We Keep Coding

Read a csv file into one String [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 9 months ago.
Improve this question
I want to essentially read the contents of csv file and want to input into one string to return. I tried this and it doesnt quite work:
File file = new File(aaa.csv);
FileWriter fw = new FileWriter(file);
BufferReader bw = new BufferReader(fw);
String s;
while (bw.readLine() != null) {
s += (bw.readLine());
}
fw.close();
Is there a easier solution to reading csv file into string that works?

To read the entire file, assuming Java 11 and above, you can simply do:
String content = Files.readString(Paths.get("aaa.csv"));
note that if the file is very large memory becomes a problem.

Is it possible to find a word in a txt file and print the line as a string [closed]

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 3 years ago.
Improve this question
I am stuck on some homework as i am new to java and still learning. I am wondering if it is possible to find a word in a .txt file and output the line that the word is on. I also need to allow a user to make a choice based on what is displayed back.
Example :
Word is Details
Txt file contains
Details on lion
Details on tiger
Output : "Details on tiger"
Thank in advanced for any help

This question has been answered before, but anyway You can go with this apporach.
Simply put:
Create a Scanner object and pass the required file into the
constructor as a new file object.
Iterate over the file with a
while loop until you find the specified string.
In order to store the lines that contains the desired word,we decalre a new string variable
Here's the code snippet:
Scanner scanner= new Scanner(new File("filename.txt"));
String lines = "";
while(scanner.hasNextLine()){
String stringLine = scanner.nextLine();
if(stringLine.indexOf("YOUR_WORD") != -1){
//print whatever you want here
System.out.println(stringLine);
//add every line that contains stringLine into another string;
lines+=stringLine;
}
}

how to split a text file by line gaps in java [closed]

Closed. This question needs details or clarity. It is not currently accepting answers.
Want to improve this question? Add details and clarify the problem by editing this post.
Closed 5 years ago.
Improve this question
I am reading a text file in Java that looks like this,
"
Q1. You are given a train data set having 1000 columns and 1 million rows. The data set is based on a classification problem. Your manager has asked you to reduce the dimension of this data so that model computation time can be reduced. Your machine has memory constraints. What would you do? (You are free to make practical assumptions.)
Q2. Is rotation necessary in PCA? If yes, Why? What will happen if you don’t rotate the components?
Q3. You are given a data set. The data set has missing values which spread along 1 standard deviation from the median. What percentage of data would remain unaffected? Why? "
Now, I want to read this file and then store each of these sentences(questions) in a string array. How can I do that in java?
I tried this,
String mlq = new String(Files.readAllBytes(Paths.get("MLques.txt")));
String[] mlq1=mlq.split("\n\n");
But this is not working.

Try this
String mlq = new String(Files.readAllBytes(Paths.get("MLQ.txt")));
String[] mlq1=mlq.split("\r\n\r\n");
System.out.println(mlq1.length);
System.out.println(Arrays.toString(mlq1));
This should do it by line gap of 2 lines.

File file = new File("C:\\MLques.txt");
BufferedReader br = new BufferedReader(new FileReader(file));
String st;
while ((st = br.readLine()) != null) {
System.out.println(st + "\n");
}
I think it will work.

This is a piece of code from one of my project.
public static List<String> readStreamByLines(InputStream in) throws IOException {
return IOUtils.readLines(in, StandardCharsets.UTF_8).stream()
.map(String::trim)
.collect(Collectors.toList());
}
But!!! If you have really big file, then collecting all content into a List is not good. You have to read InputStream line by line and do all you need for every single row.

Reading a file and creating objects from the information [closed]

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 8 years ago.
Improve this question
I have two files and I want to individually read them then use the the first file to create 5 objects and then use the second file to add the parameters to be passed to a constructor, question is is I am not quite sure how to do that.
What I wanted to do was to loop the hasNextLine and assign the next line to a string and have an object created from that string name, then passing variables in the same way but I see that may not be possible in Java. If it isn't what is another way I could approach this?
Well I was trying to do something like this
while(salesPersonScanner.hasNextLine()){
String personName = salesPersonScanner.nextLine();
SalesPerson personName = new SalesPerson();
}

You can use a BufferedReader to iterate over lines:
final BufferedReader reader = new BufferedReader(new FileReader("/path/to/file"));
String line;
while ((line = reader.readLine()) != null) {
// Create your object from the string
}

You have two options:
You can read all of the required parameters from files and then pass them all to the constructor to create a new object.
You can create an object with your constructor and use setters to set each of the instance variables.
I personally suggest the first approach unless you have to set lots of variables.

Moving from buffer to an array for manipulation in Java [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 7 years ago.
Improve this question
I am making a program to take data from a .txt document, I have used the BufferedReader method which goes through the document. It then prints the the documents contents into the console. I cannot however for the life of me figure out how to get the contents from the BufferedReader into a string array so I can then further manipulate it. Any help?

The method Files.readAllLines reads a file into a List<String>, one String per line in the original file. The method Files.readAllBytes just reads a file into a byte array if that's your style. These are both part of the Java NIO 2 library, part of Java SE 7.
Path myFile = Paths.get("hello_world.txt");
List<String> fileLines = Files.readAllLines(myFile);

use DataInputStream instead of BufferedReader
DataInputStream is = new DataInputStream (new FileInputStream ("myFileName"));
then you can store a String with methtod call is.readUTF ();

If you want a String[] array containing the lines of the document, you could use BufferedReader.readLine(), and stuff the lines into a List<String> instead of printing them.
Here's how you can create a list of Strings:
List<String> lines = new ArrayList<String>();
And here's how you can add to it:
String line = null;
while( (line = reader.readLine()) != null ) {
lines.add( line );
}