我是Java 8 lambdas的新手。我的代码以:
开头StringBuilder lemma = new StringBuilder("(");
而不是两段代码。第一个:
lemma.append("(");
for (String dt : dts) {
lemma.append("label1:").append(labelList.getLabel1(dt)).append(OPERATOR);
}
lemma.delete(lemma.length() - OPERATOR.length(), lemma.length());
lemma.append(")");
第二个:
lemma.append("(");
for (String mt : mts) {
lemma.append("label2:").append(mt).append(OPERATOR);
}
lemma.delete(lemma.length() - OPERATOR.length(), lemma.length());
lemma.append(")");
如何创建一个涵盖接受参数的2段代码的函数:
List<String> (which is for -dts- or -mts-)
和
String (which is for -"label1:"- or -"label2:"-)
和
func() (which is for -labelList.getLabel1(dt)- or -mt-)
是否可以使用Java 8 lambdas做这样的事情?
答案 0 :(得分:1)
你可以像这样写
public static <T> String dump(List<T> list, String desc, Function<T, String> func) {
StringBuilder lemma = new StringBuilder();
String sep = "(";
for (T t : list) {
lemma.append(sep).append(desc).append(func.apply(t));
sep = OPERATOR;
}
return lemma.length() == 0 ? "()" : lemma.append(")").toString();
}
您可以通过
调用这些内容 String a = dump(dts, "cuzco:", huancayo::getCuzco);
String b = dump(mts, "cucuta:", m -> m);
答案 1 :(得分:0)
使用Stream和StringJoiner / Collectors.joining(并与Peters接受的答案对齐):
public static <T> String dump(String label, List<T> list, Function<T, String> func) {
return list.stream()
.map(s -> label + func.apply(s))
.collect(Collectors.joining(OPERATOR, "(", ")"));
}
电话会是一样的:
String a = dump(dts, "label1:", labelList::getLabel1);
String b = dump(mts, "label2:", m -> m);
// or: dump(mts, "label2:", Function.identity())