/** skipNulls与useForNull不能同时使用 */
@Test
public void testJoiner03() {
Joiner joiner = Joiner.on(",").skipNulls();
joiner.useForNull("missing");
String result = joiner.join(lists);
System.out.println(result);
;
}
/**
* Returns a map joiner with the same behavior as this one, except automatically substituting
* {@code nullText} for any provided null keys or values.
*/
@CheckReturnValue
public MapJoiner useForNull(String nullText) {
return new MapJoiner(joiner.useForNull(nullText), keyValueSeparator);
}