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转发：Android Bitmap压缩图像的正确方法(compress的误区)

**摘要：** Bitmap.compress方法确实可以压缩图片，但压缩的是存储大小，即你放到disk上的大小我尝试过把品质设置为10，decode出来的Bitmap大小没变，但显示照片的质量非常差 BitmapFactory.decodeByteArray方法对压缩后的byte[]解码后，得到的Bitmap大小依然和未压缩过一样如果你想要显示的Bitmap占用的内存少一点，还是需要去设置加载的像素长度和宽度（变成缩略图）原文地址：https://blog.csdn.net/T3/article/details/79665077

Linux下使用jps命令报错

# 问题：Linux下使用jps命令报错java.lang.Error: Properties init: Could not determine current working directory. ![QQ截图20210814141543.png][1] 解决方案 ![QQ截图20210814141703.png][2] cd .. 发现是因为刚才在xftp中删除了此目录导致的![QQ截图20210814141831.png][3] cd / cd到根目录，再尝试使用jps，发现问题已解决 [1]: https://www.caoxuan.top/usr/uploads/2021/08/1556106767.png [2]: https://www.caoxuan.top/usr/uploads/2021/08/3988254530.png [3]: https://www.caoxuan.top/usr/uploads/2021/08/2498345376.png

好久没写了，随便水一贴吧

公元二〇二一年七月二十日星期二六月十一辛丑年牛乙未月己巳日 2021/7/20

关于在Nginx中配置顶级域名与www域名之间跳转以及https和如何搭配CDN的综合解决方案

# 关于在Nginx中配置顶级域名与www域名之间跳转以及https和如何搭配CDN的综合解决方案方案一方案二（不推荐）方案三使用场景一般情况顶级域名存在邮件服务顶级域名存在邮件服务相对复杂度低中高终点 https://www.example.com https://www.example.com https://www.example.com 隐藏源站IP 是是是相对可用性高低高缺点无法在顶级域名存在邮件服务的情况下使用无法直接访问https://example.com 成本略高，配置麻烦特殊要求无要求DNS服务商支持显性URL转发需要一台代理服务器方案一源站配置（以Nginx为例）关于www和naked域名的重新向以及https的解决方案（以Nginx为例） - 西叉的代码屋 (caoxuan.top) CDN配置（以腾讯云为例）基础配置加速域名：www.example.com 源站类型：自有源回源协议：协议跟随源站地址：1.1.1.1（源站IP）回源HOST：www.example.com HTTPS配置强制跳转跳转配置：开跳转类型：http->https 跳转方式：301跳转携带头部：否 DNS配置（以阿里云为例）记录类型主机记录解析线路记录值 TTL CNAME www 默认 www.example.com.cdn.dnsv1.com（示例；实际以CDN控制台的为准） 10分钟 CNAME @ 默认 www.example.com 10分钟路径表起点过程浏览器请求次数 http://example.com 或 example.com 起点 -> CDN（301 https://example.com） https://example.com -> CDN -> 源站（301 https://www.example.com） https://www.example.com -> CDN -> 源站资源 3 http://www.example.com 或 www.example.com 起点 -> CDN（301 https://www.example.com） https://www.example.com -> CDN -> 源站资源 2 https://example.com 起点 -> CDN -> 源站（301 https://www.example.com） https://www.example.com -> CDN -> 源站资源 2 https://www.example.com 起点 -> CDN -> 源站资源 1 应急解决方案（保证可用性；前提：Nginx配置与本方案的源站配置相同） SSL出现问题步骤一：修改CDN的HTTPS配置关闭强制跳转 ...

关于www和naked域名的重新向以及https的解决方案（以Nginx为例）

以下是nginx的相关配置 #server1 http://example.com server { listen 80; server_name example.com; return 301 http://www.example.com$request_uri; } #server2 http://www.example.com server { listen 80; server_name www.example.com; return 301 https://$server_name$request_uri; } #server3 https://example.com server { listen 443 ssl http2; server_name example.com; ssl_certificate 0000000_example.com.pem; ssl_certificate_key 0000000_example.com.key; ssl_session_cache shared:SSL:10m; ssl_session_timeout 10m; ssl_protocols TLSv1.2 TLSv1.3; return 301 https://www.example.com$request_uri; } #server4 https://www.example.com server { listen 443 ssl ; server_name www.example.com; ssl_certificate 0000000_example.com.pem; ssl_certificate_key 0000000_example.com.key; ssl_session_cache shared:SSL:10m; ssl_session_timeout 10m; ssl_protocols TLSv1.2 TLSv1.3; location / { root /usr/share/nginx/html; index index.html index.htm; } } FAQs Q：为什么要重定向多次？而不直接重定向到 https://www.example.com ？ A：为了降低出错后的维护成本，当ssl出现问题时，只需修改一个server（server2）即可以http的方式访问，从而恢复正常工作。 Q：这样做对SEO有影响吗？ A：鄙人才疏学浅，请自行查阅资料了解。目前看来，使用Google可以搜索到本站的内容，但是某度却不行。

fastjson反序列化后缺失属性值

**原因分析**：fastjson在反序列化时用的默认使用无参构造方法和getter与setter来构造对象，如果缺少无参构造方法，则会使用当前存在的构造方法（这个构造方法的参数可能不齐全）来构造对象。解决方案：如果使用了Lombok，就在相应的实体类上添加注解*@NoArgsConstructor*；否则就手动重写无参构造方法。

RecyclerView只显示一条数据

![QQ截图20210415162531.png][1] 检查对应的item，将android:layout_height=“match_parent"改为android:layout_height=“wrap_content”。

简单实现负载均衡

```java package algorithm.loadbalance; import com.alibaba.fastjson.JSON; import java.util.*; /** @author Cao Xuan @date 2021/3/21 20:04 @update 2021/5/5 */ public class LoadBalanceDemo { private final List serverList = new ArrayList<>(); /** client -> server */ private final Map<Client, Server> clientServerMap = new HashMap<>(); /** <—head—tail—> <—light—weight—> <—former—latter–> */ @Deprecated private void sort() { for (int i = serverList.size() - 1; i > 0; i–) { for (int j = i - 1; j > -1; j–) { Server latter = new Server(serverList.get(i)); Server former = new Server(serverList.get(j)); if (latter.getCurrentLoad().size() > former.getCurrentLoad().size()) { serverList.set(i, former); serverList.set(j, latter); } } } System.out.println(“sorting…”); } /** <—head—tail—> <—light—weight—> <—former—latter–> */ private void leafShift() { int size = serverList.size(); for (int i = size - 2; i >= 0; i–) { Server latter = new Server(serverList.get(size - 1)); Server former = new Server(serverList.get(i)); if (latter.getCurrentLoad().size() > former.getCurrentLoad().size()) { serverList.set(size - 1, former); serverList.set(i, latter); System.out.println(“leaf shift”); } } } private void rightShift(int index) { int size = serverList.size(); for (int i = index + 1; i < size; i++) { Server former = new Server(serverList.get(index)); Server latter = new Server(serverList.get(i)); if (former.getCurrentLoad().size() < latter.getCurrentLoad().size()) { serverList.set(i, former); serverList.set(index, latter); System.out.println(“right shift”); } } } public Server addClient(Client client) { if (serverList.size() > 0) { Server server = new Server(serverList.get(serverList.size() - 1)); String serverName = server.getName(); serverList.get(serverList.size() - 1).updateCurrentLoad(client); System.out.println(“Hi,[” + client.getUsername() + “]. Assign [” + serverName + “] to you”); leafShift(); show(); return server; } else { System.err.println(“no server”); return null; } } public void removeClient(String clientName) { Server server = clientServerMap.get(new Client(clientName)); int index = serverList.indexOf(server); if (-1 != index) { server.currentLoad.remove(new Client(clientName)); rightShift(index); System.out.println(“remove a client [” + clientName + “]”); } else { System.err.println(“index = -1”); } show(); } public void addServer(String name) { Server server = new Server(name, new HashSet<>()); if (serverList.contains(server)) { System.err.println(“The server [” + name + “] already exists”); show(); return; } serverList.add(server); System.out.println(“add a server [” + name + “]”); show(); } public void removeServer(String serverName) { serverList.remove(new Server(serverName)); System.out.println(“add a server [” + serverName + “]”); show(); } private static class Client { private String username; public Client(String username) { this.username = username; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } @Override public boolean equals(Object obj) { if (!(obj instanceof Client)) { return false; } Client client = (Client) obj; return this.getUsername().equals(client.getUsername()); } @Override public int hashCode() { return Objects.hash(username); } @Override public String toString() { return JSON.toJSONString(this); } } private static class Server { private String name; private Set<Client> currentLoad; public Server(String name) { this.name = name; } public Server(Server server) { this.name = server.name; this.currentLoad = server.currentLoad; } public Server(String name, Set<Client> currentLoad) { this.name = name; this.currentLoad = currentLoad; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Set<Client> getCurrentLoad() { return currentLoad; } public void setCurrentLoad(Set<Client> currentLoad) { this.currentLoad = currentLoad; } public void updateCurrentLoad(Client client) { this.currentLoad.add(client); } @Override public boolean equals(Object obj) { if (!(obj instanceof Server)) { return false; } Server server = (Server) obj; return this.getName().equals(server.getName()); } @Override public String toString() { return JSON.toJSONString(this); } } public static void main(String[] args) { LoadBalanceDemo loadBalanceDemo = new LoadBalanceDemo(); System.out.println("---------------USAGE--------------"); System.out.println("Add a server: [s+${serverName}]"); System.out.println("Add a client: [c+${clientName}]"); System.out.println("Remove a server: [s-${serverName}]"); System.out.println("Remove a client: [c-${clientName}]"); System.out.println("Show Current Load: [show]"); System.out.println("---------------USAGE--------------"); while (true) { System.out.println("ready"); System.out.println(); Scanner scanner = new Scanner(System.in); String s = scanner.next(); if ("show".equals(s)) { loadBalanceDemo.show(); } else if (s.startsWith("c+")) { String clientName = s.substring(2); Client client = new Client(clientName); Server server = loadBalanceDemo.addClient(client); loadBalanceDemo.clientServerMap.put(client, server); } else if (s.startsWith("s+")) { String serverName = s.substring(2); loadBalanceDemo.addServer(serverName); } else if (s.startsWith("c-")) { String clientName = s.substring(2); loadBalanceDemo.removeClient(clientName); } else if (s.startsWith("s-")) { String serverName = s.substring(2); loadBalanceDemo.removeServer(serverName); } else { System.out.println("?"); } System.out.println("----------------------------------"); } } private void show() { System.out.println(“current load " + serverList); } } ...

群晖 GitServer用户为空的解决办法

参考https://chaolucky.com/blog/12/03-927.html sudo cp /var/packages/Git/target/webapi/SYNO.Git.lib /var/packages/Git/target/webapi/SYNO.Git.lib.bak sudo vi /var/packages/Git/target/webapi/SYNO.Git.lib 删掉appPriv 之后的SYNO.SDS.GIT.Instance 保存退出

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