Java read-write file and input processing by line

First, we look at Python is very simple:

1. Read the file:

1 with open ("/path/file","R") as fr:2 for in       fr.readlines ():3         do_somethings (line)

2. Write files:

1 with open ("/path/file","w/a") as fr:  2     fr.write ("ssssssss")

Second, the above knowledge a primer, not the focus, or to learn the Java file read and write operations:

The most common is to read and write by line, of course, there will be a bit of other reading and writing methods:

1, read by line:

1File File =NewFile ("Absolute path");2BufferedReader BufferedReader =NewBufferedReader (Newfilereader (file));3String str =NULL;4  while(str = bufferedreader.readline ())! =NULL)  5{  6     System.out.println (str); 7 }8Bufferedreader.close ();

2, write by line:

1 New FileWriter ("Absolute path",true); 2 // true indicates append, otherwise overwrite write, overwrite write does not need true 3 filew.write ("\ntest\n"); 4 filew.close ();

1 list<string> b = files.readalllines (Paths.get ("/users/a003797/desktop/a1.txt")); 2  for (String item:b) {3    System.out.println (item)    ;     4 }

3. Other reading methods:

1 // Read all bytes: 2 byte [] A = Files.readallbytes (Paths.get ("/users/a003797/desktop/a1.txt"));

Third, input processing

1 ImportJava.io.*;2 3  Public classtest{4      Public Static voidMain (String args[])throwsIOException {5BufferedReader br =NewBufferedReader (NewInputStreamReader (system.in)); 6          while(true){7String string =br.readline ();8 System.out.println (string);9         }Ten     } One}

Java read-write file and input processing by line