rxjava : 过滤操作符:filter(条件过滤)、 distinct(去重)、ofType(类型过滤)、buffer(缓存)

本文主要是介绍rxjava : 过滤操作符:filter(条件过滤)、 distinct(去重)、ofType(类型过滤)、buffer(缓存),希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!

filter :

根据过滤规则过滤数据

@Test
public void filter() {ArrayList<Student> students = new ArrayList<>();students.add(new Student("1", 1));students.add(new Student("2", 20));students.add(new Student("2", 21));students.add(new Student("2", 23));students.add(new Student("3", 3));students.add(new Student("4", 4));students.add(new Student("5", 50));students.add(new Student("6", 6));students.add(new Student("7", 7));Disposable disposable = Observable.fromIterable(students).filter(student -> student.getAge() > 21).subscribe(student ->System.out.println("student==========="+ student.toString()));
}
//student===========Student{name='2', age=23}
//student===========Student{name='5', age=50}

distinct : 去重

/*** 去重 : distinct*/
@Test
public void distinct1() {Disposable disposable = Observable.just("a", "d", "b", "c", "a", "e", "b", "c", "a", "b").distinct().subscribe(new Consumer<String>() {@Overridepublic void accept(String s) {System.out.println("s=============" + s);}});
}
//s=============a
//s=============d
//s=============b
//s=============c
//s=============e/*** 去重对象 : distinct*/
@Test
public void distinct2() {ArrayList<Student> students = new ArrayList<>();students.add(new Student("1", 1));students.add(new Student("2", 20));students.add(new Student("2", 21));students.add(new Student("2", 23));students.add(new Student("3", 3));students.add(new Student("4", 4));students.add(new Student("5", 50));students.add(new Student("6", 6));students.add(new Student("7", 7));Disposable disposable = Observable.fromIterable(students).distinct(new Function<Student, String>() {@Overridepublic String apply(Student student) throws Exception {return student.getName();//如果两个学生name一样就过滤(去重)//return student.getName() + student.getAge(); //如果多个条件同时,可以采取属性拼接的方式}}).subscribe(new Consumer<Student>() {@Overridepublic void accept(Student student) throws Exception {System.out.println("student==========="+ student.toString());}});
}
//student===========Student{name='1', age=1}
//student===========Student{name='2', age=20}
//student===========Student{name='3', age=3}
//student===========Student{name='4', age=4}
//student===========Student{name='5', age=50}
//student===========Student{name='6', age=6}
//student===========Student{name='7', age=7}
public 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;}@Overridepublic String toString() {return "Student{" +"name='" + name + '\'' +", age=" + age +'}';}
}

distinct : 去重二

/*** 去重对象 2个条件并再次组合成集合 : distinct*/public void distinct3() {ArrayList<Student> students = getStudents();Disposable disposable = Observable.fromIterable(students).distinct(new Function<Student, Integer>() {@Overridepublic Integer apply(Student student) throws Exception {//返回过滤条件,如果为默认值0,不过滤return student.getAge() != 0 ?student.getAge() :new Random().nextInt(Integer.MAX_VALUE);}}).distinct(new Function<Student, String>() {@Overridepublic String apply(Student student) throws Exception {//返回过滤条件,如果为空,不过滤return !TextUtils.isEmpty(student.getName()) ?student.getName() :UUID.randomUUID().toString();}}).toList()   //再合并各个数据.subscribe(new Consumer<List<Student>>() {@Overridepublic void accept(List<Student> students) throws Exception {if (students != null) {for (int i = 0; i < students.size(); i++) {System.out.println("students======"+ students.get(i).toString());}}}}, new Consumer<Throwable>() {@Overridepublic void accept(Throwable throwable) throws Exception {System.out.println("throwable======"+ throwable.getMessage());}});}//students======Student{name='1', age=11, school='11'}//students======Student{name='2', age=21, school='21'}//students======Student{name='3', age=31, school='31'}//students======Student{name='4', age=41, school='41'}//students======Student{name='5', age=51, school='51'}//students======Student{name='6', age=61, school='61'}//students======Student{name='7', age=71, school='71'}//students======Student{name='8', age=81, school='81'}//students======Student{name='9', age=91, school='91'}//students======Student{name='null', age=92, school='92'}//students======Student{name='null', age=93, school='93'}//students======Student{name='null', age=0, school='95'}//students======Student{name='null', age=0, school='96'}//students======Student{name='10', age=0, school='101'}private ArrayList<Student> getStudents() {ArrayList<Student> students = new ArrayList<>();students.add(new Student("1", 11, "11"));students.add(new Student("2", 21, "21"));students.add(new Student("2", 22, "22"));students.add(new Student("3", 22, "23"));students.add(new Student("3", 31, "31"));students.add(new Student("4", 41, "41"));students.add(new Student("4", 41, "42"));students.add(new Student("5", 51, "51"));students.add(new Student("6", 61, "61"));students.add(new Student("7", 71, "71"));students.add(new Student("8", 81, "81"));students.add(new Student("8", 81, "82"));students.add(new Student("8", 82, "83"));students.add(new Student("9", 91, "91"));students.add(new Student(null, 92, "92"));students.add(new Student(null, 93, "93"));students.add(new Student(null, 93, "94"));students.add(new Student(null, 0, "95"));students.add(new Student(null, 0, "96"));students.add(new Student("10", 0, "101"));return students;}
public class Student {private String name;private int age;private String school;public Student(String name, int age, String school) {this.name = name;this.age = age;this.school = school;}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;}public String getSchool() {return school;}public void setSchool(String school) {this.school = school;}@Overridepublic String toString() {return "Student{" +"name='" + name + '\'' +", age=" + age +", school='" + school + '\'' +'}';}
}

ofType : 类型过滤

@Test
public void ofType1() {Disposable disposable = Observable.just("first", 2d, 3L, "four", 5, false).ofType(Integer.class)//只需要Integer.subscribe(new Consumer<Integer>() {@Overridepublic void accept(Integer integer) {System.out.println("integer=============" + integer);}});
}
//integer=============5//类型过滤
@Test
public void ofType2() {Object[] data = {"first", "2", 3, "four", 5, 6, 7};Disposable disposable = Observable.fromArray(data).ofType(Integer.class).filter(new Predicate<Integer>() {@Overridepublic boolean test(Integer integer) throws Exception {return integer > 5;}}).subscribe(new Consumer<Integer>() {@Overridepublic void accept(Integer integer) throws Exception {System.out.println("integer=============" + integer);}});
}
//integer=============6
//integer=============7

buffer : 缓存

buffer:隔m(skip)个数取n(count)个数

“buffer”允许您收集值并以批量形式获取它们,而不是一次收集一个值。它们是缓冲值的几种不同方式。

@Test
public void buffer1() {Disposable disposable = Observable.range(1, 10).buffer(2)//每次take两个.subscribe(System.out::println);
}
//[1, 2]
//[3, 4]
//[5, 6]
//[7, 8]
//[9, 10]@Test
public void buffer2() {//skip分组[1,2,3][4,5,6][7,8,9][10],再take取值//当count < skip,元素被排除在外Disposable disposable = Observable.range(1, 10).buffer(2, 3)//每次skip三个,只take两个.subscribe(System.out::println);
}
//[1, 2]
//[4, 5]
//[7, 8]
//[10]@Test
public void buffer3() {//skip分组[1,2][3,4][5,6][7,8][9,10],再take取值//当count > skip,缓冲区重叠Disposable disposable = Observable.range(1, 10).buffer(3, 2).subscribe(System.out::println);}
//[1, 2, 3]
//[3, 4, 5]
//[5, 6, 7]
//[7, 8, 9]
//[9, 10]@Test
public void buffer4() {//skip分组[1,2][3,4][5,6][7,8][9,10],再take取值Disposable disposable = Observable.range(1, 10)//count : 每个缓冲区应发出的最大大小//skip : 开始新的缓冲区之前,应跳过源ObservableSource发出的多少项。// 请注意,当{@code skip}和{@code count}相等时,// 此操作与 {@link #buffer(int)}相同。.buffer(2, 2).subscribe(System.out::println);
}
//[1, 2]
//[3, 4]
//[5, 6]
//[7, 8]
//[9, 10]@Test
public void buffer5() {PublishSubject<String> subject = PublishSubject.create();Disposable disposable = subject.buffer(3)//获取三个为一组发送.subscribe(new Consumer<List<String>>() {@Overridepublic void accept(List<String> stringList) throws Exception {StringBuilder content = new StringBuilder();for (String s : stringList) {content.append(s).append(",");}System.out.println("content=======" + content);}});subject.onNext("1");subject.onNext("2");subject.onNext("3");subject.onNext("4");subject.onNext("5");subject.onNext("6");subject.onNext("7");subject.onNext("8");subject.onNext("9");subject.onNext("10");subject.onComplete();
}
//content=======1,2,3,
//content=======4,5,6,
//content=======7,8,9,
//content=======10,

这篇关于rxjava : 过滤操作符:filter(条件过滤)、 distinct(去重)、ofType(类型过滤)、buffer(缓存)的文章就介绍到这儿,希望我们推荐的文章对编程师们有所帮助!



http://www.chinasem.cn/article/526673

相关文章

Java实现字节字符转bcd编码

《Java实现字节字符转bcd编码》BCD是一种将十进制数字编码为二进制的表示方式,常用于数字显示和存储,本文将介绍如何在Java中实现字节字符转BCD码的过程,需要的小伙伴可以了解下... 目录前言BCD码是什么Java实现字节转bcd编码方法补充总结前言BCD码(Binary-Coded Decima

SpringBoot全局域名替换的实现

《SpringBoot全局域名替换的实现》本文主要介绍了SpringBoot全局域名替换的实现,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友们下面随着小编来一... 目录 项目结构⚙️ 配置文件application.yml️ 配置类AppProperties.Ja

Java使用Javassist动态生成HelloWorld类

《Java使用Javassist动态生成HelloWorld类》Javassist是一个非常强大的字节码操作和定义库,它允许开发者在运行时创建新的类或者修改现有的类,本文将简单介绍如何使用Javass... 目录1. Javassist简介2. 环境准备3. 动态生成HelloWorld类3.1 创建CtC

JavaScript中的高级调试方法全攻略指南

《JavaScript中的高级调试方法全攻略指南》什么是高级JavaScript调试技巧,它比console.log有何优势,如何使用断点调试定位问题,通过本文,我们将深入解答这些问题,带您从理论到实... 目录观点与案例结合观点1观点2观点3观点4观点5高级调试技巧详解实战案例断点调试:定位变量错误性能分

Java实现将HTML文件与字符串转换为图片

《Java实现将HTML文件与字符串转换为图片》在Java开发中,我们经常会遇到将HTML内容转换为图片的需求,本文小编就来和大家详细讲讲如何使用FreeSpire.DocforJava库来实现这一功... 目录前言核心实现:html 转图片完整代码场景 1:转换本地 HTML 文件为图片场景 2:转换 H

Java使用jar命令配置服务器端口的完整指南

《Java使用jar命令配置服务器端口的完整指南》本文将详细介绍如何使用java-jar命令启动应用,并重点讲解如何配置服务器端口,同时提供一个实用的Web工具来简化这一过程,希望对大家有所帮助... 目录1. Java Jar文件简介1.1 什么是Jar文件1.2 创建可执行Jar文件2. 使用java

SpringBoot实现不同接口指定上传文件大小的具体步骤

《SpringBoot实现不同接口指定上传文件大小的具体步骤》:本文主要介绍在SpringBoot中通过自定义注解、AOP拦截和配置文件实现不同接口上传文件大小限制的方法,强调需设置全局阈值远大于... 目录一  springboot实现不同接口指定文件大小1.1 思路说明1.2 工程启动说明二 具体实施2

Java实现在Word文档中添加文本水印和图片水印的操作指南

《Java实现在Word文档中添加文本水印和图片水印的操作指南》在当今数字时代,文档的自动化处理与安全防护变得尤为重要,无论是为了保护版权、推广品牌,还是为了在文档中加入特定的标识,为Word文档添加... 目录引言Spire.Doc for Java:高效Word文档处理的利器代码实战:使用Java为Wo

SpringBoot日志级别与日志分组详解

《SpringBoot日志级别与日志分组详解》文章介绍了日志级别(ALL至OFF)及其作用,说明SpringBoot默认日志级别为INFO,可通过application.properties调整全局或... 目录日志级别1、级别内容2、调整日志级别调整默认日志级别调整指定类的日志级别项目开发过程中,利用日志

Java中的抽象类与abstract 关键字使用详解

《Java中的抽象类与abstract关键字使用详解》:本文主要介绍Java中的抽象类与abstract关键字使用详解,本文通过实例代码给大家介绍的非常详细,感兴趣的朋友跟随小编一起看看吧... 目录一、抽象类的概念二、使用 abstract2.1 修饰类 => 抽象类2.2 修饰方法 => 抽象方法,没有