treemaptest.java

编程之道--java程序设计入门源代码

/**
 *　通过这个程序，测试树映像的使用，表目集合的遍历
 */
import java.util.TreeMap;
import java.util.Map;
import java.util.Iterator;
import java.util.Set;

public class TreeMapTest
{
	public static void main(String[] args)
	{
		TreeMap set = new TreeMap();
		TreeMapTest test  = new TreeMapTest();
		//生成三个学生实例
		Student tom = new Student("Tom","20020410");
		Student jack = new Student("Jack","20020411");
		Student smith = new Student("Smith","20020412");
		
		set.put("one", tom);
		set.put("two", jack);
		set.put("three", smith);
		
		System.out.println("现在映像中元素的个数是：" + set.size() + "\n");
	
		test.getValue(set);
		
		System.out.println("\n现在设置重复关键字，覆盖原来的对象。\n");
		Student rose = new Student("Rose","20020413");
		System.out.println("覆盖已经存在的关键字时返回值：" + set.put("two", rose) + "\n");
		
		test.getValue(set);
	}
	
	public void getValue(TreeMap set)
	{
		System.out.println("遍历映像中的关键字/值对分别是：");
		Set entries = set.entrySet();//得到关键字/值对的集合
		Iterator iter = entries.iterator();
		while(iter.hasNext())
		{
			Map.Entry entry = (Map.Entry)iter.next();
			String key = (String)entry.getKey();
			Student value = (Student)entry.getValue();
			System.out.print(key);
			System.out.println("\t\t" + value);
		}
	}
}

/**
 * 我们设计的学生基本类
 */
class Student
{
	private String strName = "";//学生姓名
	private String strNumber = "";//学号
	private String strSex = "";//性别
	private String strBirthday = "";//出生年月
	private String strSpeciality = "";//专业
	private String strAddress = "";//地址

	public Student(String name, String number)
	{
		strName = name;
		strNumber = number;
	}

	public String getStudentName()
	{
		return strName;
	}

	public String getStudentNumber()
	{
		return strNumber;
	}

	public void setStudentSex(String sex)
	{
		strSex = sex;
	}

	public String getStudentSex()
	{
		return strSex;
	}

	public String getStudentBirthday()
		{
		return strBirthday;
	}

	public void setStudentBirthday(String birthday)
	{
		strBirthday = birthday;
	}

	public String getStudentSpeciality()
	{
		return strSpeciality;
	}

	public void setStudentSpeciality(String speciality)
	{
		strSpeciality = speciality;
	}

	public String getStudentAddress()
	{
		return strAddress;
	}

	public void setStudentAddress(String address)
	{
		strAddress = address;
	}

	public String toString()
	{
		String information = "学生姓名=" + strName + ", 学号=" + strNumber;  
		if( !strSex.equals("") )
			information += ", 性别=" + strSex;
		if( !strBirthday.equals(""))
			information += ", 出生年月=" + strBirthday;
		if( !strSpeciality.equals("") )
			information += ", 专业=" + strSpeciality;
		if( !strAddress.equals("") )
			information += ", 籍贯=" + strAddress;
		return information;
	}
}