Скачать или смотреть How to Separate Cars and Bikes from a Text File in Java

Learn how to effectively read from one text file and separate its contents into two distinct files in Java: one for cars and another for bikes.
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This video is based on the question https://stackoverflow.com/q/62682013/ asked by the user 'Ron' ( https://stackoverflow.com/u/13848581/ ) and on the answer https://stackoverflow.com/a/62682230/ provided by the user 'Lennart Steinke' ( https://stackoverflow.com/u/13208674/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Separate Cars and Bikes from a Text File in Java

In the world of programming, being able to read from and write to text files is a fundamental skill. In this post, we will address a common challenge faced by many Java developers: how to read from a single text file and write its contents into two separate files based on specific criteria.

The problem at hand involves a carsAndBikes.txt file that contains a mix of vehicle names—some starting with the letter ‘C’ for Cars and others with ‘B’ for Bikes. The goal is to create two separate text files, one containing only the car names and the other containing only the bike names.

The Problem

You have a text file called carsAndBikes.txt, which includes a list of vehicles. Here’s an important point: the first character of each line indicates the type of vehicle:

C for Car

B for Bike

However, the current implementation you have is mixing the outputs, resulting in both cars and bikes being written to each respective file instead of separating them properly.

The Solution

To tackle this problem, we’ll modify your existing method to read the input file correctly and write the outputs into the two separate files while ensuring each file receives only the appropriate entries.

Steps to Implement the Solution

Open the Input File:
Use BufferedReader to read the contents of the carsAndBikes.txt file.

Open Output Files:
Open cars.txt and bikes.txt for writing before entering the read loop.

Loop Through Each Line:
Read each line from the input file, check its starting character, and write the line to the appropriate output file.

Close All Files:
Ensure that all files are properly closed after the operation is complete.

Here’s how the finalized code looks:

[[See Video to Reveal this Text or Code Snippet]]

Key Changes Explained

File Reading: We're now using BufferedReader which is more efficient for reading text files line by line.

Conditional Check: The if checks are now comparing the starting character of each line (if (line.startsWith("C"))) rather than the file name or previous loop errors.

Open Output Files Once: Both output files (cars.txt and bikes.txt) are opened once outside the loop. This avoids repeatedly opening and closing files for each line, which is inefficient.

Using println: We use println to ensure each vehicle name is added as a new line in the respective files.

By following this structured approach, you will be able to efficiently separate the contents of your text file into two different files, making information handling much more organized.

Happy Coding!