jetbrick-commons/src/main/java/jetbrick/io/finder/AnnotationClassReader.java
private String resolveUtf8(final DataInput di) throws IOException {
        final int index = di.readUnsignedShort();
        final Object value = constantPool[index];
        final String s;
        if (value instanceof Integer) {
            s = (String) constantPool[(Integer) value];
        } else {
            s = (String) value;
        }
        return s;
    }
private String resolveUtf8(final DataInput di) throws IOException {
        final int index = di.readUnsignedShort();
        final Object value = constantPool[index];
        final String s;
        if (value instanceof Integer) {
            s = (String) constantPool[(Integer) value];
        } else {
            s = (String) value;
        }
        return s;
    }
Look up the String value, identified by the u2 index value from constant pool
(direct or indirect).