Develop Reference

Java read specific parts of a CSV

I created the following code to read a CSV-file:
public void read(String csvFile) {
try {
File file = new File(csvFile);
FileReader fr = new FileReader(file);
BufferedReader br = new BufferedReader(fr);
String line = "";
String[] tempArr;
while((line = br.readLine()) != null) {
tempArr = line.split(ABSTAND);
anzahl++;
for(String tempStr : tempArr) {
System.out.print(tempStr + " ");
}
System.out.println();
}
br.close();
} catch(IOException ioe) {
ioe.printStackTrace();
}
}
I have a CSV with more than 300'000 lines that look like that:
{9149F314-862B-4DBC-B291-05A083658D69};Gebaeude;TLM_GEBAEUDE;;Schiessstand;{41C949A2-9F7B-41EE-93FD-631B76F2176D};Altdorf 300m;offiziell;Hochdeutsch inkl. Lokalsprachen;Einfacher Name;;684600;295930;400
How can I now only get the some parts out of that? I only need the bold/italic parts to work with.

Without further specifying what your requirements/input limitations are the following should work within your loop.
String str = "{9149F314-862B-4DBC-B291-05A083658D69};Gebaeude;TLM_GEBAEUDE;;Schiessstand;{41C949A2-9F7B-41EE-93FD-631B76F2176D};Altdorf 300m;offiziell;Hochdeutsch inkl. Lokalsprachen;Einfacher Name;;684600;295930;400";
String[] arr = str.split("[; ]", -1);
int cnt=0;
// for (String a : arr)
// System.out.println(cnt++ + ": " + a);
System.out.println(arr[6] + ", " + arr[15] + ", " + arr[16]);
Note that this assumes your delimiters are either a semicolon or a space and that the fields desired are in the fix positions (6, 15, 16).
Result:
Altdorf, 684600, 295930

Search for multiline String in a text file

I have a text file from which i am trying to search for a String which has multiple lines. A single string i am able to search but i need multi line string to be searched.
I have tried to search for single line which is working fine.
public static void main(String[] args) throws IOException
{
File f1=new File("D:\\Test\\test.txt");
String[] words=null;
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String s;
String input="line one";
// here i want to search for multilines as single string like
// String input ="line one"+
// "line two";
int count=0;
while((s=br.readLine())!=null)
{
words=s.split("\n");
for (String word : words)
{
if (word.equals(input))
{
count++;
}
}
}
if(count!=0)
{
System.out.println("The given String "+input+ " is present for "+count+ " times ");
}
else
{
System.out.println("The given word is not present in the file");
}
fr.close();
}
And below are the file contents.
line one
line two
line three
line four

Use the StringBuilder for that, read every line from file and append them to StringBuilder with lineSeparator
StringBuilder lineInFile = new StringBuilder();
while((s=br.readLine()) != null){
lineInFile.append(s).append(System.lineSeparator());
}
Now check the searchString in lineInFile by using contains
StringBuilder searchString = new StringBuilder();
builder1.append("line one");
builder1.append(System.lineSeparator());
builder1.append("line two");
System.out.println(lineInFile.toString().contains(searchString));

More complicated solution from default C (code is based on code from book «The C programming language» )
final String searchFor = "Ich reiß der Puppe den Kopf ab\n" +
"Ja, ich reiß' ich der Puppe den Kopf ab";
int found = 0;
try {
String fileContent = new String(Files.readAllBytes(
new File("puppe-text").toPath()
));
int i, j, k;
for (i = 0; i < fileContent.length(); i++) {
for (k = i, j = 0; (fileContent.charAt(k++) == searchFor.charAt(j++)) && (j < searchFor.length());) {
// nothig
}
if (j == searchFor.length()) {
++found;
}
}
} catch (IOException ignore) {}
System.out.println(found);

Why don't you just normalize all the lines in the file to one string variable and then just count the number of occurrences of the input in the file. I have used Regex to count the occurrences but can be done in any custom way you find suitable.
public static void main(String[] args) throws IOException
{
File f1=new File("test.txt");
String[] words=null;
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String s;
String input="line one line two";
// here i want to search for multilines as single string like
// String input ="line one"+
// "line two";
int count=0;
String fileStr = "";
while((s=br.readLine())!=null)
{
// Normalizing the whole file to be stored in one single variable
fileStr += s + " ";
}
// Now count the occurences
Pattern p = Pattern.compile(input);
Matcher m = p.matcher(fileStr);
while (m.find()) {
count++;
}
System.out.println(count);
fr.close();
}
Use StringBuilder class for efficient string concatenation.

Try with Scanner.findWithinHorizon()
String pathToFile = "/home/user/lines.txt";
String s1 = "line two";
String s2 = "line three";
String pattern = String.join(System.lineSeparator(), s1, s2);
int count = 0;
try (Scanner scanner = new Scanner(new FileInputStream(pathToFile))) {
while (scanner.hasNext()) {
String withinHorizon = scanner.findWithinHorizon(pattern, pattern.length());
if (withinHorizon != null) {
count++;
} else {
scanner.nextLine();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
System.out.println(count);

Try This,
public static void main(String[] args) throws IOException {
File f1 = new File("./src/test/test.txt");
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String input = "line one";
int count = 0;
String line;
while ((line = br.readLine()) != null) {
if (line.contains(input)) {
count++;
}
}
if (count != 0) {
System.out.println("The given String " + input + " is present for " + count + " times ");
} else {
System.out.println("The given word is not present in the file");
}
fr.close();
}

Trying to concatenate a series of strings via array

having a little bit of an issue. I am looping through a file where by I want to filter out a series of texts and concatenate them at the end of each loop, which then ultimately end up ordering i.e. during the loop phase it does the following:
String A = "A /n"
String A = "A /n U /n"
String A = "A /n U /n B /n"
etc...
The output will be
A
U
B
however i want it to be
A
B
U
I have so far done the following:
public static void organiseFile() throws FileNotFoundException {
ArrayList<String> lines = new ArrayList<>();
ArrayList<String> order = new ArrayList<>();
String directory = "C:\\Users\\xxx\\Desktop\\Files\\ex1";
Scanner fileIn = new Scanner(new File(directory + "_ordered.txt"));
PrintWriter out = new PrintWriter(directory + "_orderesqsd.txt");
String otherStates = "";
while (fileIn.hasNextLine() == true) {
lines.add(fileIn.nextLine());
System.out.println("Organising...");
}
Collections.sort(lines);
for (String output : lines) {
if (output.contains("[EVENT=agentStateEvent]")) {
out.println(output + "\n");
out.println(otherStates + "\n");
otherStates = "";
}
else {
otherStates += output+ "\n";
}
out.close();
}
Now this does output fine, however, with regards to the "otherStates", i want to get this in a numeric order, and the best way I know is using Collections, however this is for arrays. I am unsure how to go about modifying the "otherStates" part of the code to cater for an array that concatanetates the string and then be able to order them accordingly. Any ideas

Hard to give a correct solution without input file data . Just try the below code. At the very least it should give you some ideas on how to solve the issue
public static void organiseFile() throws FileNotFoundException {
ArrayList<String> lines = new ArrayList<>();
ArrayList<String> order = new ArrayList<>();
String directory = "C:\\Users\\xxx\\Desktop\\Files\\ex1";
Scanner fileIn = new Scanner(new File(directory + "_ordered.txt"));
PrintWriter out = new PrintWriter(directory + "_orderesqsd.txt");
String otherStates = "";
ArrayList<String> otherStates_duplicate = new ArrayList<>();
String ordered_new_string.;
while (fileIn.hasNextLine() == true) {
lines.add(fileIn.nextLine());
System.out.println("Organising...");
}
Collections.sort(lines);
for (String output : lines) {
if (output.contains("[EVENT=agentStateEvent]")) {
out.println(output + "\n");
out.println(otherStates + "\n");
otherStates = "";
}
else {
otherStates += output+ "\n";
otherStates_duplicate.add(output);
}
Collections.sort(otherStates_duplicate); // Now this should have a sorted list
//if you need a string instead of an arraylist use code below in addition
for(String s:otherStates_duplicate){
ordered_new_string += s + "\n";
}
/*
I have not printed or stored the string ordered_new_string as it is not
clear to me what you want. print/write to a file and check
if ordered_new_string is what your required
*/
out.close();
}

usage of stringtokenizer in java to display selected contents from a file

Can any one suggest, how to use string-tokens in java, to read all data in a file, and display only some of its contents. Like, if i have
apple = 23456, mango = 12345, orange= 76548, guava = 56734
I need to select apple, and the value corresponding to apple should be displayed in the output.
This is the code
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.StringTokenizer;
public class ReadFile {
public static void main(String[] args) {
try {
String csvFile = "Data.txt";
//create BufferedReader to read csv file
BufferedReader br = new BufferedReader(new FileReader(csvFile));
String line = "";
StringTokenizer st = null;
int lineNumber = 0;
int tokenNumber = 0;
//read comma separated file line by line
while ((line = br.readLine()) != null) {
lineNumber++;
//use comma as token separator
st = new StringTokenizer(line, ",");
while (st.hasMoreTokens()) {
tokenNumber++;
//display csv values
System.out.print(st.nextToken() + " ");
}
System.out.println();
//reset token number
tokenNumber = 0;
}
} catch (Exception e) {
System.err.println("CSV file cannot be read : " + e);
}
}
}
this is the file I'm working on :
ImageFormat=GeoTIFF
ProcessingLevel=GEO
ResampCode=CC
NoScans=10496
NoPixels=10944
MapProjection=UTM
Ellipsoid=WGS_84
Datum=WGS_84
MapOriginLat=0.00000000
MapOriginLon=0.00000000
ProdULLat=18.54590200
ProdULLon=73.80059300
ProdURLat=18.54653200
ProdURLon=73.90427600
ProdLRLat=18.45168500
ProdLRLon=73.90487900
ProdLLLat=18.45105900
ProdLLLon=73.80125300
ProdULMapX=373416.66169100
ProdULMapY=2051005.23286800
ProdURMapX=384360.66169100
ProdURMapY=2051005.23286800
ProdLRMapX=373416.66169100
ProdLRMapY=2040509.23286800
ProdLLMapX=384360.66169100
ProdLLMapY=2040509.23286800
Out of this, i need to display only the following :
NoScans
NoPixels
ProdULLat
ProdULLon
ProdLRLat
ProdLRLon

public class Test {
public String getValue(String str, String strDelim, String keyValueDelim, String key){
StringTokenizer tokens = new StringTokenizer(str, strDelim);
String sentence;
while(tokens.hasMoreElements()){
sentence = tokens.nextToken();
if(sentence.contains(key)){
return sentence.split(keyValueDelim)[1];
}
}
return null;
}
public static void main(String[] args) {
System.out.println(new Test().getValue("apple = 23456, mango = 12345, orange= 76548, guava = 56734", ",", "=", "apple"));
}
}
" I noticed you have edited your question and added your code. for your new version question you can still simply call method while reading the String from the file and get your desire value ! "

I have written code assuming you have already stored data from file to a String,
public static void main(String[] args) {
try {
String[] CONSTANTS = {"apple", "guava"};
String input = "apple = 23456, mango = 12345, orange= 76548, guava = 56734";
String[] token = input.split(",");
for(String eachToken : token) {
String[] subToken = eachToken.split("=");
// checking whether this data is required or not.
if(subToken[0].trim().equals(CONSTANTS[0]) || subToken[0].trim().equals(CONSTANTS[1])) {
System.out.println("No Need to do anything");
} else {
System.out.println(subToken[0] + " " + subToken[1]);
}
}
} catch(Exception e) {
e.printStackTrace();
}
}

read a complete line using bufferedreader and pass it to stringtokenizer with tokenizer as "="[as you mentioned in your file].
for more please paste your file and what you have tried so far..
ArrayList<String> list = new ArrayList<String>();
list.add("NoScans");
list.add("NoPixels");
list.add("ProdULLat");
list.add("ProdULLon");
list.add("ProdLRLat");
list.add("ProdLRLon");
//read a line from a file.
while ((line = br.readLine()) != null) {
lineNumber++;
//use 'equal to' as token separator
st = new StringTokenizer(line, "=");
//check for tokens from the above string tokenizer.
while (st.hasMoreTokens()) {
String key = st.nextToken(); //this will give the first token eg: NoScans
String value = st.nextToken(); //this will give the second token eg:10496
//check the value is present in the list or not. If it is present then print
//the value else leave it as it is.
if(list.contains(key){
//display csv values
System.out.print(key+"="+ " "+value);
}
}

Trying to figure out why the split method is not printg out right

The words printed out after the split command are not printing out in ascending order. I do not think I have it placed in the right spot of the code, but i am unsure exactly were to place it. It prints out the whole text passage word for word without any punctuation marks as desired, but it wont print in ascending (alphabetical) order. Any help would be great.
public static void main(String[] args) throws
FileNotFoundException, IOException
{
Scanner ci = new Scanner(System.in);
System.out.print("Please enter a text file to open: ");
String filename = ci.next();
System.out.println("");
File file = new File(filename);
BufferedReader br = new BufferedReader(new FileReader(file));
StringBuilder sb = new StringBuilder();
String str;
while((str = br.readLine())!= null)
{
String sp[] = str.split("[\\s\\.,;:\\?!]+");
for (String sr : sp )
{
System.out.println(sr);
}
sb.append(str);
sb.append(" ");
// System.out.println(str);
}
ArrayList<String> text = new ArrayList<>();
StringTokenizer st = new StringTokenizer(sb.toString().toLowerCase());
while(st.hasMoreTokens())
{
String s = st.nextToken();
text.add(s);
}
System.out.println("\n" + "Words Printed out in Ascending "
+ "(alphabetical) order: " + "\n");
List<String> arrayList = new ArrayList<>(text);
Collections.sort(arrayList);
for (Object ob : arrayList)
{
System.out.println("\t" + ob.toString());
}
}

You're printing the words twice, once after you've splitted the text on punctuation, then again after you've glued it back together, splitted it again and finally sorted it.
However, in the line-reading while you're splitting each line, but you're then ignoring the result of that split (besides printing it) and you continue to add the original line to sb.
You probably want to turn sb into an ArrayList, then add each word (sr from sp in your for(sr : sp) loop) to sb and sort that.
You can then remove the whole part with StringTokenizer and sort the ArrayList immediately. Like this:
ArrayList<String> sb = new ArrayList<String>();
String str;
while((str = br.readLine())!= null)
{
String sp[] = str.split("[^\\w]+");
for (String sr : sp )
{
sb.add(sr);
// System.out.println(sr);
}
}
sb = Collections.sort(sb);