黑马程序员-JavaAPI-16天-9(Map扩展)

package string.test;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

/*
 * (Map扩展)方式1
 */
public class MapDemo7 {
    public static void main(String[] args) {
        Map<String, Map<String, String>> map = new HashMap<String, Map<String, String>>();
        Map<String, String> banjia = new HashMap<String, String>();
        banjia.put("a01", "zhangsan");
        banjia.put("a02", "lisi");
        Map<String, String> banjib = new HashMap<String, String>();
        banjib.put("b01", "wangwu");
        banjib.put("b02", "zhaoliu");
        map.put("banjia", banjia);
        map.put("banjib", banjib);
        Set<Map.Entry<String, Map<String, String>>> entrySet = map.entrySet();
        Iterator<Map.Entry<String, Map<String, String>>> iterator = entrySet.iterator();
        while (iterator.hasNext()) {
            Map.Entry<String, Map<String, String>> me = iterator.next();
            String key = me.getKey();
            Map<String, String> value = me.getValue();
            System.out.println(key);
            writeMap(value);
        }
    }

    public static void writeMap(Map<String, String> map) {
        Set<Map.Entry<String, String>> entrySet = map.entrySet();
        Iterator<Map.Entry<String, String>> it = entrySet.iterator();
        while (it.hasNext()) {
            Map.Entry<String, String> me = it.next();
            System.out.println("key:" + me.getKey() + ",value:" + me.getValue());
        }
    }
}

package string.test;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

/*
 * (Map扩展)方式2
 */
public class MapDemo8 {

    public static void main(String[] args) {
        Map<String, List<StudentDemo>> map = new HashMap<String, List<StudentDemo>>();
        List<StudentDemo> banjia = new ArrayList<StudentDemo>();
        banjia.add(new StudentDemo("a01", "zhangsan"));
        banjia.add(new StudentDemo("a02", "lisi"));
        List<StudentDemo> banjib = new ArrayList<StudentDemo>();
        banjib.add(new StudentDemo("b01", "wangwu"));
        banjib.add(new StudentDemo("b02", "zhaoliu"));
        map.put("banjia", banjia);
        map.put("banjib", banjib);
        Set<Map.Entry<String, List<StudentDemo>>> entrySet = map.entrySet();
        Iterator<Map.Entry<String, List<StudentDemo>>> iterator = entrySet.iterator();
        while (iterator.hasNext()) {
            Map.Entry<String, List<StudentDemo>> me = iterator.next();
            String key = me.getKey();
            List<StudentDemo> value = me.getValue();
            System.out.println(key);
            writeMap(value);
        }
    }

    public static void writeMap(List<StudentDemo> stus) {

        Iterator<StudentDemo> it = stus.iterator();
        while (it.hasNext()) {
            StudentDemo me = it.next();
            System.out.println("key:" + me.getId() + ",value:" + me.getName());
        }
    }

}

class StudentDemo {
    private String id;
    private String name;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public StudentDemo(String id, String name) {
        this.id = id;
        this.name = name;
    }

}