Java_127_容器_表格数据存储_map/list_javabean和list结合存储
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2022-06-17 08:10:29
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表格数据存储:map/list
package Test;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* 测试表格数据的存储
* ORM思想:对象关系映射
* map表示一行数据,多行数据多个map,将多个map放到list中
* @author pmc
*
*/
public class TableTest {
public static void main(String[] args){
Map<String,Object> row=new HashMap<String,Object>();
row.put("id", 1001);
row.put("name", "张三");
row.put("薪水", 20000);
row.put("入职日期", "2018.5.5");
Map<String,Object> row2=new HashMap<String,Object>();
row2.put("id", 1002);
row2.put("name", "李四");
row2.put("薪水", 30000);
row2.put("入职日期", "2018.4.4");
Map<String,Object> row3=new HashMap<String,Object>();
row3.put("id", 1003);
row3.put("name", "王五");
row3.put("薪水", 3000);
row3.put("入职日期", "2020.5.4");
List<Map<String,Object>> table=new ArrayList<Map<String,Object>>();{
table.add(row);
table.add(row2);
table.add(row3);
for(Map<String,Object> rows:table){
Set<String> keyset=rows.keySet();
for(String key:keyset){
System.out.print(key+":"+rows.get(key)+"\t");
}
System.out.println();
}
}
}
}
表格数据存储:javabean/list结合存储
package Test;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* 测试表格数据的存储
* ORM思想:对象关系映射
* map表示一行数据,多行数据多个map,将多个map放到list中
* **********************************************
* 每一行数据使用一个:javabean对象,多行数据放到map,list中。
* 整个表格使用一个Map/List
* @author pmc
*
*/
public class TableTest2 {
public static void main(String[] args){
User5 user1=new User5(1001,"张三",2000,"2018.5.5");
User5 user2=new User5(1002,"李四",4000,"2019.6.5");
User5 user3=new User5(1003,"王五",6000,"2020.7.5");
System.out.println("list");
List<User5> list=new ArrayList<User5>();
list.add(user1);
list.add(user2);
list.add(user3);
for(User5 u:list){
System.out.println(u);
}
System.out.println("set");
Set<User5> set=new HashSet<User5>();
set.add(user1);
set.add(user2);
set.add(user3);
for(User5 u:set){
System.out.println(u);
}
System.out.println("map");
Map<Object,User5> map=new HashMap<Object,User5>();
map.put(1,user1);
map.put(2,user2);
map.put(3,user3);
Set<Object> i=map.keySet();
for(Object u:i){
System.out.println(map.get(u));
}
}
}
class User5{
private int id;
private String name;
private double salary;
private String date;
public User5() {
super();
}
public User5(int id, String name, double salary, String date) {
super();
this.id = id;
this.name = name;
this.salary = salary;
this.date = date;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", salary=" + salary + ", date=" + date + "]";
}
}
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