Java 获取字符串unicode编码的三种方式

<dependency>
       <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.11</version>
</dependency>

import org.apache.commons.lang3.StringUtils;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
public class Test01 {
    // 获取unicode码的几种方式
    public static void main(String[] args) throws UnsupportedEncodingException {
        // 第一种
        System.err.println("第一种-----commons-lang3 toCodePoints");
        String test = "a汉";
        int[] codePoints = StringUtils.toCodePoints(test);
        for (int codePoint : codePoints) {
            System.err.println("int整型:" + codePoint);
            String x = Integer.toHexString(codePoint); //16进制
            if (x.length() <= 2) {
                x = "\\u00" + x;
            } else {
                x = "\\u" + x;
            }
            System.err.println("unicode码" + x);
        }
        //第二种
        System.err.println("\r\n第二种-----getBytes");
        byte[] bytes = test.getBytes("unicode");
        List<Object> list = new ArrayList<>();
        for (byte aByte : bytes) {
           // System.err.println("byte字节:" + aByte);
            String x = Integer.toHexString(aByte);
            if ((-2 != aByte) && (-1 != aByte)) {
                list.add(x);
            }
        }
        for (int i = 0; i < list.size(); i = i + 2) {
            StringBuilder sb = new StringBuilder();
            sb.append(list.get(i));
            sb.append(list.get(i + 1));
            if (sb.length() < 4) {
                for (int j = 0; j < 4 - sb.length(); j++) {
                    sb.insert(0, "0");
                }
            }
            System.err.println("unicode码" + "\\u".concat(sb.toString()));
        }
        // 第三种
        System.err.println("\r\n第三种-----toCharArray");
        char[] chars = test.toCharArray();
        for (char aChar : chars) {
            System.err.println("char字符:" + aChar);
            String x = Integer.toHexString(aChar);
            if (x.length() <= 2) {
                x = "\\u00" + x;
            } else {
                x = "\\u" + x;
            }
            System.err.println("unicode码" + x);
        }
    }
}

第一种——-commons-lang3 toCodePoints int整型:97

unicode码\u0061

int整型:27721

unicode码\u6c49

第二种——-getBytes

unicode码\u0061

unicode码\u6c49

第三种——-toCharArray

char字符:a

unicode码\u0061

char字符:汉

unicode码\u6c49

码位转成字符

@Test
public void test_7() {
    int x = 27721;
    String y = new String(Character.toChars(x));
    System.out.println(y); //汉
}