redis clients lettuce lettuce_intro

Lettuce Introduction

Redis Developer Course	Redis Technical Support	Redis Enterprise Server

Redis Client for Java

Lettuce(레터스)는 많은 사이트에서 사용되고 있는 Java용 Redis Client 입니다.
Lettuce Jar 파일 받기: search.maven.org에서 lettuce를 검색하세요.
Lettuce Project Github,   문서(Wiki),   Lettuce 공식 홈페이지

Lettuce version
  4.4.2 2017년 11월 16일
  5.1.8 2019년 7월 30일
  5.3.4 2020년 9월 15일
  6.1.3 2021년 6월 22일
  6.1.7 2022년 3월 18일

• Lettuce-6.1.7, Redis-7.0.2 Example
• Lettuce-4.4.2, Redis-4.0.6 Example

Lettuce-6.1.7, Redis-7.0.2

Lettuce-6.1.7 설명 페이지 보기
Lettuce jar 파일 받기: lettuce-core-6.1.7.RELEASE-bin.zip

이클립스(eclipse 2022-03) 설정 1) jar 파일 복사: lettuce-core-6.1.7.RELEASE.jar, dependencies/* -> C:\eclipse\workspace2/libs/ 2) Create Project Menu: File -> New -> Java Project Project name: Lettuce JRE: javaSE-1.8 Finish 3) User Lib 만들기: Project name (우클릭) -> Properties -> Java Build Path -> Tab: Libraris -> Add Library -> User Library -> Next -> User Libraries -> New -> Add (External) JARS -> Apply and Close -> Finish

Main.java
import java.util.Scanner; import io.lettuce.core.RedisClient; import io.lettuce.core.api.StatefulRedisConnection; import io.lettuce.core.api.async.RedisAsyncCommands; import io.lettuce.core.api.sync.RedisCommands; public class Main { public static RedisClient redisClient = null; public static StatefulRedisConnection<String, String> connection = null; public static RedisCommands<String, String> syncCmd = null; // Sync용 command public static RedisAsyncCommands<String, String> asyncCmd = null; // Async용 command public static String conn = "redis://goodus@192.168.56.102:6379/0?timeout=1m"; public static void main(String[] args) { System.out.println("Hello Lettuce World"); System.out.println("Redis-7.0.2, Lettuce-6.1.7"); Scanner scanner = new Scanner(System.in); Util util = new Util(); redisConnect(); ping(); while(true) { System.out.println("1:STRING 2:LIST 3:SET 4:ZSET 5:HASH 6:COMMON KEYS\n"+ "7:ASYNC 8:Connection Pool 9:Pubsub"); System.out.println("선택(exit:99)> "); String input = scanner.nextLine(); int i = util.checkInt(input); switch (i) { case 1: new LettuceStringCmd(); break; case 2: new LettuceListCmd(); break; case 3: new LettuceSetCmd(); break; case 4: new LettuceZsetCmd(); break; case 5: new LettuceHashCmd(); break; case 6: new LettuceCommonCmd(); break; case 7: new LettuceAsyncCmd(); break; case 8: new LettuceConnPool(); break; case 9: new LettucePubsubCmd(); break; case 99: break; default: System.out.println("잘못 선택했습니다. 다시 선택하세요. "); } if (i==99) break; } scanner.close(); redisClose(); } public static void redisConnect() { try { redisClient = RedisClient.create(conn); connection = redisClient.connect(); syncCmd = connection.sync(); asyncCmd = connection.async(); } catch (Exception e) { System.out.println(e.getMessage()); return; } System.out.println("Redis Connection -> OK"); } public static void ping() { String ret = syncCmd.ping(); System.out.println(ret); } public static void redisClose() { connection.close(); redisClient.shutdown(); System.out.println("Redis Close -> OK"); } }
Util.java
import java.util.ArrayList; public class Util { public Util () { } public int checkInt(String val) { try { int i = Integer.parseInt(val); return i; } catch (NumberFormatException e) { return Integer.MIN_VALUE; } } public long checkLong(String val) { try { long l = Long.parseLong(val); return l; } catch (NumberFormatException e) { return Long.MIN_VALUE; } } public double checkDouble(String val) { try { double d = Double.parseDouble(val); return d; } catch (NumberFormatException e) { return Double.MIN_VALUE; } } // space(공란)이 여러개 있어도 처리하고 "str1 str2"도 한 단어로 처리한다. // https://code-examples.net/ko/q/335d89 public String[] split(String str) { str += " "; // To detect last token when not quoted... ArrayList<String> strings = new ArrayList<String>(); boolean inQuote = false; StringBuilder sb = new StringBuilder(); for (int i = 0; i < str.length(); i++) { char c = str.charAt(i); if (c == '"' || c == ' ' && !inQuote) { if (c == '"') inQuote = !inQuote; if (!inQuote && sb.length() > 0) { strings.add(sb.toString()); sb.delete(0, sb.length()); } } else sb.append(c); } return strings.toArray(new String[strings.size()]); } }

Lettuce-4.4.2, Redis-4.0.6

필요한 Jar 파일들

• lettuce-4.4.2.Final.jar
• netty-all-4.1.19.Final.jar
• rxjava-1.3.4.jar -> 화면에서 rxjava를 검색하세요. rxjava2 버전을 사용하면 에러가 발생합니다.
• commons-pool2-2.4.2.jar
• 이 파일들을 Libraries에 추가하세요.

Connection

Redis class를 만들어 아래 source code를 넣는다.   이후에는 Redis.syncCmd.set() 이렇게 사용한다.

• Lettuce client object 선언
  public static RedisClient redisClient = null; public static StatefulRedisConnection<String, String> connection = null; public static RedisCommands<String, String> syncCmd = null; // Sync용 command public static RedisAsyncCommands<String, String> asyncCmd = null; // Async용 command
• Connection string format: password@ip:port/db-no/timeout
  String conn1 = "redis://192.168.56.103:6000/0"; String conn2 = "redis://password@192.168.56.103:6000/0?timeout=5s"; RedisURI redisUri = new RedisURI("192.168.56.103", 6000, 5, TimeUnit.SECONDS);
• Connection
  try { redisClient = RedisClient.create(redisUri); } catch (Exception e) { System.out.println(e); return; } connection = redisClient.connect(); syncCmd = connection.sync(); asyncCmd = connection.async();
• Ping
  try { String ret = syncCmd.ping(); System.out.println("6000] ping -> "+ret); } catch (Exception e) { System.out.println(e); }
• Close
  connection.close(); redisClient.shutdown();