Java Kuche Day memo

Java Kuche Day memo

2018/12/8 (Sat) 13: 00-18: 00

CODEBASE

Proto solution management

Programming class: HTML / JS / Ruby (1000 hours)

Intern

Beta version hackathon

Practitioner event (AWS / Android)

Event recruitment / coworking space opening

Oracle Code One Report (Mr. Ito)

Java One.

Exhibited from Fujitsu / Rakuten

40 to 50 participants (Japanese), 10 sessions (presenter is free of charge)

Also with Oracle Open World

Pre-registration date + 4 days session

9:06

Session Information

Oracle policy

Open Java and open paid functions

Innovate

Ecosystem support

JDK11 commits

2500 cases / 500 organizations (Red Hat, Google, etc.)

2000 commits (Oracle)

Java in a World of Containers

The JDK is so big that it's hard to get into the container

Java runtime customization

JDK (530MB)-> Very heavy

-> Create a custom JDK using Jigsaw

Full (300MB)-> java.base only (48MB)

OS minutes 250MB-> slim version further optimized

Project Portola

• Further reduction of HotSpot

• minimal VM

• 5MB ultra-lightweight VM
• Minimum compliance with Java SE specifications
• For research?

20MB Hello World

Monolith vs Microservice

Monolith

• Deploy per application

Microservice

• Divide by multiple functions

• It is difficult to identify errors due to a string of dependencies.

• Open Tracing

• Log output / tracking is difficult

JDK Flight Recoder

• Completely save error logs, etc.
• Free from JDK11

JDK new release model explanation (Mr. Ito)

JDK 11 API document Japanese version released

Installation documents etc. will be released one by one

How to make Oracle JDK (conventional)

• Open JDK (source code only, GPL)
• Oracle JDK (binary. FX, installer, etc. added. BCL)
• Quaternary security updates from Oracle to Open
• Incomplete security update synchronization
• No function addition until version update (added together)

BCL

• Non-commercial replication possible only within the company

from now on

• Oracle also publishes Open JDK binaries

• GPL
• OpenJDK built as it is
• Versions released in March and September (additional features only)
• Security updates in January, April, July and October
• No LTS
• With security update

• Oracle JDK also provided

• Updated once every 3 years (minimum 8 years of support) LTS
• Also updated every 6 months
• Meet the need for long-term fixed versions
• Paid
• Commercial development and operation?
• Free for some uses

• Significant changes to the Oracle JDK 11 license
• For internal or personal development / testing / demo use
  • OTNLA for Oracle Java SE
• Source code from Open JDK
• Functions are added in small steps

JDK 12 Early Access version released

Features to be removed

Described in the release notes Removed API

Deleted in a minimum of 1 year (2 versions)

Non-Corporate

JDK 8 license

Oracle JDK available until 2020 for personal use only

Java SE Subscription

What is offered

• Support window
• Commercial license and long term support
• Commercial features and tools
• Compatible with all hardware that can run Java
• Price structure

• Java SE Desktop Subscription --For desktop --Number x number of people ―― 3600 yen / (year / person)
• Java SE Subscription

• For servers
• Number of units x number of people
• 36000 yen / (year / person)

For details, Publish Slide is performed on Slide Share.

Twitter 4J (Mr. Yamamoto)

Received Duke's Choice Award

Received the Japan OSS Encouragement Award

Duke's Choice Award

Given to those who have contributed to Java technology

4th time in Japan

Receive a conference pass trophy (wooden)

Recruitment from May to August

Application using Web form (free)

Twitter 4J

Java library that wraps the Twitter API

Usage record of major companies

11th year this year

100,000 DLs a month

Third self-recommendation

Practical Library Design

About exception handling

Large amount of information (advantages / disadvantages)

It takes time to identify the cause

Ingenuity

• Enter the version number

• Fingerprint (Twitter Exception)

• Calculate the hash referenced from each of the class name / method name and line number

Now of Spring Framework (Tsuhako)

Spring One + Oracle Code One Report

Spring One

2019 will be held in Texas

Spring Framework

A collection of Java frameworks

2004～

1.x Web-based framework

4.x Spring Boot

4.3 Support until 2020

5.x

• JDK 8 or above
• Kotlin support
• Reacting programming model

5.1 Java 11 support

5.2

• Released next year
• Supports Java 12 and Kotlin 1.3
• Fully compatible with Graal VM

Spring WebFlux

• Resource usage optimization

JDK12

Amber

325：Swiching Expressions

Comma separated case

• Easy to read when slewing without break

Lambda-style notation

• You can write code without break

Return value added to Switch statement

• Compile error without default label

Return value in break statement is possible

• Cannot be used in combination with Lambda style notation

326：Raw String Literals

Until now, a lot of literals were needed to write a path

Added literals with backticks

• Line breaks and escape characters can be written raw

Blockchain (Mr. Otani)

circulation

Blockchain basics

Blockchain

• How distributed computers work
• No administrator required
• Public blockchain (global)
• Private blockchain
• Identify users by address

• Manage addresses with accounts and apps

• All transactions are recorded in blocks
• Cannot be tampered with
• Data and processes are transparent
• You can reduce the trouble of international remittance --It is also a hotbed for Maneron
• Does self-cleaning work?

• Price fixing
• Publication of pornography
• Cannot be deleted (even confidential information cannot be deleted)

• Price volatility

Time to reach consensus

• Bitcoin takes 10 minutes
• 15 seconds with Eathereum
• Payment layer, Lighting NertWork, etc. are proposed

Mining

• Calculation to make a chain
• The first person to solve is rewarded

Gas cost

• Costs paid to miners
• It may cost several hundred yen at a time

Smart contract

• Run the program on the blockchain

token

• Mechanism for defining value --Monetization (virtual currency, etc.) --Securitization

Security

--Manage security with "key" --Enormous management cost

Hard fork

• Split occurs when specifications change

• Suspension of deposit and withdrawal
• Difficult to handle in accounting (because the user has tokens on both)

Nation x Blockchain (Estonia)

• Estcoin will be issued

Local government x blockchain (Kaga City)

• Blockchain City Declaration

Initiatives using blockchain

Aragon

• You can create a virtual company
• Representing the basic functions of the organization

COLONY

• Create a team on the blockchain
• Assign members to tasks

Blocklancer

• Ordering of projects

• Trial issues with the ordering party

• Keep reviews fair

• Transparency of labor contracts

• Procedure for changing labor contract

• Use Solidity

Points considered in development

dApps

• Make the most of blockchain technology

Web apps

• Web technology available
• Only a few blockchain technologies

Wallet

• Easy user management and fee collection
• Inconvenient

Use of management address

• Highly convenient
• Gas cost to operate

GO is convenient for operating Ethereum!

Many engineers learn

Difficult to predict numerical values as a business

Difficult to receive external security diagnosis

Oracle Code One Java SE Update (Mr. Sakuraba)

Java Champion

There are 4 people in Japan

Is Jetbrains IDE Free?

Moscone Center

Move OpenJDK to GitHub?

Java is still free

Presenter uses emacs (does not use IDE)

#WorksLikeHeavenOnJDK11

JEP

Normal

• Completion

Preview

• 90% complete
• JVM

Incubator

• A little more
• API

Experimental

• It still takes

Preview / Incubator will be official version in 1 and 2 versions

Amber

Loom

Panama

Valhara

Local Variable Type interface

• Local variable type inference
• Inference from the right side
• Actually, there is type inference from java 5

• There was type inference in generics and lambda expressions

• Compatible types can be reassigned
• ArrayList cannot be assigned to List.of ()
• Style Guidlines

• Make a variable name with useful information
• The initializer has enough information depending on the reader

• Style FAQ
• The collection of diamond operator / argumentless of becomes \