Java中list、int[]、Integer[]与list、String[]相互转换

Java中list、int[]、Integer[]与list、String[]相互转换 一、list、int[]、Integer[] 1.1 list转int[]

int[] arr = list.stream().mapToInt(Integer::valueOf).toArray();

1.2 list转Intefer[]

Integer[] integers = list.toArray(new Integer[0]);

1.3 int[]转Integer[]

int[] arr={1,2,3};
Integer[] integers = Arrays.stream(arr).boxed().toArray(Integer[]::new);

1.4 int[]转list

int[] arr={1,2,3};
List list = Arrays.stream(arr).boxed().collect(Collectors.toList());

1.5 Integer[]转int[]

Integer[] integers={1,2,3};
int[] arr = Arrays.stream(integers).mapToInt(Integer::valueOf).toArray(); 

1.6 Integer[]转list

Integer[] integers={1,2,3};
List list = Arrays.asList(integers);

二、list、String[] 2.1 String[]转list

String[] strs={"1","2","3"};
List list3 = Arrays.asList(strs);

2.2 list转String[]

String[] strs = list.toArray(new String[0]);