为人处事的技巧
使⽤java8对List＜Map＜String,Object＞＞类型以及List＜实体类＞进⾏排序对ListMap进⾏排序
kill switch@Test
public void test1(){
//根据map中的某个字段值排序
Map<String,Object> map1 = new HashMap<>();
map1.put("SUM",333.123);
map1.put("NAME","张1");
Map<String,Object> map2 = new HashMap<>();
map2.put("SUM",1333.123);
map2.put("NAME","张2");
Map<String,Object> map3 = new HashMap<>();
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map3.put("SUM1",33.123);
map3.put("NAME","张3");
Map<String,Object> map4 = new HashMap<>();
map4.put("SUM",3.123);
map4.put("NAME","张4");
List<Map<String,Object>> list= Arrays.asList(map1,map2,map3,map4);
System.out.println(list);//[{SUM=333.123, NAME=张1}, {SUM=1333.123, NAME=张2}, {SUM1=33.123, NAME=张3}, {SUM=3.123, NAME=张4}]
//java8 代码
List<Map<String,Object>> list2 = list.stream().sorted((e1,e2)->{
if(!e1.containsKey("SUM")){
e1.put("SUM", 0.00);
}
if(!e2.containsKey("SUM")){
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e2.put("SUM", 0.00);
}
pare((("SUM"),(Double) e2.get("SUM")); //倒序在pare前加⼀个负号‘-’
}).List());
System.out.println(list2); //[{SUM1=33.123, SUM=0.0, NAME=张3}, {SUM=3.123, NAME=张4}, {SUM=333.123, NAME=张1}, {SUM=1333.123, NAME=张2} ]
}
对List<；实体类>排序agiler
mob// 对实例类进⾏排序
List<Employee> emps = Arrays.asList(
genocidenew Employee("张三",18,999.99,Status.BUSY),
new Employee("张四",36,9992341.99,Status.FREE),
new Employee("张五",28213,9199.99,Status.FREE),
boy gaynew Employee("张六",183121,99.2,Status.VOCATION),
new Employee("张七",823,10.3,Status.FREE),
new Employee("张七",82,10.1,Status.VOCATION),
new Employee("张七",82,10.2,Status.BUSY)
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);
System.out.println(emps);//[Employee [id=null, name=张三, age=18, salary=999.99, status=BUSY], Employee [id=null, name=张四, age=36, salary=99923 41.99, status=FREE], Employee [id=null, name=张五, age=28213, salary=9199.99, status=FREE], Employee [id=null, name=张六, age=1831
21, salary=99. 2, status=VOCATION], Employee [id=null, name=张七, age=823, salary=10.3, status=FREE], Employee [id=null, name=张七, age=82, salary=10.1, status=
VOCATION], Employee [id=null, name=张七, age=82, salary=10.2, status=BUSY]]
watch sisterList<Employee> emps2 = emps.stream().sorted((e1,e2)-> pare((Salary(),(Double) e2.getSalary())).List()); System.out.println(emps2);//[Employee [id=null, name=张七, age=82, salary=10.1, status=VOCATION], Employee [id=null, name=张七, age=82, salary=10 .2, status=BUSY], Employee [id=null, name=张七, age=823, salary=10.3, status=FREE], Employee [id=null, name=张六, age=183121, salary=99.2, status= VOCATION], Employee [id=null, name=张三, age=18, salary=999.99, status=BUSY], Employee [id=null, name=张五, age=28213, salary=9199.99, status=F REE], Employee [id=null, name=张四, age=36, salary=9992341.99, status=FREE]]
