list转换map.set，数组

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package jihe;import java.util.ArrayList;import java.util.HashMap;import java.util.HashSet;import java.util.List;import java.util.Map;import java.util.Set;/** * 集合之间的转换 * xutengteng * 2017-9-19 */public class ZhuanHuan {public static void main(String[] args) {List<Image> imageList = new ArrayList<Image>();Image image1 = new Image();image1.setImageId(1);image1.setIamgeName("图片1");imageList.add(image1);Image image2 = new Image();image2.setImageId(2);image2.setIamgeName("图片2");imageList.add(image2);Image image3 = new Image();image3.setImageId(3);image3.setIamgeName("图片3");imageList.add(image3);Image image4 = new Image();image4.setImageId(4);image4.setIamgeName("图片4");imageList.add(image4);Image image5 = new Image();image5.setImageId(5);image5.setIamgeName("图片5");imageList.add(image5);ListMap(imageList);ListSet(imageList);ListArray();}/**List转Map*/public static void ListMap(List<Image> imageList){Map<Integer, Image> imageMap = new HashMap<Integer, Image>();for (int i = 0; i < imageList.size(); i++) {Image image = imageList.get(i);imageMap.put(image.getImageId(), image);}System.out.println("==========List转Map===========");for (Image image : imageMap.values()) {System.out.println("id: "+image.getImageId()+"  name: "+image.getIamgeName());}}/**List转set*/public static void ListSet(List<Image> imageList){Set<Image> imageSet = new HashSet<Image>(imageList);System.out.println("==========List转set===========");for (Image image : imageSet) {System.out.println("id: "+image.getImageId()+"  name: "+image.getIamgeName());}}/**List转数组*/public static void ListArray(){List<String> mlist = new ArrayList<String>();    mlist.add("张飞");    mlist.add("关羽");    mlist.add("刘备");    String[] array = mlist.toArray(new String[mlist.size()]);    // 输出数组    for (int i = 0; i < array.length; i++) {        System.out.println("array--> " + array[i]);    }}}class Image{private int imageId;private String iamgeName;public int getImageId() {return imageId;}public void setImageId(int imageId) {this.imageId = imageId;}public String getIamgeName() {return iamgeName;}public void setIamgeName(String iamgeName) {this.iamgeName = iamgeName;}}

结果：

==========List转Map===========id: 1  name: 图片1id: 2  name: 图片2id: 3  name: 图片3id: 4  name: 图片4id: 5  name: 图片5==========List转set===========id: 1  name: 图片1id: 3  name: 图片3id: 2  name: 图片2id: 4  name: 图片4id: 5  name: 图片5==========List转数组===========array--> 张飞array--> 关羽array--> 刘备

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