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📝 update lambda lesson1
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‎README.md‎

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@@ -22,7 +22,7 @@ java 8 改变了我们思考和编码的方式，在这里你可以学习到 Jav
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|:-----:|:--------|:-------|:-------|
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|第 1 课 | 课程介绍 | [哔哩哔哩](https://www.bilibili.com/video/av19287893/index_2.html#page=1) ¦ [Youtube](https://youtu.be/A733pQxiEDk) | 无 |
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|第 2 课 | Java 8 的发展 | [哔哩哔哩](https://www.bilibili.com/video/av19287893/index_2.html#page=2) ¦ [Youtube](https://youtu.be/fHhgm1AZzhs) | [java8-growing](https://github.com/biezhi/learn-java8/tree/master/java8-growing/src/main/java/io/github/biezhi/java8/growing) |
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|第 3 课 | 理解 lambda | 哔哩哔哩 ¦ Youtube | |
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|第 3 课 | 理解 lambda | [哔哩哔哩](https://www.bilibili.com/video/av19287893/index_2.html#page=3) ¦ [Youtube](https://youtu.be/Epm5C8fyvsE) | [java8-growing](https://github.com/biezhi/learn-java8/tree/master/java8-lambda/src/main/java/io/github/biezhi/java8/lambda/lesson1) |
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|第 4 课 | 初尝 lambda | 哔哩哔哩 ¦ Youtube | |
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|第 5 课 | lambda 进阶 | 哔哩哔哩 ¦ Youtube | |
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|第 6 课 | 默认方法的妙用 | 哔哩哔哩 ¦ Youtube | |

‎java8-lambda/src/main/java/io/github/biezhi/java8/lambda/lesson1/FilterProjects.java‎

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package io.github.biezhi.java8.lambda.lesson1;
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import io.github.biezhi.java8.lambda.lesson1.predicate.ProjectLanguagePredicate;
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import io.github.biezhi.java8.lambda.lesson1.predicate.ProjectStarPredicate;
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import javax.swing.*;
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import java.awt.event.ActionEvent;
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import java.awt.event.ActionListener;
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import java.util.ArrayList;
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import java.util.Comparator;
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import java.util.List;
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import java.util.function.Predicate;
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/**
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* 过滤 Project
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*
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* @author biezhi
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* @date 2018/2/9
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*/
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public class FilterProjects {
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/**
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* 过滤 Java 项目
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*
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* @param projects
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* @return
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*/
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public static List<Project> filterJavaProjects(List<Project> projects) {
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List<Project> result = new ArrayList<>();
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for (Project project : projects) {
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if ("java".equals(project.getLanguage())) {
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result.add(project);
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}
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}
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return result;
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}
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/**
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* 按语言过滤
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*
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* @param projects
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* @param language
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* @return
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*/
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public static List<Project> filterLanguageProjects(List<Project> projects, String language) {
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List<Project> result = new ArrayList<>();
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for (Project project : projects) {
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if (language.equals(project.getLanguage())) {
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result.add(project);
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}
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}
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return result;
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}
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/**
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* 按语言和 star 数过滤
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*
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* @param projects
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* @param language
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* @param stars
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* @return
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*/
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public static List<Project> filterLanguageAndStarProjects(List<Project> projects, String language, int stars) {
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List<Project> result = new ArrayList<>();
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for (Project project : projects) {
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if (language.equals(project.getLanguage()) && project.getStars() > stars) {
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result.add(project);
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}
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}
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return result;
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}
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/**
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* 按照谓词条件过滤
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*
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* @param projects
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* @param projectPredicate
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* @return
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*/
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public static List<Project> filterProjects(List<Project> projects, ProjectPredicate projectPredicate) {
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List<Project> result = new ArrayList<>();
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for (Project project : projects) {
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if (projectPredicate.test(project)) {
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result.add(project);
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}
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}
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return result;
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}
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public static <T> List<T> filter(List<T> list, Predicate<T> predicate){
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List<T> result = new ArrayList<>();
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for (T t : list) {
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if(predicate.test(t)){
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result.add(t);
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}
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}
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return result;
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}
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public static void main(String[] args) {
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List<Project> data = new ArrayList<>();
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data.add(Project.builder().name("Blade").language("java").author("biezhi")
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.stars(3500).description("Lightning fast and elegant mvc framework for Java8").build());
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data.add(Project.builder().name("Tale").language("java").author("biezhi")
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.stars(2600).description("Best beautiful java blog, worth a try").build());
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data.add(Project.builder().name("Vue.js").language("js").author("yyx990803")
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.stars(83000).description("A progressive, incrementally-adoptable JavaScript framework for building UI on the web.").build());
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data.add(Project.builder().name("Flask").language("python").author("pallets")
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.stars(10500).description("The Python micro framework for building web applications").build());
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data.add(Project.builder().name("Elves").language("java").author("biezhi")
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.stars(200).description("Spider").build());
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List<Project> projects = filterJavaProjects(data);
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projects = filterLanguageProjects(data, "python");
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projects = filterLanguageAndStarProjects(data, "js", 1000);
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projects = filterProjects(data, new ProjectLanguagePredicate("python"));
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projects = filterProjects(data, new ProjectStarPredicate(1000));
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System.out.println(projects.size());
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// JButton jButton = null;
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// jButton.addActionListener(e -> System.out.println("按钮被按下了"));
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// 1. 值参数化：啰嗦、死板
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// 2. 行为参数化：简洁、灵活
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List<Project> filter = filter(data, project -> project.getStars() > 1000);
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data.sort(Comparator.comparing(Project::getStars));
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System.out.println(data);
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Runnable task = () -> System.out.println("Hello World");
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Thread t = new Thread(task);
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t.start();
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}
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}

‎java8-lambda/src/main/java/io/github/biezhi/java8/lambda/lesson1/Project.java‎

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package io.github.biezhi.java8.lambda.lesson1;
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import lombok.Builder;
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import lombok.Data;
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/**
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* 项目
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*
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* @author biezhi
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* @date 2018/2/9
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*/
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@Data
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@Builder
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public class Project {
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/**
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* 项目名称
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*/
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private String name;
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/**
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* 编程语言
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*/
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private String language;
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/**
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* star 数
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*/
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private Integer stars;
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/**
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* 描述
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*/
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private String description;
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/**
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* 作者
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*/
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private String author;
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}

‎java8-lambda/src/main/java/io/github/biezhi/java8/lambda/lesson1/ProjectPredicate.java‎

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package io.github.biezhi.java8.lambda.lesson1;
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/**
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* 项目过滤接口
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*
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* @author biezhi
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* @date 2018/2/9
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*/
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public interface ProjectPredicate {
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boolean test(Project project);
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}

‎java8-lambda/src/main/java/io/github/biezhi/java8/lambda/lesson1/predicate/ProjectLanguagePredicate.java‎

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package io.github.biezhi.java8.lambda.lesson1.predicate;
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import io.github.biezhi.java8.lambda.lesson1.Project;
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import io.github.biezhi.java8.lambda.lesson1.ProjectPredicate;
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/**
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* 按编程语言过滤
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*
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* @author biezhi
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* @date 2018/2/9
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*/
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public class ProjectLanguagePredicate implements ProjectPredicate {
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private String language;
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public ProjectLanguagePredicate(String language) {
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this.language = language;
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}
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@Override
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public boolean test(Project project) {
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return language.equals(project.getLanguage());
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}
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}

‎java8-lambda/src/main/java/io/github/biezhi/java8/lambda/lesson1/predicate/ProjectStarPredicate.java‎

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package io.github.biezhi.java8.lambda.lesson1.predicate;
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import io.github.biezhi.java8.lambda.lesson1.Project;
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import io.github.biezhi.java8.lambda.lesson1.ProjectPredicate;
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/**
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* 按 star 数过滤
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*
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* @author biezhi
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* @date 2018/2/9
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*/
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public class ProjectStarPredicate implements ProjectPredicate {
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private Integer stars;
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public ProjectStarPredicate(Integer stars) {
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this.stars = stars;
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}
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@Override
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public boolean test(Project project) {
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return project.getStars() > stars;
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}
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}

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