Can't create PNG file with "st_png" function PostGIS and Java

I have this code in Java:

conn = DriverManager.getConnection ("jdbc: postgresql: // localhost: 5432 / postgis_23_sample" "postgres", "admin");

conn.setAutoCommit (false);

String s = "SELECT ST_AsRaster (ST_Buffer (ST_GeomFromText ('LINESTRING (50 50,150 150,150 50)'), 10), 200,200, ARRAY ['8BUI' '8BUI' '8BUI'] ARRAY [118,154,118] ARRAY [0 , 0,0]) ";

PreparedStatement sGetImg = conn.prepareStatement (s);    
SGetImg.executeQuery ResultSet rs = ();    
FileOutputStream fout;

try
{

    rs.next ();    
    fout = new FileOutputStream (new File ("d:  files  save1x.png"));    
    fout.write (rs.getBytes (1));    
    fout.close ();

}

catch (Exception e)    
{

    System.out.println ("Can not create file");    
    e.printStackTrace ();

}

rs.close ();
sGetImg.close ();
conn.close ();

catch (SQLException se) 
{

    System.out.println ("Could not connect: print out a stack trace and exit.");    
    se.printStackTrace ();    
    System.exit (1);

}

....

I created the file but apparently the PNG file is corrupt, you can not open. That I can be doing wrong.

I reviewed the bytes and the query returns the array of bytes me, but does not write the file apparently well.

Postgres 9.4 y PosGis 2.2

SELECT ST_AsPNG(ST_AsRaster (ST_Buffer (ST_GeomFromText ('LINESTRING (50 50,150 150,150 50)'), 10), 200,200, ARRAY ['8BUI' '8BUI' '8BUI'] ARRAY [118,154,118] ARRAY [0 , 0,0]));