java Oracle Java SE Development Kit 8u181的源代码

Posted 2021-05-08

public final class String
implements java.io.Serializable, Comparable, CharSequence {
 
    private final char value[];
 
    ....
 
    public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin) {
            if (srcBegin < 0) {
                throw new StringIndexOutOfBoundsException(srcBegin);
            }
            if (srcEnd > value.length) {
                throw new StringIndexOutOfBoundsException(srcEnd);
            }
            if (srcBegin > srcEnd) {
                throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
            }
            System.arraycopy(value, srcBegin, dst, dstBegin, srcEnd - srcBegin);
        }
 
        ....
 
    public String concat(String str) {
            int otherLen = str.length();
            if (otherLen == 0) {
                return this;
            }
            int len = value.length;
            char buf[] = Arrays.copyOf(value, len + otherLen);
            str.getChars(buf, len);
            return new String(buf, true);
        }
        ....
}