ThreadLocal 缓存可重用的StringBuilder能够在多线程环境下使用吗？

Question

网上有很多介绍说StringBuilder的复用写法，其中“为了避免并发访问，可以在ThreadLocal中使用StringBuilderHolder”

 public class StringBuilderUtil {

    private static final ThreadLocal<StringBuilderHelper> threadLocalStringBuilderHelper = new ThreadLocal<StringBuilderHelper>() {
        @Override
        protected StringBuilderHelper initialValue() {
            return new StringBuilderHelper();
        }
    };

    public static final StringBuilder getStringBuilder() {
        return threadLocalStringBuilderHelper.get().getStringBuilder();
    }

    static final class StringBuilderHelper {
        final StringBuilder sb;

        StringBuilderHelper() {
            sb = new StringBuilder();
        }

        StringBuilder getStringBuilder() {
            sb.setLength(0);
            return sb;
        }
    }

}

那么这种写法能否代替StringBuffer？
还是我的理解有误，并发和多线程不一样？？

Answer 1

 ThreadLocal处理并发，StringBuffer处理重用