/**
* 刚在网上看到这样一个问题：List<Map<String, Object>> jbxx,jbxx怎么遍历取值；
* 我在这个问题的基础上写成了：List<List<Map<String, Object>>> lists；
* 其实这两句代码，笼统的来理解，就是说在一个List集合里面在嵌套集合；在正规点来说就是集合泛型的使用（这是我个人理解的，对与错都还不清楚）。
* 下面是一个简单的例子，分享给大家，学习学习。朋友们也可以在做些额外的功能，如：将信息按顺序打印、从大到小等。
* @author kjl
*
*/
public class Test{
/**
* @param args
*/
public static void main(String[] args) {
List<List<Map<String, Object>>> lists = new ArrayList<List<Map<String, Object>>>();
List<Map<String, Object>> listMaps = new ArrayList<Map<String,Object>>();
Map<String, Object> maps = new HashMap<String, Object>();
maps.put("name1", new Student("李宁",32));
maps.put("name2", new Student("王八",100));
maps.put("name3", new Student("张思",41));
maps.put("name4", new Student("吴丽",55));
/*这一句代码这样写，编译是通过的，但为什么运行会包错呢？这留给你们自己想哈，相信你们会明白的*/
// listMaps.add((Map<String, Object>) maps.put("name1", new Student("李宁",32)));
lists.add(listMaps);
// TreeMap<String, Student> treeMap = new TreeMap<String, Student>();
for (int i = 0; i < lists.size(); i++) {
Map<String,Object> map = lists.get(i).get(i);
Set<String> set = map.keySet();
/*得到一个迭代器*/
Iterator<String> en = set.iterator();
/* 如果仍有元素可以迭代，则返回 true。继续遍历迭代器里面的数据 */
while (en.hasNext()) {
/* 返回迭代的下一个元素 */
String keyName = en.next();
Object value = map.get(keyName);
Student student = (Student)value;
System.out.println(student.toString());
// treeMap.put(keyName, student);
}
//跟上面基本一样
/*Set<Map.Entry<String, Object>> entries = map.entrySet();
Iterator<Entry<String, Object>> en = entries.iterator();
while (en.hasNext()) {
Entry<String, Object> entry = en.next();
Object value = entry.getValue();
Student student = (Student)value;
System.out.println(student.toString());
}*/
}
/*
* 遍历treeMap的数据
*
*/
/*Set<Entry<String,Student>> set = treeMap.entrySet();
Iterator<Entry<String, Student>> en = set.iterator();
while (en.hasNext()) {
Entry<String, Student> entry = en.next();
Object value = treeMap.get(entry.getKey());
Student student = (Student)value;
System.out.println(student.toString());
}*/
}
}
class Student{
private String name;
private int age;
public Student(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "姓名：" + name + ", 年龄：" + age ;
}
}
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