Java8新特性之filter过滤器 - 好文

【过滤器案例】：使用Stream对象的filter()方法过滤出集合中Person对象name属性含有”菲”字的对象

创建Person类：
public class Person { public static enum Sex{ MALE,FEMALE; } private String
name;private Sex gender; private int age; private double height; public Person
() { }public Person(String name, Sex gender, int age, double height) { super();
this.name = name; this.gender = gender; this.age = age; this.height = height; }
public String getName() { return name; } public void setName(String name) { this
.name = name; }public Sex getGender() { return gender; } public void setGender
(Sex gender) {this.gender = gender; } public int getAge() { return age; } public
void setAge(int age) { this.age = age; } public double getHeight() { return
height; }public void setHeight(double height) { this.height = height; }
@Override public String toString() { return "Person [name=" + name + ", gender="
+ gender +", age=" + age + ", height=" + height + "]"; } }
创建测试类，在测试类中创建一个初始化集合的静态方法：
public class Test04_collection_filter { //初始化集合的静态方法 public static List<Person>
createPerson(){ List<Person> people = new ArrayList<Person>(); Person person =
new Person("张飞",Person.Sex.MALE,33,1.99); people.add(person); person = new
Person("王菲",Person.Sex.FEMALE,33,1.65); people.add(person); person = new Person(
"刘亦菲",Person.Sex.FEMALE,33,1.68); people.add(person); person = new Person("李四"
,Person.Sex.MALE,33,1.76); people.add(person); person = new Person("小马"
,Person.Sex.MALE,33,1.71); people.add(person); person = new Person("郭靖"
,Person.Sex.MALE,33,1.88); people.add(person); return people; } }
在该测试类中，添加main方法，用来测试filter过滤器：
public static void main(String[] args) { List<Person> people = createPerson();
//调用初始化集合的静态方法，初始化一个集合 Stream<Person> stream = people.stream(); stream.filter(p
-> p.getName().indexOf("菲")>-1)//过滤器中传入lambda表达式，表达式代码块中书写判断条件，返回一个布尔值
.forEach(p -> { System.out.println(p); });//紧接着调用forEach方法，遍历集合，打印集合中每个对象 }
运行main方法，控制台打印结果如下：
Person [name=王菲, gender=FEMALE, age=33, height=1.65] Person [name=刘亦菲,
gender=FEMALE, age=33, height=1.68]
本文代码资源地址：

https://github.com/gitHjx/java8.git <https://github.com/gitHjx/java8.git>

热门工具换一换