JAVA input/output stream experiment

1. Print command line parameters

Code:

1. Import java. Io .*;
2. Public class test1 {
3. Public static void main (string [] ARGs ){
4. For (INT I = 0; I <args. length; I ++ ){
5. System. Out. Print (ARGs [I]);
6. }
7. System. Out. println ();
8. }
9. }

2. output the content in a file to the console as is

Code:

1. Import java. Io .*;
3. Public class Test2 {
4. Public static void main (string [] ARGs ){
5. System. Out. println ("Please enter the file path :");
6. Try {
7. String filename = "";
8. While (true ){
9. Int readbyte = system. In. Read ();
10. If (readbyte =-1 | readbyte = '/R '){
11. Break;
12. } Else {
13. Filename + = (char) readbyte;
14. }
15. }
16. Char [] buffer = new char [20];
17. Filereader Fr = new filereader (filename );
18. While (true ){
19. Int length = Fr. Read (buffer );
20. If (length <0 ){
21. Break;
22. } Else {
23. String text = new string (buffer, 0, length );
24. System. Out. Print (text );
25. }
26. }
27. } Catch (ioexception e ){
28. E. printstacktrace ();
29. }
30. }
31. }

3. Write the content in one file to another file

Code:

1. Import java. Io .*;
3. Public class test3 {
4. Public static void main (string [] ARGs ){
5. Filerwtest FRW = new filerwtest ();
6. }
7. }
9. Class filerwtest {
10. Bufferedreader BR;
11. Bufferedwriter bw;
12. File in = new file ("input.txt ");
13. File out = new file ("output.txt ");
14. Char [] cbuf = new char [1024];
15. Int off = 0;
16. Public filerwtest (){
17. Try {
18. If (! In. exists ()){
19. In. createnewfile ();
20. }
21. If (! Out. exists ()){
22. Out. createnewfile ();
23. }
24. BR = new bufferedreader (New inputstreamreader (New fileinputstream (in )));
25. BW = new bufferedwriter (New outputstreamwriter (New fileoutputstream (out )));
26. While (Br. Readline ()! = NULL ){
27. BR. Read (cbuf, off, off + 1024 );
28. Bw. Write (cbuf, off, off + 1024 );
29. Off + = 1024;
30. }
31. BR. Close ();
32. Bw. Close ();
33. } Catch (ioexception e ){
34. E. printstacktrace ();
35. }
36. }
37. }

4. output the daffodils to a file.

Code:

1. Import java. Io .*;
3. Public class test4 {
4. Public static void main (string [] ARGs ){
5. Try {
6. Byte [];
7. Fileoutputstream Fos = new fileoutputstream ("data.txt", true );
8. For (INT I = 100; I <= 999; I ++ ){
9. Int A = I/100;
10. Int B = I %100/10;
11. Int c = I % 10;
12. If (I = (INT) (math. Pow (A, 3) + math. Pow (B, 3) + math. Pow (C, 3 ))){
13. String S = new string (I + "=" + A + "*" + A + "*" + A +
14. "+" + B + "*" + B + "*" + B +
15. "+" + C + "*" + C + "*" + C + "/N ");
17. By = S. getbytes ();
18. FOS. Write (by, 0, by. Length );
19. } Else {
20. Continue;
21. }
22. }
23. FOS. Close ();
24. } Catch (ioexception e ){
25. E. printstacktrace ();
26. }
27. }
28. }

5. Read the content of a file, convert uppercase letters into lowercase letters, and output them to another file.

Code:

1. Import java. Io .*;
3. Public class test5 {
4. Static bufferedreader BR;
5. Static bufferedwriter bw;
6. Static file in = new file ("test5.java ");
7. Static file out = new file ("result.txt ");
8. Static string str1;
9. Static string str2;
10. Public static void main (string [] ARGs ){
11. Try {
12. If (! In. exists ()){
13. In. createnewfile ();
14. }
15. If (! Out. exists ()){
16. Out. createnewfile ();
17. }
18. BR = new bufferedreader (New inputstreamreader (New fileinputstream (in )));
19. BW = new bufferedwriter (New outputstreamwriter (New fileoutputstream (out )));
20. While (str1 = Br. Readline ())! = NULL ){
21. Str2 = str1.tolowercase ();
22. Bw. Write (str2, 0, str2.length ());
23. Bw. newline ();
24. }
25. BR. Close ();
26. Bw. Close ();
27. } Catch (ioexception e ){
28. E. printstacktrace ();
29. }
30. }
31. }