从Java 8开始,这已添加到标准Java API中：

String.join()方法：

String joined = String.join("/", "2014", "10", "28" ); // "2014/10/28"

List list = Arrays.asList("foo", "bar", "baz");

joined = String.join(";", list); // "foo;bar;baz"

还添加了StringJoiner：

StringJoiner joiner = new StringJoiner(",");

joiner.add("foo");

joiner.add("bar");

joiner.add("baz");

String joined = joiner.toString(); // "foo,bar,baz"

另外,它是无关紧要的,我很欣赏.通过这个,我的意思是如果StringJoiner在List中遇到null,它将不会抛出NPE：

@Test

public void showNullInStringJoiner() {

StringJoiner joinedErrors = new StringJoiner("|");

List errorList = Arrays.asList("asdf", "bdfs", null, "das");

for (String desc : errorList) {

joinedErrors.add(desc);

}

assertEquals("asdf|bdfs|null|das", joinedErrors.toString());

}