Java uses the readLine() function of the BufferedReader class to read the file content line by line

Java uses the readLine() function of the BufferedReader class to read the file content line by line

BufferedReader is a common class used to read files in Java. It improves reading efficiency through buffering and provides the readLine() function to read file contents line by line. In this article, we will learn how to use the readLine() function of the BufferedReader class to read the file content line by line, and attach the corresponding code examples.

First, we need to import the java.io package in order to use the BufferedReader class and related exception classes. The code looks like this:

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

Next, we need to create a BufferedReader object and pass it the file to be read as a parameter. The code is as follows:

try {
    BufferedReader reader = new BufferedReader(new FileReader("文件路径"));
} catch (IOException e) {
    e.printStackTrace();
}

In the above code, we use the try-catch statement to catch possible IOException exceptions. This exception is thrown if the file does not exist or cannot be read.

Now, we can use the readLine() function to read the file content line by line. The specific implementation method is to use a loop, and each loop calls the readLine() function to read a line of data and print it out. When the readLine() function returns null, it means that all the contents of the file have been read.

The code example is as follows:

try {
    BufferedReader reader = new BufferedReader(new FileReader("文件路径"));
    String line;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }
    reader.close();
} catch (IOException e) {
    e.printStackTrace();
}

In the above code, we use a while loop to continuously call the readLine() function to print out the content of each line read. When the readLine() function returns null, it means that all the contents of the file have been read. At this time, we need to call the close() function to close the BufferedReader object.

You need to pay attention to the following points when reading files:

1. You need to provide the correct file path. If the file path is incorrect or the file does not exist, an IOException will be thrown.
2. After reading is completed, the close() function needs to be called to close the BufferedReader object to release resources.
3. Pay attention to exception handling when writing code to avoid program crashes.

To summarize, Java can easily read the file content line by line using the readLine() function of the BufferedReader class. Through the code examples in this article, we can better understand and use this function to operate files more efficiently. Hope this article is helpful to everyone!

The above is the detailed content of Java uses the readLine() function of the BufferedReader class to read the file content line by line. For more information, please follow other related articles on the PHP Chinese website!