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摘要： package com.kaibing.thread; import java.util.concurrent.locks.Condition; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock; public class ABCAlternate { pu... 阅读全文

摘要： package com.kaibing.design; import java.util.concurrent.locks.Condition; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock; public class ProductorAndCustomerLo... 阅读全文

摘要： package com.kaibing.design; public class ProductorAndCustomer { public static void main(String[] args) { Clerk clerk = new Clerk(); Productor productor = new Productor(clerk);... 阅读全文

摘要： 查询优化： 定位问题： 1.记录慢查询 show profile set profiling = 1 开启 show profiles show profile for query 表ID show status ：计数器 show processlist ：记录线程 explain/desc ：分 阅读全文

摘要： 安装之前先检查一下系统有没有自带open-jdk 命令： rpm -qa |grep java rpm -qa |grep jdk rpm -qa |grep gcj 如果没有输入信息表示没有安装。 如果安装可以使用rpm -qa | grep java | xargs rpm -e --nodep 阅读全文

摘要： package com.kaibing.sortandfind; import org.junit.jupiter.api.Test; public class Find { public int[] arr = {1, 2, 3, 4, 5}; @Test public void binaryFind() { System.out.print... 阅读全文

摘要： package com.kaibing.sort; import org.junit.jupiter.api.Test; public class UpSort { public int[] arr = {1, 3, 2, 7, 5}; /** * 冒泡排序：思想每次把目标（最大或最小）移到末尾 * 时间：平均=O(n^2) | 最坏=O(n^2) ... 阅读全文

摘要： package com.kaibing.thread; /** * 线程的通信 * * wati() * notify()：随机唤醒一个 * notifyAll()：全部唤醒 */ class PrintNum implements Runnable { int num = 1; @Override public void run() { ... 阅读全文

摘要： public class DeadLock { static StringBuffer sb1 = new StringBuffer(); static StringBuffer sb2 = new StringBuffer(); public static void main(String[] args) { new Thread(()->{ ... 阅读全文

摘要： Write a SQL query to rank scores. If there is a tie between two scores, both should have the same ranking. Note that after a tie, the next ranking num 阅读全文