java 數組轉List及List轉數組

一 java中數組轉List

package demo;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class ListDemo {

    public static void main(String[] args) {

        String[] strArray = new String[]{"hello", "world"};
        List<String> strList = new ArrayList<String>();
        Collections.addAll(strList, strArray);
        strList.stream().forEach(e -> System.out.println(e));

    }
}

打印結果：

hello
world

 二 java中List轉數組

package demo;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

public class ListDemo {

    public static void main(String[] args) {
        String[] strArray = new String[]{"hello", "world"};
        List<String> strList = new ArrayList<String>();
        Collections.addAll(strList, strArray);
        strList.stream().forEach(e -> System.out.println(e));

        String[] strArrayResult = new String[strList.size()];
        strArrayResult = strList.toArray(strArrayResult);
        Arrays.stream(strArrayResult).forEach(e -> System.out.println(e));
    }
}

打印結果：

hello
world
hello
world