java

问题 I'm having some trouble understanding streams. I've looked around and can't seem to find an example that matches my use case. I have an existing nested for loop: List<ObjectB> objectBs = new ArrayList<ObjectB>(); for (ObjectA objA: objectAList) { for (ObjectB objB: objA.getObjectBList()) { if (objB.getNumber() != 2) { objectBs.add(objB); } } } Alot of exampls show how to add objB.getNumber() to a list but not objB . 回答1: You can use flatMap to obtain a Stream<ObjectB> of all the ObjectB

问题 I'm getting the following error using TomEE and JPA: SEVERE: JAVA AGENT NOT INSTALLED. The JPA Persistence Provider requested installation of a ClassFileTransformer which requires a JavaAgent. See http://openejb.apache.org/3.0/javaagent.html Is having a java agent required for openJPA to function properly? (Specifically is it needed for "openjpa.jdbc.SynchronizeMappings") If so, how do I install it properly in eclipse? 回答1: -javaagent:openejb-javaagent-3.0-beta-2.jar Add that to your VM

问题 I want to compare two ArrayList of string arrays. List<String[]> list1 = new ArrayList<String[]>; List<String[]> list2 = new ArrayList<String[]>; list1.equals(list2); This will return false because equals method in ArrayList will do equals on the element. ListIterator<E> e1 = listIterator(); ListIterator<?> e2 = ((List<?>) o).listIterator(); while (e1.hasNext() && e2.hasNext()) { E o1 = e1.next(); Object o2 = e2.next(); if (!(o1==null ? o2==null : o1.equals(o2))) return false; } return !(e1

问题 Basically, I want to query if any mouse button is being pressed and if so, which one. The problem is that I don't use a (constantly focused) UI environment. It is meant to be able to run in the background while the OS is focused on another window. I just have a Swing GUI set up for easy controlling. How could I do this? (By the way, I am trying to query it inside of a loop, so setting up an event listener wouldn't be efficient.) 回答1: As mentioned by others you would need to use JNA in order

问题 Basically, I want to query if any mouse button is being pressed and if so, which one. The problem is that I don't use a (constantly focused) UI environment. It is meant to be able to run in the background while the OS is focused on another window. I just have a Swing GUI set up for easy controlling. How could I do this? (By the way, I am trying to query it inside of a loop, so setting up an event listener wouldn't be efficient.) 回答1: As mentioned by others you would need to use JNA in order

问题 In earlier spring boot, the configuration for setting up SSL security had to be done on application.properties by mentioning server.port=8443 security.require-ssl=true server.ssl.key-store=classpath:shq.jks server.ssl.key-store-password=****** server.ssl.key-password=****** Would the same work on spring boot 2.0.3 If not what has to be changed. 回答1: The answer for your question is YES. It is same for Spring boot 2.0.x versions also. you can refer below to cross verify the same. Enable HTTPS

问题 @FunctionalInterface public interface Runnable { public abstract void run(); } public class MethodReference1 { public static String ThreadStatus() { System.out.println( Thread.currentThread().getName() + " is running..."); return "threadname"; } public static void main(String[] args) { Thread t1 = new Thread(() -> ThreadStatus()); t1.start(); } } In the above example using Java 8, ThreadStatus() returns a string but Runnable interface "run()" method doesnt return any value. But it still works

问题 I implemented a tool and I want to make it open source. The problem is that my tool has some dependencies (binaries/. jar files). How can solve this problem, so that the person who downloads my source code, for example to extend it to a new feature, doesn't have to care of the dependencies? Should i write the dependencies in the MANIFEST as relative path, relative to my source code or something like that? 回答1: You can convert your project into a maven project and then put your source code to

问题 Below is my java udf code, package com.udf; import org.apache.spark.sql.api.java.UDF1; public class SparkUDF implements UDF1<String, String> { @Override public String call(String arg) throws Exception { if (validateString(arg)) return arg; return "INVALID"; } public static boolean validateString(String arg) { if (arg == null | arg.length() != 11) return false; else return true; } } I am building the Jar with this class as SparkUdf-1.0-SNAPSHOT.jar I am having a table name as sample in hive

问题 I implemented a tool and I want to make it open source. The problem is that my tool has some dependencies (binaries/. jar files). How can solve this problem, so that the person who downloads my source code, for example to extend it to a new feature, doesn't have to care of the dependencies? Should i write the dependencies in the MANIFEST as relative path, relative to my source code or something like that? 回答1: You can convert your project into a maven project and then put your source code to