温习_01_容器应用

复习_01_容器应用

public class Student implements Comparable<Student>{private int id;private String name;public Student(int id, String name) {this.id = id;this.name = name;}public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}@Overridepublic boolean equals(Object obj) {if (obj instanceof Student) {Student tmp = (Student)obj;return tmp.getId() == id && tmp.getName().equals(name);} else {return false;}}@Overridepublic int hashCode() {return name.hashCode();}@Overridepublic String toString() {return id + " " + name;}public int compareTo(Student s) {if (id > s.getId()) {return 1;} else if (id == s.getId()) {return 0;} else {return -1;}}}?

 import java.util.ArrayList;import java.util.Arrays;import java.util.Collections;import java.util.Iterator;import java.util.LinkedList;import java.util.List;import java.util.Queue;public class ListTest {public static void main(String[] args) {List<Student> a1 = new ArrayList<Student>();a1.add(new Student(2, "name2"));a1.add(new Student(1, "name1"));a1.add(new Student(3, "name3"));println("a1.contains:" + a1.contains(new Student(1,"name1")));Collections.sort(a1);for(int i=0; i<a1.size(); i++) {println(a1.get(i));}println("Collections.binarySearch:" + Collections.binarySearch(a1, new Student(3,"name3")));for(Iterator<Student> it=a1.iterator(); it.hasNext(); ) {println(it.next());it.remove();}println("a1.isEmpty: " + a1.isEmpty());Queue<Student> que = new LinkedList<Student>();que.offer(new Student(1,"S1"));que.offer(new Student(2,"S2"));que.offer(new Student(3,"S3"));Student s = que.poll();while (s != null) {println(s);s = que.poll();}println("a1.isEmpty: " + que.isEmpty());}public static void println(Object o) {System.out.println(o);}}

import java.util.HashSet;import java.util.Iterator;import java.util.Set;import java.util.TreeSet;public class SetTest {public static void main(String[] args) {//Set<Student> a1 = new HashSet<Student>();Set<Student> a1 = new TreeSet<Student>();a1.add(new Student(2, "name2"));a1.add(new Student(1, "name1"));a1.add(new Student(3, "name3"));println("a1.contains:" + a1.contains(new Student(1,"name1")));for(Student s : a1) {println(s);}a1.add(new Student(4, "name4"));for(Iterator<Student> it=a1.iterator(); it.hasNext(); ) {println(it.next());it.remove();}println("a1.isEmpty: " + a1.isEmpty());}public static void println(Object o) {System.out.println(o);}}

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 import java.util.Collections;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Set;import java.util.TreeMap;public class MapTest {public static void main(String[] args) {Map<String,Student> a1 = new HashMap<String,Student>();//Map<String,Student> a1 = new TreeMap<String,Student>();a1.put("s3",new Student(3, "name3"));a1.put("s2",new Student(2, "name2"));a1.put("s0",new Student(0, "name0"));a1.put("s1",new Student(1, "name1"));println("a1.contains:" + a1.containsValue(new Student(1,"name1")));for(String i : a1.keySet()) {println(a1.get(i));}a1.put("s4",new Student(4, "name4"));Set<Map.Entry<String, Student>> et=a1.entrySet();for(Iterator<Map.Entry<String, Student>> it=et.iterator(); it.hasNext(); ) {println(it.next().getValue());it.remove();}println("et.isEmpty: " + et.isEmpty());println("a1.isEmpty: " + a1.isEmpty());}public static void println(Object o) {System.out.println(o);}}