML TO String", "" + temp);
Log.v("Lengths : ", "" + temp.length() + " " + sb.length());
See reference

I created this class to read strings from a xml file saved in internal storage device, it returns a list , if you want the whole extended string you only need concatenate to link together, if doesn't found the file return an empty list this is all you need to read XML files and parse to Strings, I hope to help!
public class readXMLFile {
private String filePath = "FileStorage";
private String fileName = "File.xml";
private final String tag = "Internal Read Persistence";
File internalFileData;
public readXMLFile() {// default constructor
}
public File getXMLFile(Context context){
File directory = null;
ContextWrapper cw = new ContextWrapper(context);
directory = cw.getDir(filePath, Context.MODE_PRIVATE);
internalFileData = new File(directory, fileName);
if(internalFileData.exists()){
Log.i("ReadXMLFile","File returned");
return internalFileData;
}
else{
Log.i(tag,"the file doesn't exists!");
return null;
}
}
public List<String> readFile(Context context) {
List<String> l = new LinkedList<String>();
try {
File directory = null;
ContextWrapper cw = new ContextWrapper(context);
directory = cw.getDir(filePath, Context.MODE_PRIVATE);
internalFileData = new File(directory, fileName);
if (internalFileData.exists()) {
Log.i("Internal Data", "the root exists!!");
try {
FileInputStream fis = new FileInputStream(internalFileData);
DataInputStream in = new DataInputStream(fis);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String line;
while ((line = br.readLine()) != null) {
l.add(line);
}
try {
if (in != null) {
in.close();
}
} catch (Exception e) {
Log.i(tag, "Exception closing persistence connection");
}
} catch (Exception e) {
Log.wtf("Fatal Exception", "Exception: " + e.getMessage());
}
} else {
Log.i(tag, "File doesn't exists");
return l;//return empty list
}
} catch (Exception e) {
Log.wtf(tag, "Exception DATA READING: " + e.getMessage());
return l;
}
Log.i(tag, "file found return");
return l;
}
}