Guava

Efficient way to find the difference between two data sets

由 微笑、不失礼 提交于 2019-12-25 02:15:00
问题 I have two copies of data, here 1 represents my volumes and 2 represent my issues. I have to compare COPY2 with COPY1 and find all the elements which are missing in COPY2 ( COPY1 will always be a superset and COPY2 can be equal or will always be a subset). Now, I have to get the missing volume and the issue in COPY2. Such that from the following figure(scenario) I get the result as : - Missing files – 1-C, 1-D, 2-C, 2-C, 3-A, 3-B, 4,E. Question- What data structure should I use to store the

How to fix 'ClassCastException: cannot assign instance of' - Works local but not in standalone on cluster

由 匆匆过客 提交于 2019-12-25 01:32:15
问题 I have a Spring web application(built in maven) with which I connect to my spark cluster(4 workers and 1 master) and to my cassandra cluster(4 nodes). The application starts, the workers communicate with the master and the cassandra cluster is also running. However when I do a PCA(spark mllib) or any other calculation(clustering, pearson, spearman) through the interface of my web-app I get the following error: java.lang.ClassCastException: cannot assign instance of scala.collection.immutable

HashBiMap SerializationException or how to serialize classes where IsSerializable is not applicable?

由 狂风中的少年 提交于 2019-12-24 20:53:48
问题 Problem seems to be that not all Guava classes are serializable out-of-the-box. I found a quite good solution to this and like to share it. (in this case for HashBiMap). (Maybe some Guava developers may apply this one day to ideally all of the classes) If you copy the below class (and maybe adjust it to your to-be-serializable class) you will have further investigation details inside the Javadoc comment already. package com.google.common.collect; import java.util.LinkedHashMap; import java

Spring Boot 使用Caffeine缓存

由 本小妞迷上赌 提交于 2019-12-24 19:08:13
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> Spring Boot 使用Caffeine缓存 Caffeine官方的介绍 demo Caffeine配置参数 Caffeine是Java8重写Guava缓存，取代Guava缓存。 Spring Cache相关注解基础请查看这篇文章 Caffeine官方的介绍 caffeine官网 Caffeine是基于Java8的高性能，接近完美的缓存库。 demo pom.xml 引入spring-context-support <dependency> <groupId>com.github.ben-manes.caffeine</groupId> <artifactId>caffeine</artifactId> <version>2.8.0</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> </dependency> 1 2 3 4 5 6 7 8 9 或者spring-boot-starter-cache <dependency> <groupId>com.github.ben-manes.caffeine<

Unable to make Guava base64 encode/decode work

由 半腔热情 提交于 2019-12-24 16:14:03
问题 It seems there is a very silly mistake somewhere as the following hello-world program is not working for me. import com.google.common.io.BaseEncoding; import junit.framework.Test; import junit.framework.TestCase; import junit.framework.TestSuite; String hello = "hello"; junit.framework.Assert.assertEquals( hello.getBytes(), BaseEncoding.base64().decode( BaseEncoding.base64().encode(hello.getBytes()) ) ); I even tried hello.getBytes("ISO-8859-1") What am I missing? 回答1: Arrays (confusingly) do

Alternative to com.google.common.io.ByteArrayDataInput?

由 只谈情不闲聊 提交于 2019-12-24 15:17:43
问题 I'm currently using com.google.common.io.ByteArrayDataInput in my code. What I'm writing is a sort of loader for a binary file. Unfortunately, ByteArrayDataInput does not provide the information how many bytes left in its internal byte array. Is there any alternative to this class that provides such infomation? I know I can write my own wrapper class for com.google.common.io.ByteArrayDataInput , but I'd like to avoid that. EDIT The problem is that the reference to my com.google.common.io

Fast(er) comparison of longs in byte format?

由 末鹿安然 提交于 2019-12-24 15:01:38
问题 I have a key value store that has byte[] keys. Some of these keys will be used for longs (longs themselves, also Localdate and LocalTime instances). I have a nice clean comparator, using standard Java and Guava: @Override public int compare(byte[] left, byte[] right) { long leftLong = Longs.fromByteArray(left); long rightLong = Longs.fromByteArray(right); return Long.compare(leftLong, rightLong); } but it's slower than I would expect. Sorting 100,000 longs takes 100ms, whereas sorting 100,000

In PlayN, how can I get the HTML version of my project using Google's Guava libraries to compile?

由 ╄→尐↘猪︶ㄣ 提交于 2019-12-24 10:52:09
问题 I can run the Java version of my project fine by simply importing Guava libraries like so: import com.google.gwt.thirdparty.guava.common.collect.ImmutableList; Following the advice here, I've added this line to html/pom.xml: <dependency> <groupId>com.google.guava</groupId> <artifactId>guava-gwt</artifactId> <version>10.0.1</version> </dependency> And this line to html/project.gwt.xml file: <inherits name="com.google.common.collect.Collect"/> But when I try to GWT-Compile my HTML version in

How to sort a Map<Key, Value> on the values in Java with google collections ordering function

由 梦想的初衷 提交于 2019-12-24 09:31:10
问题 How to sort a map(?,B) on the values in Java with google collections ordering function, if B is a class, which has a field of type double, which should be used for ordering. 回答1: Here's a snippet that uses a generic method that takes a Map<K,V> and a Comparator<? super V> , and returns a SortedSet of its entrySet() sorted on the values using the comparator. public class MapSort { static <K,V> SortedSet<Map.Entry<K,V>> entriesSortedByValues(Map<K,V> map, final Comparator<? super V> comp) {

Java/Kotlin: Finding the intersection of multiple HashSets by class ID

由 只愿长相守 提交于 2019-12-24 08:57:15
问题 I'm having trouble finding the intersection of an Array of Hashed Sets that contain a data Class (where I want to intersect by identifier): class Protein(val id: String, val score: Double, val molw: Double, val spc: Int) I've pulled in some data from a .csv file into this type of structure: ArrayList<HashSet<Protein>> So I have six array lists [1 for each csv], each containing one hashed set that contains thousands of Protein structures. Here's what I've tried so far to get an intersection
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