StringBench.java

    void bench() {
        StringBuilder buf = new StringBuilder();
        for (int i = 0; i<100000; i++)
          buf.append("0123456789あいうえおaiueo");
        
        String s = buf.toString();
        byte[] bytes = s.getBytes();
        char[] chars = s.toCharArray();

        long start = 0;
        
        start = System.currentTimeMillis();
        String z = new String(chars);
        p("srtring from string[" + z.length() + "]: " + (System.currentTimeMillis() - start));
        
        start = System.currentTimeMillis();
        int len = s.length();
        int idx = 0;
        StringBuilder sb = new StringBuilder();
        while (idx < len) {
            char c = s.charAt(idx++);
            sb.append(c);
        }
        String y = sb.toString();
        p("string from stringbuf[" + y.length() + "]: " + (System.currentTimeMillis() - start));
        
        start = System.currentTimeMillis();
        try {
            String x = new String(bytes, "UTF-8");
            p("string from bytes[" + x.length() + "]: " + (System.currentTimeMillis() - start));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

    }