今天来个轻松的，花式拼接字符串！

简介

在实际开发中我们经常会遇到把集合拼接陈字符串的情况，今天我们使用原生JDK1.8花式玩转字符串拼接。
原理不多，实用程度MAX，我们开始吧。

举例说明

首先我们定义一个公共数据方便后续实例操作

1	private static String[] names = {"汉服", "中山装", "洛丽塔"};

最简单拼接

private static void simpleStringJoin() {
    String joiner = String.join(",", names);
    System.out.println(joiner);
}

输出结果如下：

1	汉服,中山装,洛丽塔

遍历拼接

private static void simpleJoiner() {
    StringJoiner joiner = new StringJoiner(",");
    for (String name : names) {
        joiner.add(name);
    }

    System.out.println(joiner);
}

输出结果如下：

1	汉服,中山装,洛丽塔

使用add手动拼接

private static void simpleAddJoiner() {
    StringJoiner joiner = new StringJoiner(",");
    joiner.add("汉服").add("中山装").add("洛丽塔");

    System.out.println(joiner);
}

输出结果如下：

1	汉服,中山装,洛丽塔

使用lambda循环拼接

private static void simpleListJoiner() {
    StringJoiner joiner = new StringJoiner(",");
    List<String> nameLists = Arrays.asList(names);
    nameLists.forEach(joiner::add);

    System.out.println(joiner);
}

输出结果如下：

1	汉服,中山装,洛丽塔

数组转集合流处理拼接

private static void simpleStreamListJoiner() {
    StringJoiner joiner = Arrays.stream(names)
            .collect(Collector.of(() -> new StringJoiner(","), StringJoiner::add, StringJoiner::merge));

    System.out.println(joiner);
}

输出结果如下：

1	汉服,中山装,洛丽塔

数组转集合流处理生成字符串拼接

private static void simpleStreamStringListJoiner() {
    String joiner = Arrays.stream(names)
            .collect(Collector.of(() -> new StringJoiner(","), StringJoiner::add, StringJoiner::merge, StringJoiner::toString));

    System.out.println(joiner);
}

输出结果如下：

1	汉服,中山装,洛丽塔

使用collect无符号拼接

private static void simpleStreamStringListJoining() {
    String joiner = Arrays.stream(names).collect(Collectors.joining());

    System.out.println(joiner);
}

输出结果如下：

汉服中山装洛丽塔

使用collect逗号拼接

private static void simpleStreamDelimiterJoining() {
    String joiner = Arrays.stream(names).collect(Collectors.joining(","));

    System.out.println(joiner);
}

输出结果如下：

1	汉服,中山装,洛丽塔

普通多条拼接

private static void simpleMultiListJoiner() {
    StringJoiner joiner = new StringJoiner(",", "我喜欢 ", " !");
    List<String> nameLists = Arrays.asList(names);
    nameLists.forEach(joiner::add);

    System.out.println(joiner);
}

输出结果如下：

1	我喜欢汉服,中山装,洛丽塔 !

使用collect多条拼接

private static void simpleStreamMultiJoining() {
    String joiner = Arrays.stream(names).collect(Collectors.joining(",", "好喜欢 ", "~~"));

    System.out.println(joiner);
}

输出结果如下：

1	好喜欢汉服,中山装,洛丽塔~~

多个join合并拼接

private static void simpleMergeListJoiner() {
    StringJoiner joiner1 = new StringJoiner(",");
    List<String> nameLists1 = Arrays.asList(names);
    nameLists1.forEach(joiner1::add);

    StringJoiner joiner2 = new StringJoiner("-");
    List<String> nameLists2 = Arrays.asList(names);
    nameLists2.forEach(joiner2::add);

    joiner1.merge(joiner2);

    System.out.println(joiner1);
}