从 R 连接到亚马逊红移时出错 - Windows 10

Question

使用 JDBC 函数将 R 连接到 amazon redshift（我使用的是 windows 10）时，出现以下错误：

Error in .jfindClass(as.character(driverClass)[1]) : class not found

我运行的代码是

install.packages("rJava")
install.packages("RJDBC")
library(rJava)
library(RJDBC)

download.file('http://s3.amazonaws.com/redshift-downloads/drivers/RedshiftJDBC41-1.1.13.1013.jar','RedshiftJDBC41-1.1.13.1013.jar')
driver <- JDBC("com.amazon.redshift.jdbc41.Driver", "RedshiftJDBC41-1.1.13.1013.jar", identifier.quote = "`")

要获取有关我运行此错误的更多信息：

 .jclassLoader()$setDebug(1L)

完整的错误跟踪是：

RJavaClassLoader: added 'RedshiftJDBC41-1.1.13.1013.jar' to the URL class path loader
RJavaClassLoader: adding Java archive file 'RedshiftJDBC41-1.1.13.1013.jar' to the internal class path
RJavaClassLoader: added 'C:/Users/user/Documents/R/win-library/3.2/RJDBC/java/RJDBC.jar' to the URL class path loader
RJavaClassLoader: adding Java archive file 'C:/Users/user/Documents/R/win-library/3.2/RJDBC/java/RJDBC.jar' to the internal class path
RJavaClassLoader@33909752.findClass(com.amazon.redshift.jdbc41.Driver)
 - URL loader did not find it: java.lang.ClassNotFoundException: com.amazon.redshift.jdbc41.Driver
RJavaClassLoader.findClass("com.amazon.redshift.jdbc41.Driver")
 - trying class path "C:\Users\user\Documents\R\win-library\3.2\rJava\java"
 Directory, can get 'C:\Users\user\Documents\R\win-library\3.2\rJava\java\com\amazon\redshift\jdbc41\Driver.class'? NO
 - trying class path "C:\Users\user\Documents\R\win-library\3.2\RJDBC\java\RJDBC.jar"
JAR file, can get 'com/amazon/redshift/jdbc41/Driver'? NO
- trying class path "C:\Users\user\Desktop\Pricing"
   Directory, can get 'C:\Users\user\Desktop\Pricing\com\amazon\redshift\jdbc41\Driver.class'? NO
- trying class path "C:\Users\user\Desktop\Pricing\RedshiftJDBC41-1.1.9.1009.jar"
JAR file, can get 'com/amazon/redshift/jdbc41/Driver'? NO
- trying class path "RedshiftJDBC41-1.1.9.1009.jar"
JAR file, can get 'com/amazon/redshift/jdbc41/Driver'? NO
- trying class path "." Directory, can get '.\com\amazon\redshift\jdbc41\Driver.class'? NO
- trying class path "C:\RedshiftJDBC41-1.1.9.1009.jar"
JAR file, can get 'com/amazon/redshift/jdbc41/Driver'? NO
- trying class path "RedshiftJDBC41-1.1.13.1013.jar"
JAR file, can get 'com/amazon/redshift/jdbc41/Driver'? NO
>> ClassNotFoundException 

如果您对可以提供帮助的东西有任何想法，那就太棒了！谢谢

Answer 1

完全相同的问题影响了我。出于某种原因，download.file() 抓取了一个损坏的 .jar。我们小组的开发人员发现了以下修复：

1. 省略：

   download.file('http://s3.amazonaws.com/redshift-downloads/drivers/RedshiftJDBC41-1.1.13.1013.jar','RedshiftJDBC41-1.1.13.1013.jar')

2. 直接从http://docs.aws.amazon.com/redshift/latest/mgmt/configure-jdbc-connection.html下载.jar

3. 将 .jar 复制到您的工作目录。

4. 运行剩余的代码。

Answer 2

我给你的建议是将 redshift 与 RPostgreSQL 包连接起来。

install.packages("RPostgreSQL")
library(RPostgreSQL)
drv <- dbDriver("PostgreSQL")
conn <-dbConnect(drv,host='host link',port='5439',dbname='dbname',user='xxx',password='yyy')
dbSendQuery(conn,"insert your query")

Answer 3

嗨，我指的是你的代码

install.packages("rJava") install.packages("RJDBC") 库（rJava） 库（RJDBC）

download.file('http://s3.amazonaws.com/redshift-downloads/drivers/RedshiftJDBC41-1.1.13.1013.jar','RedshiftJDBC41-1.1.13.1013.jar') driver <- JDBC("com.amazon.redshift.jdbc41.Driver", "RedshiftJDBC41-1.1.13.1013.jar", identifier.quote = "`")

你写驱动对象的地方，语法是

driver <- JDBC("CLASSNAME","PATH WHERE REDSHIFT JAR FILE IS DOWNLOADED')

我遇到了同样的错误，一旦我意识到我必须放置正确的路径，我就可以连接。 我对 JDBC 的第二个参数是 'C:\Users\person.name\Downloads\RedshiftJDBC41-1.1.13.1013.jar'

希望对你有帮助