collections

问题 I need to pass a collection to a JAVA SOURCE in the oracle database. This is the illustration of the current setup without collection where oracle varchar2 is mapped to java String and it is working fine The code below:- The java source:- import java.io.*; public class Test_java extends Object{ public static String print_test(String test) throws Exception { try{ System.out.println(test); return "UP"; } catch(Exception e) { return "DOWN" + e.getMessage(); } } }; The invoking function:- CREATE

问题 I'm searching for a fast and convenient way to add save() and rollback() to a standard Map. Let's say i have an object 'table' of class Table which in turn has a private Map called 'rows'. What I'm trying to achieve is a fast and without memory waste method for Row to do something like: row = new Row(); table.addRow(row).setValue("col1", "foo").setValue("col2", "bar").save(); row.setValue("col2", "beer"); System.out.println(table.getRows()); // 1. col1=foo, col2=bar row.save(); System.out

问题 I'm searching for a fast and convenient way to add save() and rollback() to a standard Map. Let's say i have an object 'table' of class Table which in turn has a private Map called 'rows'. What I'm trying to achieve is a fast and without memory waste method for Row to do something like: row = new Row(); table.addRow(row).setValue("col1", "foo").setValue("col2", "bar").save(); row.setValue("col2", "beer"); System.out.println(table.getRows()); // 1. col1=foo, col2=bar row.save(); System.out

问题 I think I can't see the forest for the trees... How do I test for equality (not identity) of all elements recursively in a List of String arrays? Here's a minimal example: List<String[]> left = new ArrayList<>(); left.add(new String[]{"one", "two"}); List<String[]> right = new ArrayList<>(); right.add(new String[]{"one", "two"}); System.out.println(left.equals(right) ? "Yeah!" : "This is not what I want."); I want to use this in unit tests. A bit more context: I have a class that holds

问题 I was using Multiset to have easy access to the freq of elements, but I realize there is Collections#frequency(Collection<?>, Object) that does the same for any collection. What is the point of using Multiset then? Is performance an issue here? 回答1: Guava documentation for Multiset#count() has to say: Note that for an Object.equals(java.lang.Object)-based multiset, this gives the same result as Collections.frequency(java.util.Collection, java.lang.Object) (which would presumably perform more

问题 I was using Multiset to have easy access to the freq of elements, but I realize there is Collections#frequency(Collection<?>, Object) that does the same for any collection. What is the point of using Multiset then? Is performance an issue here? 回答1: Guava documentation for Multiset#count() has to say: Note that for an Object.equals(java.lang.Object)-based multiset, this gives the same result as Collections.frequency(java.util.Collection, java.lang.Object) (which would presumably perform more

问题 Is there a Kotlin stdlib function to find the symmetric difference between two sets? So given two sets [1, 2, 3] and [1, 3, 5] the symmetric difference would be [2, 5] . I've written this extension function which works fine, but it feels like an operation that should already exist within the collections framework. fun <T> Set<T>.symmetricDifference(other: Set<T>): Set<T> { val mine = this subtract other val theirs = other subtract this return mine union theirs } EDIT: What is the best way get

问题 Is there a Kotlin stdlib function to find the symmetric difference between two sets? So given two sets [1, 2, 3] and [1, 3, 5] the symmetric difference would be [2, 5] . I've written this extension function which works fine, but it feels like an operation that should already exist within the collections framework. fun <T> Set<T>.symmetricDifference(other: Set<T>): Set<T> { val mine = this subtract other val theirs = other subtract this return mine union theirs } EDIT: What is the best way get

问题 Code: sortedgroups = sorted(metagroups, key=lambda group: group[-1]) categories = map(operator.itemgetter(-1), sortedgroups) categorycounts = collections.Counter(categories) print('Writing output files') with open('report.txt', 'a+') as f: for category in categories: f.write(category + '\n') So this code works if I comment out: categorycounts = collections.Counter(categories) The for loop seems to break if I try to count the amounts of same strings in the categories list. Does collections

问题 Get the details of a Shipment with the expected date of delivery. Also get the number of shipment status available for that shipment, meaning the number of intermediate traversals. Write a program to compare if the expected date on the final status of the shipment and the actual expected date of the Shipment and display whether the Shipment has arrived 'on time' or 'before' or 'after' the expected date. public class ShipmentMain { public static void main(String[] args) { DateFormat df =