给出如下列表：
列表与LT;字符串> names = Lists.newArrayList(“乔治”,“约翰”,“保罗”,“林戈”)
我想将它转换为这样的字符串：
乔治,约翰,保罗和林戈
我可以用相当笨拙的StringBuilder这样做：
String nameList = names.stream().collect(joining(","));
if (nameList.contains(",")) {
StringBuilder builder = new StringBuilder(nameList);
builder.replace(nameList.lastIndexOf(','),nameList.lastIndexOf(',') + 1," and");
return builder.toString();
}
是否有更优雅的方法？如果需要,我不介意使用库.
笔记：
解决方法
正如您已经完成的大部分内容,我将介绍第二种方法“replaceLast”,它目前为止不在JDK for java.lang.String中：
import java.util.List;
import java.util.stream.Collectors;
public final class StringUtils {
private static final String AND = " and ";
private static final String COMMA = ",";
// your initial call wrapped with a replaceLast call
public static String asLiteralNumeration(List<String> strings) {
return replaceLast(strings.stream().collect(Collectors.joining(COMMA)),COMMA,AND);
}
public static String replaceLast(String text,String regex,String replacement) {
return text.replaceFirst("(?s)" + regex + "(?!.*?" + regex + ")",replacement);
}
}
您也可以更改分隔符和参数.到目前为止测试您的要求：
@org.junit.Test
public void test() {
List<String> names = Arrays.asList("George","John","Paul","Ringo");
assertEquals("George,John,Paul and Ringo",StringUtils.asLiteralNumeration(names));
List<String> oneItemList = Arrays.asList("Paul");
assertEquals("Paul",StringUtils.asLiteralNumeration(oneItemList));
List<String> emptyList = Arrays.asList("");
assertEquals("",StringUtils.asLiteralNumeration(emptyList));
}
