add collections 🆕 📖

Author: haiji.yang

.gitignore

@@ -3,7 +3,7 @@ target/
 !.mvn/wrapper/maven-wrapper.jar
 !**/src/main/**/target/
 !**/src/test/**/target/
-
+out
 ### STS ###
 .apt_generated
 .classpath

README.md

@@ -28,7 +28,8 @@
         - [3.1.JDK 8 HashMap鬼斧神工的优化](https://blog.csdn.net/weixin_38937840/article/details/106805496)
         - [3.2.JDK8 Map merge 一些骚操作](note/java/collection/map/map_merge.md)
         - [3.3.JDK8 一行代码搞定集合去重，差集，并集，交集，是否相等](https://blog.csdn.net/weixin_38937840/article/details/107338265)
-        - [3.4.JDK14 ArrayList 分析](note/java/collection/list/ArrayList.md)    
+        - [3.4.JDK14 ArrayList 分析](note/java/collection/list/ArrayList.md)  
+        - [3.5.Collections 工具类学习](note/java/collection/collections/collections.md)  
     - [4.Java NIO](note/java/README.md)    
         - [4.1.Java NIO 教程](note/java/nio/book/JavaNIO教程.md)    
         - [4.2.Java NIO 概览](note/java/nio/book/JavaNIO概览.md)    

leetcode/src/main/java/com/java/leetcode/algorithm/ThreadTest.java

@@ -0,0 +1,38 @@
+package com.java.leetcode.algorithm;
+
+/**
+ * <p>
+ *
+ * </p>
+ *
+ * @author Dylan
+ * @version 1.0.0
+ * @since 2020-11-06 3:52 PM
+ */
+public class ThreadTest {
+    public static void main(String[] args) {
+        InfoServer infoServer = new InfoServer("测试");
+
+        Thread thread = new Thread(infoServer);
+        System.out.println(thread.isDaemon());
+        thread.start();
+    }
+}
+
+class InfoServer implements Runnable{
+
+    private final String msg;
+
+    public InfoServer(String msg) {
+        this.msg = msg;
+    }
+
+    public void printInfo(String msg){
+        System.out.println("线程设计:"+msg);
+    }
+
+    @Override
+    public void run() {
+        printInfo(msg);
+    }
+}

note/java/README.md

@@ -21,6 +21,7 @@
     - [3.2.JDK8 Map merge 一些骚操作](collection/map/map_merge.md)
     - [3.3.JDK8 一行代码搞定集合去重，差集，并集，交集，是否相等](https://blog.csdn.net/weixin_38937840/article/details/107338265)
     - [3.4.JDK14 ArrayList 分析](collection/list/ArrayList.md)
+    - [3.5.Collections 工具类学习](collection/collections/collections.md)
 - [4.Java NIO](nio/README.md)    
     - [4.1.Java NIO 教程](nio/book/JavaNIO教程.md)    
     - [4.2.Java NIO 概览](nio/book/JavaNIO概览.md)    

note/java/collection/README.md

@@ -2,8 +2,9 @@
 #  Java collection
 
 - [1.JDK 8 HashMap鬼斧神工的优化](https://blog.csdn.net/weixin_38937840/article/details/106805496)
-- [2.JDK8 Map merge 一些骚操作](collection/map/map_merge.md)
+- [2.JDK8 Map merge 一些骚操作](map/map_merge.md)
 - [3.JDK8 一行代码搞定集合去重，差集，并集，交集，是否相等](https://blog.csdn.net/weixin_38937840/article/details/107338265)
-- [4.JDK14 ArrayList 分析](collection/list/ArrayList.md)
+- [4.JDK14 ArrayList 分析](list/ArrayList.md)
+- [5.Collections 工具类学习](collections/collections.md)
 
 

note/java/collection/collections/collections.md

@@ -75,7 +75,7 @@ Java堆区用于存储Java对象实例，那么堆的大小在JVM启动时就已
 
 一旦堆区中的内存大小超过“-xmx"所指定的最大内存时，将会抛出outofMemoryError异常。
 
-通常会将-Xms和-Xmx两个参数配置相同的值，其目的是**为了能够在ava垃圾回收机制清理完堆区后不需要重新分隔计算堆区的大小，从而提高性能**。
+通常会将-Xms和-Xmx两个参数配置相同的值，其目的是**为了能够在java垃圾回收机制清理完堆区后不需要重新分隔计算堆区的大小，从而提高性能**。
 
 默认情况下
 

note/java/collection/collections/img/syncList.png

@@ -0,0 +1,50 @@
+package com.javayh.advanced.java.collection.collections;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * <p>
+ * Collections code
+ * </p>
+ *
+ * @author Dylan
+ * @version 1.0.0
+ * @since 2020-11-18 3:46 PM
+ */
+public class CollectionsTest {
+    public static void main(String[] args) {
+        List<String> listOne = new ArrayList<>();
+        String[] strings = new String[]{"List","Set","Map"};
+        Collections.addAll(listOne,"Yang","Hai","ji");
+        Collections.addAll(listOne,strings);
+        System.out.println(listOne);
+
+        List<String> listTwo = new ArrayList<>();
+        for (int i = 0; i < 1000; i++) {
+            listTwo.add("Yang"+i);
+        }
+        int yang999 = Collections.binarySearch(listTwo, "Yang999");
+        System.out.println(yang999);
+
+        List<String> linkedList = new LinkedList<>();
+        for (int i = 0; i < 5050; i++) {
+            linkedList.add("Hai"+i);
+        }
+        int hai = Collections.binarySearch(linkedList, "Hai999");
+        System.out.println(hai);
+
+        List<String> syncList = Collections.synchronizedList(new ArrayList<>());
+
+
+        List<String> disjointList1 = new ArrayList<>();
+        List<String> disjointList2 = new ArrayList<>();
+        boolean disjoint = Collections.disjoint(disjointList1, disjointList2);
+
+        System.out.println(Collections.max(listOne));
+
+    }
+}
+

note/java/jvm/内存与垃圾回收篇/8_堆/README.md

@@ -0,0 +1,34 @@
+package com.javayh.advanced.java;
+
+/**
+ * <p>
+ *
+ * </p>
+ *
+ * @author hai ji
+ * @version 1.0.0
+ * @since 2020-10-15
+ */
+public class test {
+    public static void main(String[] args) {
+        // 获取系统类加载器
+        ClassLoader systemClassLoader = ClassLoader.getSystemClassLoader();
+        System.out.println(systemClassLoader);
+
+        // 获取其上层的：扩展类加载器
+        ClassLoader extClassLoader = systemClassLoader.getParent();
+        System.out.println(extClassLoader);
+
+        // 试图获取 根加载器
+        ClassLoader bootstrapClassLoader = extClassLoader.getParent();
+        System.out.println(bootstrapClassLoader);
+
+        // 获取自定义加载器
+        ClassLoader classLoader = test.class.getClassLoader();
+        System.out.println(classLoader);
+
+        // 获取String类型的加载器
+        ClassLoader classLoader1 = String.class.getClassLoader();
+        System.out.println(classLoader1);
+    }
+}