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1. lambda表达式 案例
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1 parent 87995be commit c3b9dc8

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‎README.md‎

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@@ -33,6 +33,7 @@ Java核心技术学习代码兼测试案例<br>
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├── org.javacore.thread // Java 线程
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=================实战JAVA 8=================
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├── org.javacore.lambda // lambda表达式
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├── org.javacore.stream // Stream API 集合的流式操作
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│
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拼命更新！顶！d=====(￣▽￣*)b
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src/org/javacore/lambda/LambdaTest01.java renamed to src/org/javacore/lambda/LambdaListCompare.java

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package org.javacore.lambda;
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/*
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* Copyright [2015] [Jeff Lee]
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import java.util.ArrayList;
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import java.util.List;
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/**
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* List 比较器
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* <p/>
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*
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* Created by bysocket on 16/7/12.
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*/
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public class LambdaTest01 {
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public class LambdaListCompare {
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public static void main(String[] args) {
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List<Integer> list = new ArrayList<>();
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list.add(4);

‎src/org/javacore/lambda/LambdaOperators.java‎

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package org.javacore.lambda;
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/*
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* Copyright [2015] [Jeff Lee]
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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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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/**
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* Lambda 操作符
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*
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* Created by bysocket on 16/7/13.
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*/
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public class LambdaOperators {
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public static void main(String[] args) {
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List<String> list = new ArrayList<>();
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list.add("aaa");
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list.add("cccc");
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list.add("b");
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list.add("eeeee");
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/**
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* :: 操作符格式 => 三种情况
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* 对象::实例方法
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* 类::静态方法
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* 类::实例方法 对于前两种情况，方法引用就是对参数执行该方法。比如下面两种方法
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*/
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// 按字符串大小排序忽略大小写
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list.sort(String::compareToIgnoreCase);
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// 打印 list 元素
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list.forEach(System.out::println);
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System.out.println("======按字符大小排序======");
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list.sort(Comparator.comparing(String::length));
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list.forEach(System.out::println);
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}
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}

‎src/org/javacore/lambda/LambdaRunnable.java‎

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package org.javacore.lambda;
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/*
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* Copyright [2015] [Jeff Lee]
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/**
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* Lambda - 启动线程
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*
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* Created by bysocket on 16/7/13.
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*/
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public class LambdaRunnable {
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static int b = 10;
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public static void main(String[] args) {
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// 启动线程
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// Thread thread = new Thread(new Runnable() {
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// @Override
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// public void run() {
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// b++;
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// System.out.println(b);
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// }
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// });
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// Lambda - 启动线程
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Thread thread = new Thread(() -> {
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b++;
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System.out.println(b);

‎src/org/javacore/lambda/LambdaTest02.java‎

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‎src/org/javacore/scheduler/TimerTest.java‎

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package org.javacore.scheduler; /*
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package org.javacore.scheduler;
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/*
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* Copyright [2015] [Jeff Lee]
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*
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* Licensed under the Apache License, Version 2.0 (the "License");

‎src/org/javacore/stream/CollectStreamTest.java‎

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package org.javacore.stream;
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/*
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* Copyright [2015] [Jeff Lee]
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import java.util.Arrays;
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import java.util.List;
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import java.util.stream.Collectors;
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/**
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*
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* Created by bysocket on 16/7/14.
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*/
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public class CollectStreamTest {
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public static void main(String[] args) {
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List<Integer> list = Arrays.asList(1,2,3,4);
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Double result = list.stream().collect(Collectors.averagingDouble(d->d*2));
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System.out.println(result);
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}
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}

‎src/org/javacore/stream/CollectionStreamTest.java‎

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package org.javacore.stream;
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/*
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* Copyright [2015] [Jeff Lee]
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import java.util.ArrayList;
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import java.util.List;
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import java.util.stream.Collectors;
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import java.util.stream.Stream;
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/**
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* Stream API 集合的流式操作
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*
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* Created by bysocket on 16/7/13.
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*/
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public class CollectionStreamTest {
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public static void main(String[] args) {
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List<String> list = new ArrayList<>();
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list.add("aa");
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list.add("cccc");
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list.add("bbb");
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/**
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* Stream的使用:
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* 创建/获取流 -> 中间操作（过滤、转换等） -> 终止操作（ 聚合、收集结果）
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*/
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list.stream().forEach(System.out::println);
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System.out.println();
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/**
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* 过滤
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* collect语法 {@link StreamCollectTest}
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*/
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List list0 = list.stream().filter(str -> str.startsWith("cc")).collect(Collectors.toList());
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List list1 = list.stream().filter(str -> str.startsWith("aa")).collect(Collectors.toList());
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list0.stream().forEach(System.out::println);
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list1.stream().forEach(System.out::println);
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System.out.println();
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/**
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* 转换
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*/
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List list2 = list.stream().map(str -> str.replace("c","*")).collect(Collectors.toList());
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list2.stream().forEach(System.out::println);
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System.out.println();
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/**
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* 提取
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* 从skip开始至limit位置为止
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*/
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List list3 = list.stream().skip(0).limit(1).collect(Collectors.toList());
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list3.stream().forEach(System.out::println);
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System.out.println();
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/**
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* 组合
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*/
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List list4 = Stream.concat(list.stream(),list.stream()).collect(Collectors.toList());
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list4.stream().forEach(System.out::println);
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System.out.println();
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}
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}

‎src/org/javacore/stream/CollectionStreamTest01.java‎

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package org.javacore.stream;
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/*
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* Copyright [2015] [Jeff Lee]
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import java.util.Arrays;
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import java.util.List;
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/**
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* Stream API 集合的流式操作
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* <p/>
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* Created by bysocket on 16/7/13.
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*/
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public class CollectionStreamTest01 {
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public static void main(String[] args) {
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List<String> strList = Arrays.asList("a1", "a2", "c3", "c6", "c4");
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strList
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.stream()
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.filter(str -> str.startsWith("c"))
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.map(String::toUpperCase)
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.sorted()
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.forEach(System.out::println);
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}
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}

‎src/org/javacore/stream/ConcatStreamTest.java‎

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package org.javacore.stream;
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/*
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* Copyright [2015] [Jeff Lee]
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import java.util.Arrays;
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import java.util.List;
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import java.util.stream.Collectors;
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import java.util.stream.Stream;
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/**
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* 组合 - 流
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*
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* Created by bysocket on 16/7/14.
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*/
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public class ConcatStreamTest {
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public static void main(String[] args) {
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List<String> list1 = Arrays.asList("a","b","c");
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List<String> list2 = Arrays.asList("d","e","f");
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// 组合list1和list2的流
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List result = Stream.concat(list1.stream(),list2.stream()).collect(Collectors.toList());
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result.stream().forEach(System.out::println);
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}
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}

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