The below program outlines what you need to do. MappedByteBuffer, a representation of the memory area of your file's contents can be created from the channel that you get access from the RandomAccessFile class. Open your files by using the RandomAccessFile class and ask for the channel from this object if you want to memory map the two files. The OS allocates the memory itself and hence the program doesn't consume heap memory. Files that are mapped by the memory are read directly by your operating system. For a very fast and efficient solution, you need to use a highly advanced technique called memory-mapping. This program is simple in nature and may take up a lot of memory and time to execute. ('File1 has '+line1+' and File2 has '+line2+' at line '+lineNum) Public static void main(String args) throws IOExceptionīufferedReader reader1 = new BufferedReader(new FileReader('C:\file1.txt')) īufferedReader reader2 = new BufferedReader(new FileReader('C:\file2.txt')) Hence, we will be using a highly advanced technique called memory mapping using RandomAccessFile from java.io package. The static code analysis tools Findbugs, PMD and Checkstyle are widely used in the Java development community.

First, we will be comparing the files using BufferedReader but this way of comparing files is not memory efficient and requires more execution time.

You can quickly identify the duplicate lines, which allows you to remove the file entirely. Comparing files in java also can help you to differentiate between the local and the remote files. In this program, we will see how we can compare two different files in Java. When you are learning Java, network programming can be a great source of practicing Java.

Java code comparison tool