Develop Reference

Java - String splitting

I read a txt with data in the following format: Name Address Hobbies
Example(Bob Smith ABC Street Swimming)
and Assigned it into String z
Then I used z.split to separate each field using " " as the delimiter(space) but it separated Bob Smith into two different strings while it should be as one field, same with the address. Is there a method I can use to get it in the particular format I want?
P.S Apologies if I explained it vaguely, English isn't my first language.
String z;
try {
BufferedReader br = new BufferedReader(new FileReader("desc.txt"));
z = br.readLine();
} catch(IOException io) {
io.printStackTrace();
}
String[] temp = z.split(" ");

If the format of name and address parts is fixed to consist of two parts, you could just join them:
String z = ""; // z must be initialized
// use try-with-resources to ensure the reader is closed properly
try (BufferedReader br = new BufferedReader(new FileReader("desc.txt"))) {
z = br.readLine();
} catch(IOException io) {
io.printStackTrace();
}
String[] temp = z.split(" ");
String name = String.join(" ", temp[0], temp[1]);
String address = String.join(" ", temp[2], temp[3]);
String hobby = temp[4];
Another option could be to create a format string as a regular expression and use it to parse the input line using named groups (?<group_name>capturing text):
// use named groups to define parts of the line
Pattern format = Pattern.compile("(?<name>\\w+\\s\\w+)\\s(?<address>\\w+\\s\\w+)\\s(?<hobby>\\w+)");
Matcher match = format.matcher(z);
if (match.matches()) {
String name = match.group("name");
String address = match.group("address");
String hobby = match.group("hobby");
System.out.printf("Input line matched: name=%s address=%s hobby=%s%n", name, address, hobby);
} else {
System.out.println("Input line not matching: " + z);
}

I can think of three solutions.
In order from best to worst:
Different delimiter
Enforce the format to always have two names, two address parts and one hobby
Have a dictionary with names and hobbies, check each word to determine which type it is and then group them together as needed.
(The 3rd option is not meant as a serious alternative.)

As others have mentioned, using spaces as both field delimiter and inside fields is problematic. You could use a regex pattern to split the line (paste (\w+ \w+) (\w+ \w+) (.+) in Regex101 for an explanation):
Pattern pattern = Pattern.compile("(\\w+ \\w+) (\\w+ \\w+) (.+)");
Matcher matcher = pattern.matcher("Bob Smith ABC Street Bowling Fishing Rollerblading");
System.out.println("matcher.matches() = " + matcher.matches());
for (int i = 0; i <= matcher.groupCount(); i++) {
System.out.println("matcher.group(" + i + ") = " + matcher.group(i));
}
This would give the following output:
matcher.matches() = true
matcher.group(0) = Bob Smith ABC Street Bowling Fishing Rollerblading
matcher.group(1) = Bob Smith
matcher.group(2) = ABC Street
matcher.group(3) = Bowling Fishing Rollerblading
However this only works for this exact format. If you get a line with three name parts for example:
John B Smith ABC Street Swimming
This will get split into John B as the name, Smith ABC as the address and Street Swimming as hobbies.
So either make 100% sure your input will always match this format or use a different delimiter.

The split() method majorly works on the 2 things:
Delimiter and
The String Object
Sometimes on limit too.
Whatever limit you will provide, the split() method will do its work according to that.
It doesn't understand whether the left substring is a name or not, same as for the right substring.
Have a look at this code snippet:
String assets = "Gold:Stocks:Fixed Income:Commodity:Interest Rates";
String[] splits = assets.split(":");
System.out.println("splits.size: " + splits.length);
for(String asset: splits){
System.out.println(assets);
}
OutPut
splits.size: 5
Gold
Stocks
Fixed Income // with space
Commodity
Interest Rates // with space
The output came with spaces because I provided the ; as a delimiter.
This probably helped you to get your answer.
Find Detailed Information on Split():
Top 5 Use cases of Split()
Java Docs : Split()

It depends on the data you're dealing with. Will the name always consist of a first and last name? Then you can simply combine the first two elements from the resulting array into a new string.
Otherwise, you might have to find a different way to separate out the different pieces within the txt file. Possibly a comma? Some character that you know won't ever be used in your normal data.

Assuming that every line follows the format
Bob Smith ABC Street Swimming
ie, name surname.... this code can manually manipulate the data for you:
String[] temp = z.split(" ");
String[] temp2 = new String[temp.length - 1];
temp2[0] = temp[0] + " " + temp[1];
for (int i = 2; i < temp.length; i++) {
temp2[i] = temp2[i];
}
temp = temp2;

How to parse a line of text with two separate pieces of data?

I'm new to parsing (and new to Java), so I just want to be sure I'm conceptualizing this correctly.
I've written a program that allows the user to paste text into a text field, then click the "parse data" button. This button parses the text for two pieces of data: a name and a number.
The text data is generally pasted by the user in this form:
john 48915
beth 10431
frank 10112
anne 34887
taserface 90090
bill 56448
I'm using the regular expression "^\d+\t.*\d+$" to detect the pattern, and after the pattern is confirmed, my parse data code does the following:
Scanner parser = new Scanner(inputText);
parser.useDelimiter("\\n");
while (parser.hasNext()) {
String nextToken = parser.next();
String name = nextToken.trim();
// how do I get the number?
You'll notice the \n delimiter, which parses data at the new line character. This breaks the data up into rows, but does not break each row into two separate data points. I need to grab both the name and the number separately.
I believe I should be using a space delimiter, but I'm not sure if I should be doing this in one or two different steps. The confusion, I believe, stems from my limited understanding of how the Scanner does its work. But after a review of the Java documentation, I'm still not really sure.
Current output:
john 48915
beth 10431
frank 10112
etc.
Expected output:
john
48915
beth
10431
etc.
Should I be doing two different loops of parsing, or can I get the work done in the same pass?

Your problem is that you are usimg \n as delimiter.
This leads to the behavior that the input you are passing to your scanner is only delimited at linebreaks and not as you are expecting also at whitespaces.
One solution would that would work is to simply delete the following line: parser.useDelimiter("\\n");
A solution that would also work is the following:
try (Scanner parser = new Scanner(inputText)) {
while (parser.hasNextLine()) {
String nextLine = parser.nextLine();
String[] strings = nextLine.split("\\s");
// Here you can use any pattern to split the line
String name = strings[0];
String number = strings[1];
System.out.printf("%s%n%s%n", name, number);
}
}
This leads to the following output:
john
48915
beth
10431
frank
10112
anne
34887
taserface
90090
bill
56448
The solution gives you some more controll over the lines and how to parse the name and number.

Here is an example implementation for your case, which offers more control and flexibility to accommodate change of delimiters -
import java.util.Arrays;
public class StringSplitExample {
public static void main(String []args){
String content = "john 48915\n"
+ "beth 10431\n"
+ "frank 10112\n"
+ "anne 34887\n"
+ "taserface 90090\n"
+ "bill 56448";
String[] dataset = content.split("\\n|\\s");
for (String value : dataset) {
System.out.println(value);
}
}
}
And, following is the output for the above code snippet -
john
48915
beth
10431
frank
10112
anne
34887
taserface
90090
bill
56448

You can achieve this functionality with String spilt method, below is same program and output as you desire.
I think without space user can not go next line while filling form.
public class ParseLineText {
public static void main(String[] args) {
String textData = "john 48915 " +
"beth 10431 " +
"frank 10112 " +
"anne 34887 " +
"taserface 90090 " +
"bill 56448 ";
String[] data = textData.split("\\s");
for (String text : data) {
System.out.println(text);
}
}
}
Output:
john
48915
beth
10431
frank
10112
anne
34887
taserface
90090
bill
56448

Sort a some words in a string

Assuming there is a file:
Virginia Tyler Taylor Wilson
Ohio Grant Hayes Garfield Harrison_B McKinley Taft Harding
Massachusetts Kennedy Bush_GHW
New_York VanBuren Fillmore Roosevelt_T Roosevelt_F
I need to sort it in order, and below is my code:
TreeMap<String, String> map = new TreeMap<String, String>();
while (infile1.ready()){
String line = infile1.readLine();
String s = line.substring(0, line.indexOf(" "));
String p = line.substring(line.indexOf(" "));
map.put(s, p);
}
for (String p : map.keySet()){
System.out.println(p + " " + map.get(p));
}
My output is:
Massachusetts Kennedy Bush_GHW
New_York VanBuren Fillmore Roosevelt_T Roosevelt_F
Ohio Grant Hayes Garfield Harrison_B McKinley Taft Harding
Virginia Tyler Taylor Wilson
The expected output is:
Massachusetts **Bush_GHW Kennedy**
New_York **Fillmore Roosevelt_F Roosevelt_T VanBuren**
Ohio **Garfield Grant Harding Harrison_B Hayes McKinley Taft**
Virginia **Taylor Tyler Wilson**
The only difference is the order in the value, where I bold it in the expected output.
Is there a fast way to sort String p and puts it into the map?

you can write in short way
Arrays.sort(line.substring(line.indexOf(" ")).split(" "));

try this
String[] ps = line.substring(line.indexOf(" ")).split(" ");
Arrays.sort(ps);
then try combine ps to p with " ";

Massachusetts **Bush_GHW Kennedy**
New_York **Fillmore Roosevelt_F Roosevelt_T VanBuren**
Ohio **Garfield Grant Harding Harrison_B Hayes McKinley Taft**
Virginia **Taylor Tyler Wilson**
In your above expected output how Bush Comes after mass..
So please explore output correctly.

User input first and last name , print out intisials java eclipse

So , im having a piece of trouble here , tried with tutorials to fix it but nothing really helped me out saw something about printout string 0,1 etc but didnt work eather.
What the program does atm : Asks user for first/last name and prints it out first +last name
what i want it to do is print out the intisials of the users first and last name, any ideas how to fix this? Please help , Thanks in advance!
My code looks like this atm
package com.example.sträng.main;
import java.util.Scanner;
public class Application {
public static void main(String[] args) {
String firstName,
lastName;
//Create scanner to obtain user input
Scanner scanner1 = new Scanner( System.in );
//obtain user input
System.out.print("Enter your first name: ");
firstName = scanner1.nextLine();
System.out.print("Enter your last name: ");
lastName = scanner1.nextLine();
//output information
System.out.print("Your first name is " + firstName + " and your last name is "+ lastName);
}
}

You get the 21st character from a String using String.charAt(21).
How to get the initials, I leave as an excercise for you.
Please note, that char is a strange datatype in Java. It represents a character, but works like a number, that's why you get a strange number if you "concatenate" two chars. If you want to create a String out of chars, you have some options, such as:
char c1;
char c2;
String str = "" + c1 + c2;
or
char c1;
char c2;
String str = new String(new char[] {c1, c2});

String firstInitial = firstName.substring(0,1);
String secondInitial = lastName.substring(0,1);

What is wrong with Java File read?

I deal with a file problem.
IBM 7918 Ayse Durlanik 7600 Computer
------------------------------------
Gama 2342 Mehmet Guzel 8300 Civil
------------------------------------
Lafarge 3242 Ahmet Bilir 4700 Chemical
------------------------------------
Intel 3255 Serhan Atmaca 9200 Electrical
------------------------------------
Bilkent 3452 Fatma Guler 2500 Computer
------------------------------------
Public 1020 Aysen Durmaz 1500 Mechanical
------------------------------------
Havelsan 2454 Sule Dilbaz 2800 Electrical
------------------------------------
Tai 3473 Fethi Oktam 3600 Computer
------------------------------------
Nurol 4973 Ayhan Ak 4100 Civil
------------------------------------
Pfizer 3000 Fusun Ot 2650 Chemical
------------------------------------
This is the text file and I don't want to read this =
"------------------------------------ "
Here is the method:
Scanner scn = null;
File fp = new File("C:/Users/Efe/Desktop/engineers.txt");
try {
scn = new Scanner(fp);
while (scn.hasNextLine()) {
{
if (!scn.next().equals("------------------------------------")) {
String comp = scn.next();
int id = Integer.parseInt(scn.next());
String name = scn.next();
String surname = scn.next();
double sal = Double.parseDouble(scn.next());
String area = scn.next();
Engineer e = new Engineer(comp, id, name, surname, sal, area);
list.add(e);
}
}
scn.close();
}
This is the code where I get an exception at run-time:
Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException:
For input string: "Ayse" at
java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
What is wrong with the code?

You're off by one...in the line
if (!scn.next().equals("------------------------------------")) {
if the next token is not the dashed line, then it is lost. Consider assigning it to a temporary variable.
In your case, "IBM" is lost, comp == 7918, and parseInt is called with an argument of "Ayse", leading to the runtime exception.

This is when application trying to convert string to one of the numeric types, but that string does have the appropriate format to convert.
Can you show further "IBM 7918 Ayse Durlanik 7600 Computer"