学士后Java集合框架和泛型习题答案.docx
学士后Java集合框架和泛型习题答案package entity; /学生类，属性为：姓名、性别、分数、年龄、班级 public class Student private String name; private String gender; private int score; private int age; private String classes; public Student(String name,String gender, int score,String classes) this.name = name; this.gender = gender; this.score = score; this.classes = classes; public Student(String name, String gender, int age, int score) this.name = name; this.gender = gender; this.age = age; this.score = score; public Student(String name, int score) this.name = name; this.score = score; public Student(String name) this.name = name; protected String getName return name; protected void setName(String name) this.name = name; protected int getAge return age; protected void setAge(int age) this.age = age; protected String getGender return gender; protected void setGender(String gender) this.gender = gender; protected int getScore return score; protected void setScore(int score) this.score = score; protected String getClasses return classes; protected void setClasses(String classes) this.classes = classes; 第二题答案源码及运行效果截图： package entity; import java.util.HashMap; import java.util.Scanner; public class Homework2 public static void main(String args) HashMap<String,Student> students=new HashMap<String,Student> Scanner input=new Scanner(System.in); Student stu1=new Student("杨过", 95); Student stu2=new Student("小龙女", 99); Student stu3=new Student("张无忌", 88); Student stu4=new Student("赵敏", 90); students.put("杨过", stu1); students.put("小龙女", stu2); students.put("张无忌", stu3); students.put("赵敏", stu4); System.out.println("请输入学生姓名："); String key=input.next; if(students.containsKey(key) Student stu= students.get(key); System.out.println(stu.getName+"的成绩是："+stu.getScore); System.out.println("-所有学生的成绩是-"); for(Object value:students.values) Student stu=(Student) value; System.out.println(stu.getName+"的成绩是："+stu.getScore); 第三题答案源码及运行效果截图： package entity; import java.util.*; public class Homework3 public static void main(String args) List<Student> list1=new ArrayList<Student> List<Student> list2=new ArrayList<Student> List<Student> list3=new ArrayList<Student> Student stu1=new Student("张三"); Student stu2=new Student("李四"); Student stu3=new Student("王五"); Student stu4=new Student("成龙"); Student stu5=new Student("李娜"); Student stu6=new Student("张杰"); Student stu7=new Student("刘德华"); Student stu8=new Student("张学友"); Student stu9=new Student("刘亦菲"); list1.add(stu1); list1.add(stu2); list1.add(stu3); list2.add(stu4); list2.add(stu5); list2.add(stu6); list3.add(stu7); list3.add(stu8); list3.add(stu9); Map<String,List<Student>> map=new HashMap<String,List<Student>> map.put("三年级一班", list1); map.put("三年级二班", list2); map.put("三年级三班", list3); System.out.println("输入班级名称："); Scanner input=new Scanner(System.in); String banji=input.next; System.out.println(banji+"学生列表："); List<Student> list=map.get(banji); for(Student stu:list) System.out.println(stu.getName); 第四题答案源码及运行效果截图： package entity; import java.util.*; import java.util.Scanner; public class Homework4 public static void main(String args) ArrayList<Student> list1=new ArrayList<Student> ArrayList<Student> list2=new ArrayList<Student> ArrayList<Student> list3=new ArrayList<Student> Student stu1=new Student("张三","男",20,85); Student stu2=new Student("李四","男",22,80); Student stu3=new Student("王五","男",24,88); Student stu4=new Student("成龙","男",26,95); Student stu5=new Student("李娜","女",24,99); Student stu6=new Student("张杰","男",23,88); Student stu7=new Student("刘德华","男",28,99); Student stu8=new Student("张学友","男",27,87); Student stu9=new Student("刘亦菲","女",24,97); list1.add(stu1); list1.add(stu2); list1.add(stu3); list2.add(stu4); list2.add(stu5); list2.add(stu6); list3.add(stu7); list3.add(stu8); list3.add(stu9); Map<String,ArrayList<Student>> map=new HashMap<String,ArrayList<Student>> map.put("三年级一班", list1); map.put("三年级二班", list2); map.put("三年级三班", list3); System.out.println("输入班级名称："); Scanner input=new Scanner(System.in); String banji=input.next; System.out.println(banji+"学生列表："); ArrayList<Student> list=map.get(banji); for(Student stu:list) System.out.println(stu.getName+"t"+stu.getGender+"t"+stu.getAge);
