liudong

import java.security.KeyPairGenerator;
import java.security.KeyPair;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.KeyFactory;
import java.security.spec.EncodedKeySpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.security.spec.InvalidKeySpecException;
import java.security.NoSuchAlgorithmException;

psayre23

Below are the Big O performance of common functions of different Java Collections.


List                 | Add  | Remove | Get  | Contains | Next | Data Structure
---------------------|------|--------|------|----------|------|---------------
ArrayList            | O(1) |  O(n)  | O(1) |   O(n)   | O(1) | Array
LinkedList           | O(1) |  O(1)  | O(n) |   O(n)   | O(1) | Linked List
CopyOnWriteArrayList | O(n) |  O(n)  | O(1) |   O(n)   | O(1) | Array

raineorshine

Find: function ([A-Z])
Replace: function \l\1

Find: \.(.)([^(\n]*)\(
Replace: .\l\1\2(

LeCoupa

# Redis Cheatsheet
# All the commands you need to know


redis-server /path/redis.conf  # start redis with the related configuration file
redis-cli                      # opens a redis prompt


# Strings.

jonico

#!groovy
import groovy.json.JsonOutput
import groovy.json.JsonSlurper

def label = "mypod-${UUID.randomUUID().toString()}"
podTemplate(label: label, yaml: """
spec:
      containers:
      - name: mvn
        image: maven:3.3.9-jdk-8

jeffbrl

# This example is from https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-sub.html.
UserData:
  Fn::Base64:
    !Sub |
      #!/bin/bash -xe
      yum update -y aws-cfn-bootstrap
      /opt/aws/bin/cfn-init -v --stack ${AWS::StackName} --resource LaunchConfig --configsets wordpress_install --region ${AWS::Region}
      /opt/aws/bin/cfn-signal -e $? --stack ${AWS::StackName} --resource WebServerGroup --region ${AWS::Region}

antoinedelia

How to make pandas as an AWS layer

1. Install pandas to local directory with pip: pip install -t . pandas

2. Remove pandas and numpy directories rm -r pandas numpy

3. Download the Linux distribution for pandas (choose the Python version that you want to use): https://pypi.org/project/pandas/#files

4. Download the Linux distribution for numpy (must be the same as the pandas one): https://pypi.org/project/numpy/#files