Java file read/write operations

Write a string to a file:

Code:

1. Import java. Io .*;
3. Class fileoutputdemo {
4. Public static void main (string ARGs []) {
5. Fileoutputstream out; // declare a file output object
6. Printstream P; // declare a print Stream Object
8. Try {
9. // Connected to "myfile.txt"
10. Out = new fileoutputstream ("C:/a.txt ");
11. // Connect print stream to the output stream
12. P = new printstream (out );
13. P. println ("this is written to a file ");
14. P. Close ();
15. } Catch (exception e ){
16. System. Err. println ("error writing to file ");
17. }
18. }
19. }

Java reads the file content:

Code:

1. Import java. Io .*;
3. Class fileinputdemo {
4. Public static void main (string ARGs []) {
5. // Args. length is equivalent to argc in C
6. Try {
7. // Open the file that is the first command line parameter
8. Fileinputstream fstream = new fileinputstream ("C:/B .txt ");
9. // Convert our input stream to a datainputstream
10. Datainputstream in = new datainputstream (fstream );
11. // Continue to read lines while there are still some left
12. // Read
13. String S = "";
14. While (in. Available ()! = 0 ){
15. // Print file line to screen
16. S = in. Readline ();
17. System. Out. println (s );
18. }
19. // String RegEx = "src = /"";
20. // S = S. replaceall (RegEx, "str =/" http://article.star.com: 8081/temp /");
21. In. Close ();
22. } Catch (Exception e ){
23. System. err. println ("File input error ");
24. }
26. }
27. }