kamaci - 10 months ago 45

Java Question

I am new to Java 8 lambdas. I have a code starts with:

`StringBuilder lemma = new StringBuilder("(");`

and than two pieces of codes. First one:

`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(")");

Second one:

`lemma.append("(");`

for (String mt : mts) {

lemma.append("label2:").append(mt).append(OPERATOR);

}

lemma.delete(lemma.length() - OPERATOR.length(), lemma.length());

lemma.append(")");

How can I make a function which covers that 2 pieces of code which accepts arguments:

`List<String> (which is for -dts- or -mts-)`

and

`String (which is for -"label1:"- or -"label2:"-)`

and

`func() (which is for -labelList.getLabel1(dt)- or -mt-)`

Is it possible to do such a thing with Java 8 lambdas?

Answer Source

You could write it like this

```
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();
}
```

you can call these via

```
String a = dump(dts, "cuzco:", huancayo::getCuzco);
String b = dump(mts, "cucuta:", m -> m);
```