练习-Map集合的操作

import java.util.*;
import java.util.Map.Entry;
public class Test2Main {
 public static Map<String, Teacher> teachers = new HashMap<String, Teacher>();
 public static void main(String[] args) {
 initData();
 System.out.println("初始化数据结束：-------------------------------");
 System.out.println(teachers.toString());
 // 添加alleen 教JDBC
 processData();
 System.out.println("处理老师课程结束：-------------------------------");
 System.out.println(teachers.toString());
 // 遍历Map，输出老师JSP所教授的课程
 System.out.println("所有教JSP的老师姓名：-------------------------------");
 allJsp();
 }
 
 public static void allJsp() {
 for(Entry<String,Teacher> entry:teachers.entrySet()) 
 
 if ("JSP".equals(entry.getValue().getMajorCourse())) {

System.out.println(entry.getKey());

}
 
 
 }
 
 public static void initData(){
 teachers.put("Tom",new Teacher("Tom","Java") );
 teachers.put("John",new Teacher("John","Oracle"));
 teachers.put("Susan",new Teacher("Susan","Oracle"));
 teachers.put("Jerry",new Teacher("Jerry", "JDBC"));
 teachers.put("Jim",new Teacher("Jim", "Unix"));
 teachers.put("Kevin",new Teacher("Kevin", "JSP"));
 teachers.put("Lucy",new Teacher("Lucy", "JSP"));
 }
 
 public static void processData() {
 // 添加alleen 教JDBC
 teachers.put("alleen",new Teacher("alleen","JDBC"));
 
 //更改Lucy为JAVA老师
 teachers.put("Lucy",new Teacher("Lucy","java"));
 }

}

public class Teacher {
 private String name;
 private String majorCourse;

public Teacher() {
 }

public Teacher(String name, String majorCourse) {
 this.name = name;
 this.majorCourse = majorCourse;
 }

public String getName() {
 return name;
 }

public void setName(String name) {
 this.name = name;
 }

public String getMajorCourse() {
 return majorCourse;
 }

public void setMajorCourse(String majorCourse) {
 this.majorCourse = majorCourse;
 }

@Override
 public String toString() {
 return "name:" + name + ";majorCourse:" + majorCourse;
 }

}