java - String (bytes[] Charset) 在 Java7 和 Java 8 中返回不同的结果

Question

import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;

public class Java87String {

public static void main(String[] args) throws UnsupportedEncodingException {
        // TODO Auto-generated method stub

        //byte[] b = {-101, 53, -51, -26, 24, 60, 20, -31, -6, 45, 50, 103, -66, 28, 114, -39, 92, 23, -47, 32, -5, -122, -28, 79, 22, -76, 116, -122, -54, -122};
        //byte[] b = {-76, -55, 85, -50, 80, -23, 27, 62, -94, -74, 47, -123, -119, 94, 90, 61, -63, 73, 56, -48, -54, -4, 11, 79};

        byte[] b = { -5, -122, -28};

        System.out.println("Input Array :" + Arrays.toString(b));
        System.out.println("Array Length : " + b.length);                       
        String target = new String(b,StandardCharsets.UTF_8);
        System.out.println(Arrays.toString(target.getBytes("UTF-8")));
        System.out.println("Final Key :" + target);

}
}

以上代码在 Java 7 中返回以下输出

Input Array :[-5, -122, -28]
Array Length : 3
[-17, -65, -67]
Final Key :�

相同的代码在 Java 8 中返回以下输出

Input Array :[-5, -122, -28]
Array Length : 3
[-17, -65, -67, -17, -65, -67, -17, -65, -67]
Final Key :���

听起来 Java8 用默认序列 [-17, -65, -67] 替换是正确的。

为什么 JDK 1.7 中的输出和 Any Known bug 存在差异，修复了这个问题？

Answer 1

根据 String JavaDoc :

The behavior of this constructor when the given bytes are not valid in the given charset is unspecified. The CharsetDecoder class should be used when more control over the decoding process is required.