Convert String variable to a List [Groovy]
def l = Eval.me(ids) Takes the string of groovy code (in this case “[10,1,9]”) and evaluates it as groovy. This will give you a list of 3 ints.
java
Sorting an ArrayList of Objects alphabetically
The sorting part can be done by implementing a custom Comparator<Vehicle>. Collections.sort(vehiclearray, new Comparator<Vehicle>() { public int compare(Vehicle v1, Vehicle v2) { return v1.getEmail().compareTo(v2.getEmail()); } }); This anonymous class will be used for sorting the Vehicle objects in the ArrayList on the base of their corresponding emails alphabetically. Upgrading to Java8 will let you also … Read more
How can I avoid ResultSet is closed exception in Java?
Sounds like you executed another statement in the same connection before traversing the result set from the first statement. If you’re nesting the processing of two result sets from the same database, you’re doing something wrong. The combination of those sets should be done on the database side.
How to deserialize JSON into flat, Map-like structure?
You can do this to traverse the tree and keep track of how deep you are to figure out dot notation property names: import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.node.ArrayNode; import com.fasterxml.jackson.databind.node.ObjectNode; import com.fasterxml.jackson.databind.node.ValueNode; import java.io.IOException; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import org.junit.Test; public class FlattenJson { String json = “{\n” + ” \”Port\”:\n” + … Read more
Java: removing numeric values from string
This will remove all digits: firstname1 = firstname1.replaceAll(“\\d”,””);
Java URL: Unknown Protocol “C”
You need to turn the path to the image.jpg file into a file:// URL, like this: String imageUrl = “file:///C:/Users/MyUser/image.jpg”; Otherwise it interprets the C as the URL protocol.
Reserved words as names or identifiers
This is a valid question. Such a thing is possible in other languages. In C#, prefix the identifier with @ (as asked before); in Delphi, prefix with &. But Java offers no such feature (partly because it doesn’t really need to interact with identifiers defined by other languages the way the .Net world does).
JSP: EL expression is not evaluated [duplicate]
I know it’s supposed to be on by default, but I run across pages now and again (or even the same page that changes behavior) where the EL processing doesn’t happen. Adding the following to the top of any such pages should resolve the issue: <%@ page isELIgnored=”false” %> I add it to every page … Read more
Why does List.remove(int) throw java.lang.UnsupportedOperationException? [duplicate]
You’re using it on a List implementation returned by Arrays.asList(), which returns a fixed-length collection, therefore a remove is unsupported.