Is it overly redundant and considered bad style to check that the file object exists before a try catch. Since the FileNotFoundException would be called anyways if the file object did not exist? Answer Yes, the exists test is redundant. An implicit existence test happens within the Scanner. (Actually, it occurs in the syscall that opens the file.) And it
Tag: io
How to use SequenceInputStream?
🍳Background 1.I was learning the basic grammar of input and output in java. 2.But I found that the SequenceInputStream worked strangely. ⚡Code ⚡outcome 🔑Question 1.Why did the method(read) stop when meet EOF? 2.How to read the next Stream? Answer Why did the method(read) stop when meet EOF? You might be expecting it to read “learn!java” on the first call to
How can I remove last 2 lines in text file in Java?
I want remove last 2 lines in my text file using java. I tried 4 or 5 different ways about this, but I can’t find working code. I will edit file like this: I want delete “]” , “}” and add “example2”. How can I do that ? (I’m using SE 1.8 , maybe version have an effect on this)
How to get rid of – “java.io.IOException: The system cannot find the path specified”
I am trying to create a file and write to it, but I’m getting error in my path. Here is my code: Answer You can’t have a folder and a file with the same name in the same path location. That’s why this code fails: Here you’re first creating a folder, and then you’re attempting to create a file with
Does commons-io’s FileUtils.readFileToByteArray close the newly created stream?
I’m creating a program that produce checksums for each files in directory. I’m using FileUtils.readFileToByteArray which internally creates a new FileInputStream. The problem is I didn’t find where the stream is closed and wondering about a possible memory leak. So I’m asking: does this method close the stream after reading it? Answer Short answer: yes, it closes the stream. Slightly
How to save the matrix in the text file
I just want to input the matrix in the text file, but the result are clearly different. I don’t have any ideas. I expect but in the file is Answer You can try this: This will print the values like a table:
How to perform unbuffered input in Java (if at all possible)?
Java Beginner here. When we input a string, we have to press the enter key to let the program know that the user has done inputting. Is there a way where we use another key instead of enter key (for example a question mark key) to input a string? Answer Ever heard of something called a “buffer”? It is a
get removable sd card path in android
How can i get extSdcard path in android? There are 2 storage, first external storage in which all the phones have it but there is second storage which is called removable storage (micro sdcard). I want to get the path to the micro sdcard in android, how is that possible? Answer Starting from KitKat, you have access to a method
Ignoring blank lines in CSV file in Java
I am trying to iterate through a CSV file in Java. It iterates through the entire file, but will get to the end of the file and try to read the next blank line and throw an error. My code is below. Like I typed, this works fine until it gets to the end of the file. When it gets
Code in “catch” block not executing
please help me understand why:) My program reach the “try” line, but seems to skip the “catch”, Although its printing the stacktrace… I’m using JOptionPane in my catch, but also System.out.println() not working. Code: Exception: Answer There is an NullPointerException internally just before the FileNotFoundException From your log. You can make sure it from following. This code here only for