java 格式转换

1.int转String

int a = 100; String b = String.valueOf(a)

2.String转int

String a = "100"; int b = Integer.parseInt(a)

3.编解码字节

        String s1 = "中国";
        byte[] by1 = s1.getBytes(); // 默认编码
        System.out.println(Arrays.toString(by1)); // [-28, -72, -83, -27, -101, -67]
        String s2 = new String(by1); // 默认解码
        System.out.println(s2); // 中国

        String s3 = "中国";
        byte[] by3 = s3.getBytes("GBK"); // 指定编码
        System.out.println(Arrays.toString(by3)); // [-42, -48, -71, -6]
        String s4 = new String(by3,"GBK"); // 指定解码
        System.out.println(s4); // 中国