java - why does "STRING".getBytes() work different according to the Operation System -

i running code below , getting different outcome "some_string".getbytes() depending if in windows or unix. issue happens string (i tried simple abc , same problem.

see differences below printed in console.

the code below well-tested using java 7. if copy entirely run.

additionally, see difference in hexadecimal in 2 images below. first 2 images shows file created in windows. can see hexadecimal values ansi , ebcdic respectively. third image, black one, unix. can see hexadecimal (-c option) , character readable in believe ebcdic.

so, straight question is: why such code work different since using java 7 in both case? should check especific property in somewhere? maybe, java in windows default format , in unix another. if so, property must check or settup?

unix console:

$ ./java -cp /usr/test.jar test.mainframe.read.test.testgetbytes h = 76 - l < wasn't found 

windows console:

h = 60 - < h1 = 69 - e h2 = 79 - o h3 = 77 - m h4 = 62 - > end of message found 

the entire code:

package test.mainframe.read.test;  import java.util.arraylist;  public class testgetbytes {         public static void main(string[] args) {               try {                      arraylist ipmmessage = new arraylist();                      ipmmessage.add(newline());                       //windows path                      writemessage("c:/temp/test_bytes.ipm", ipmmessage);                      reformatfile("c:/temp/test_bytes.ipm");                      //unix path                      //writemessage("/usr/temp/test_bytes.ipm", ipmmessage);                      //reformatfile("/usr/temp/test_bytes.ipm");               } catch (exception e) {                       system.out.println(e.getmessage());               }        }         public static byte[] newline() {               return "<eom>".getbytes();        }         public static void writemessage(string filename, arraylist ipmmessage)                      throws java.io.filenotfoundexception, java.io.ioexception {                java.io.dataoutputstream dos = new java.io.dataoutputstream(                            new java.io.fileoutputstream(filename, true));               (int = 0; < ipmmessage.size(); i++) {                      try {                            int[] intvalues = (int[]) ipmmessage.get(i);                            (int j = 0; j < intvalues.length; j++) {                                   dos.write(intvalues[j]);                            }                      } catch (classcastexception e) {                            byte[] bytevalues = (byte[]) ipmmessage.get(i);                            dos.write(bytevalues);                      }               }               dos.flush();               dos.close();         }         // reformat u1014        public static void reformatfile(string filename)                      throws java.io.filenotfoundexception, java.io.ioexception {               java.io.fileinputstream fis = new java.io.fileinputstream(filename);               java.io.datainputstream br = new java.io.datainputstream(fis);                int h = br.read();               system.out.println("h = " + h + " - " + (char)h);                if ((char) h == '<') {// check <eom>                       int h1 = br.read();                      system.out.println("h1 = " + h1 + " - " + (char)h1);                      int h2 = br.read();                      system.out.println("h2 = " + h2 + " - " + (char)h2);                      int h3 = br.read();                      system.out.println("h3 = " + h3 + " - " + (char)h3);                      int h4 = br.read();                      system.out.println("h4 = " + h4 + " - " + (char)h4);                      if ((char) h1 == 'e' && (char) h2 == 'o' && (char) h3 == 'm'                                   && (char) h4 == '>') {                            system.out.println("end of message found");                      }                      else{                            system.out.println("eom not found < found");                      }               }               else{                      system.out.println("< wasn't found");               }        } } 

you not specifying charset when calling getbytes(), uses default charset of underlying platform (or of java if specified when java started). stated in string documentation:

public byte[] getbytes()

encodes string sequence of bytes using platform's default charset, storing result new byte array.

getbytes() has overloaded version lets specify charset in code.

public byte[] getbytes(charset charset)

encodes string sequence of bytes using given charset, storing result new byte array.