connection

问题 We in the process of migrating from MySql to MariaDB due to licensing/commercial usage reasons. We have successfully replaced the MySql connector jar with MariaDB client jar (first change) and are now trying to replace MySql server with MariaDB server without changing the data files. All our applications run perfectly for about 8-12 hours after which we see the following exception: org.springframework.transaction.CannotCreateTransactionException: Could not open Hibernate Session for

问题 I have mongodb where my data is stored. I am using SPSS where I have do some data analysis. Can someone help me in connecting SPSS to mongodb. Thank you. 回答1: Are you using SPSS Modeler or Statistics? In both cases you can access MongoDB using R. Both Statistics and Modeler have integration with R. So you can just use the R package 'rmongodb' and connect to your MongoDB. Here you have some links: https://docs.compose.io/languages/r.html http://www.r-bloggers.com/r-and-mongodb/ Remember to use

问题 I have my Spring Hibernate web application running on MySQL that gives me trouble. I have searched around and tried different configurations, read quite a few threads on this website, but it still pops up its smiling head. The error message is: Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 63,313,144 milliseconds ago. The last packet sent successfully to the server was 63,313,144 milliseconds ago. is longer than

问题 Service A calls into service B via HTTP. This happens frequently, and the size of transferred data is not very big. I discovered that re-using the same TCP connection to send multiple requests from A to B seems to improve latency. Naturally, the idea of connection pooling comes to mind: Open multiple connections to service B and keep them alive When A needs to make a call to B, provide it with one of the connections from the pool Implementing this involves solving some problems which are

问题 I tried to connect to my remote MySQL database, but I failed and got this error. com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The confusion is that It was effective when I used MySQL-Front tool to connect the remote database, and I can ping to the IP address successfully. but when I used my code, it wound show the error after about ten seconds. Also when I used the wrong username or password in my code, it wound show the wrong verification immediately.

问题 I have been playing around with the bluetooth API for Android 2.2 (API level 8, HTC Desire) and had an app connecting to an embedded Bluetooth device using: device.createRfcommSocketToServiceRecord(DEV_UUID); This generated a pairing request as expected, however to streamline the connection process I wanted to avoid the user interaction when pairing so moved to API level 10 (HTC Desire with CyanogenMod 7) so I could use: device.createInsecureRfcommSocketToServiceRecord(DEV_UUID); When testing

问题 I'm facing problem connection to API with using IP address. Even I had add the following code to plist, it still show error as below: "http://xx3.xx.xx8.xx7/xxx/xxx/ error: The resource could not be loaded because the App Transport Security policy requires the use of a secure connection." This is the code I add to the plist <key>xx3.xx.xx8.xx7</key> <dict> <key>NSThirdPartyExceptionMinimumTLSVersion</key> <string>TLSv1.1</string> <key>NSThirdPartyExceptionRequiresForwardSecrecy</key> <false/>

问题 I have three projects. One is a WCF Services Project, one is a WPF Project, and one is a Microsoft Unit Testing Project. I setup the WCF Services project with a data object that looks like this: [DataContract] public enum Priority { Low, Medium, High } [DataContract] public struct TimeInfo { [DataMember] public Int16 EstimatedHours { get; set; } [DataMember] public Int16 ActualHours { get; set; } [DataMember] public DateTime StartDate { get; set; } [DataMember] public DateTime EndDate { get;

问题 It seems that the ResultSet will be automatically closed when I close the Connection . But I want to return the ResultSet and use it in another method, then I don't know where to close Connection and PreparedStatement . public ResultSet executeQuery(String sql, String[] getValue) { Connection conn = null; PreparedStatement pstmt = null; ResultSet rs = null; try { conn = getConn(); pstmt = conn.prepareStatement(sql); if (getValue != null) { for (int i = 0; i < getValue.length; i++) { pstmt

问题 I am trying to connect with database using jdbc in java file. It is not connecting at all and giving me the error constantly "Something went wrong"; I guess it is because of the port number because all other data such as username, password and other code seems correct. I want to check the default port number so that I can try it properly. I did try using all three of these 8080, 80 and 3306 but it shows me error. Here port 8080 is used for HTTP server, 3306 is supposed to be default from the