小编use*_*629的帖子

我如何在比赛结束后抓住第一个单词？

例如,一旦我找到Car,我该如何抓住Chevy？

public class NewExtractDemo {
    public static void main(String[] args) {
        String input = "I have the following Car: Chevy, Truck: Ford, Van: Honda";

        Pattern p = Pattern.compile("(Car|Truck|Van)");
        Matcher m = p.matcher(input);

        List<String> Search = new ArrayList<String>();
        while (m.find()) {
            System.out.println("Found a " + m.group() + ".");
            Search.add(m.group());
        }
    }
}

我正在尝试根据我在线阅读的内容连接到AWS Athena,但我遇到了问题.

采取的步骤

• 更新Java
• 用accesskey/secretKey替换user/pass
• 用user/pass传递accesskey/secretKey

有任何想法吗？

错误信息:

.jcall中的错误(drv @ jdrv,"Ljava/sql/Connection;","connect",as.character(url)[1],:java.sql.SQLException:必须提供AWS accessId/secretKey或AWS凭证提供程序

系统信息

  sysname                           release                                       version 
  "Linux"                           "4.4.0-62-generic"      "#83-Ubuntu SMP Wed Jan 18 14:10:15 UTC 2017" 
  nodename                          machine                                        login
 "ip-***-**-**-***"                 "x86_64"                                      "unknown" 
  user                              effective_user 
 "rstudio"                          "rstudio"

代码https://www.r-bloggers.com/interacting-with-amazon-athena-from-r/

library(RJDBC)

URL <- 'https://s3.amazonaws.com/athena-downloads/drivers/AthenaJDBC41-1.0.0.jar'
fil <- basename(URL)
if (!file.exists(fil)) download.file(URL, fil)

drv <- JDBC(driverClass="com.amazonaws.athena.jdbc.AthenaDriver", fil, identifier.quote="'")

con <- jdbcConnection <- dbConnect(drv, 'jdbc:awsathena://athena.us-east-1.amazonaws.com:443/',
                                   s3_staging_dir="s3://mybucket",
                                   user=Sys.getenv("myuser"),
                                   password=Sys.getenv("mypassword"))

如果我有这样的数组,我怎么能循环并将计数推入一个新数组？
所有的帮助都会成功!

    var Products = [
    ['Product A'],
    ['Product A'],
    ['Product A'],
    ['Product A'],
    ['Product A'],
    ['Product B'],
    ['Product B'],
    ['Product B'],
    ['Product B'],
    ['Product B'],
    ['Product B'],
    ['Product B'],
    ['Product B'],    
    ['Product B'],
    ['Old Product B'],
    ['Old Product B'],
    ['Old Product B'],
    ['Old Product B'],
    ['Old Product B'],
    ['Old Product]
         ];

最终目标:

        var UniqueProducts = [
    ['Product A',5],
    ['Product B',6],
    ['Old Product B',9]
     ];