How to create read-only file in Java? (code example)

In java, it is very easy to make a file read-only. The following article will introduce to you how to make a file read-only, how to check whether a file is read-only, and how to create a writable read-only file. I hope it will be helpful to you.

1. How to create a read-only file

To make the file read-only, we only need to change the file Just change the attribute to read-only; you can use the setReadOnly() method of the File class to achieve this. It will return a boolean value so we can further verify that the operation was successful.

Example: Change the properties of the "Myfile.txt" file that exists in the c drive to read-only

import java.io.File;
import java.io.IOException;
 
public class ReadOnlyChangeExample
{
 
    public static void main(String[] args) throws IOException
    {
    File myfile = new File("C://Myfile.txt");
    //making the file read only
    boolean flag = myfile.setReadOnly();
    if (flag==true)
    {
       System.out.println("文件已成功转换为只读模式!!");
    }
    else
    {
       System.out.println("操作不成功，请重新操作!!");
    }
    }
}

Output:

文件已成功转换为只读模式!!

2. Check whether the file is in read-only mode

In order to check the file attributes, we can use the canWrite() method of the file class; this method can check whether the file is writable or read-only of. This method returns true if the file is in writable mode, false otherwise.

Example: In the above example, the properties of the "Myfile.txt" file have been set to read-only, so when the "Myfile.txt" file is checked, the output "The file is read-only" will be returned. ”

import java.io.File;
import java.io.IOException;
 
public class CheckAttributes
{
    public static void main(String[] args) throws IOException
    {
    File myfile = new File("C://Myfile.txt");
    if (myfile.canWrite())
    {
       System.out.println("文件是可写的");
    }
    else
    {
       System.out.println("文件是只读的");
    }
    }
}

Output:

文件是只读的

3. How to create a writable read-only file in java

To To set a read-only file to a writable file, we can use the setWritable() method. This method can also be used to make the file read-only:

● file.setWritable(true): Make the file writable.

● file.setWritable(false): Make the file read-only.

Code example:

import java.io.File;
import java.io.IOException;
 
public class MakeWritable
{
 
    public static void main(String[] args) throws IOException
    {
    File myfile = new File("C://Myfile.txt");
    //将文件模式更改为可写
    myfile.setWritable(true);
    if (myfile.canWrite())
    {
       System.out.println("文件是可写的");
    }
    else
    {
       System.out.println("文件是只读的");
    }
    }
}

Output:

文件是可写的

Related video tutorial recommendations: "Java Tutorial"

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