用Java比较具有特定结构的文件

Question

I have two txt files with a specific structure. There should be som empty rows and rows with some data. Something like this:

@RELATION Table

@RECORD 1
ID '5'
SOMETHING '10'

The point is, there can be 10 'empty' rows in one file and there can none in second and if the data equals, it should not matter. Any ideas how to effectively do it with big files ?

Answer 1

BufferedReader should be used to read from file, supplying a FileReader to its constructor: https://docs.oracle.com/javase/7/docs/api/java/io/BufferedReader.html

So you will have two of them, one for each file.

Have an "infinite loop" such as: while(true){}

Within this container loop, you should have two internal loops, one for each file.

In each internal loop, using the method readLine() you should advance the cursor to the next line.

declare this outside of the container loop:

String lineFromFileA, lineFromFileB;

and then:

while((lineFromFileA = bufferedReaderA.readLine()) != null){
    if(!lineFromFileA.isEmpty())
        break;
}

do the same with lineFromLineB.

an alternative to the above loop is:

while((lineFromFileA = bufferedReaderA.readLine()) != null && lineFromFileA.isEmpty());

After the two internal loops, both lineFromFileA and lineFromFileB are either null or has a value that is not an empty String.

If both are null, then you are done with the comparison, the two files are equal and you may return true from the function.

If one contains null and the other does not, return false. The files are different.

If both are not null, then check the equals() method if the two Strings are identical, if they are not, return false from the function. If they are equal, do nothing, the next iteration of the container loop will handle the next line.