Springboot最佳实践：构建短url

<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://maven.apache.org/POM/4.0.0"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <!-- project properties -->
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.springboot.redis.tinyurl</groupId>
    <artifactId>SpringbootTinyUrl</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.1.RELEASE</version>
    </parent>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>commons-validator</groupId>
            <artifactId>commons-validator</artifactId>
            <version>1.7</version>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>18.0</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            </dependency>
    </dependencies>
    <build>
        <!-- to make the application as fat jar so that spring boot libraries are
            included -->
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

# Application configuration.
## You can change the server port configuration as per their configuration idea.
server.port=10091
# Redis configuration.
## As we are running Redis on Docker we are setting up its configuration.
spring.redis.host=localhost
spring.redis.port=6379

package com.springboot.redis.tinyurl;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@Slf4j
@SpringBootApplication
public class Runner {
    public static void main(String[] args) {
        SpringApplication.run(Runner.class, args);
        log.info("Springboot and tinyurl application started successfully.");
    }
}

package com.springboot.redis.tinyurl.model;
import com.google.common.hash.Hashing;
import lombok.AllArgsConstructor;
import lombok.Getter;
import java.nio.charset.StandardCharsets;
import java.time.LocalDateTime;
@Getter
@AllArgsConstructor
public class UrlDto {
    private final String id;
    private final String url;
    private final LocalDateTime created;
    public static UrlDto create(final String url) {
        final String id = Hashing.murmur3_32().hashString(url, StandardCharsets.UTF_8).toString();
        return new UrlDto(id, url, LocalDateTime.now());
    }
}

package com.springboot.redis.tinyurl.config;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.springboot.redis.tinyurl.model.UrlDto;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
@Configuration
public class RedisConfig {
    @Autowired
    private ObjectMapper objectMapper;
    @Autowired
    private RedisConnectionFactory redisConnectionFactory;
    // Setting up the Redis template object.
    @SuppressWarnings({"rawtypes", "unchecked"})
    @Bean
    public RedisTemplate<String, UrlDto> redisTemplate() {
        final Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(UrlDto.class);
        jackson2JsonRedisSerializer.setObjectMapper(objectMapper);
        final RedisTemplate<String, UrlDto> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(jackson2JsonRedisSerializer);
        return redisTemplate;
    }
}

package com.springboot.redis.tinyurl.controller;
import com.springboot.redis.tinyurl.exception.TinyUrlError;
import com.springboot.redis.tinyurl.model.UrlDto;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.validator.routines.UrlValidator;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.util.Objects;
import java.util.concurrent.TimeUnit;
@Slf4j
@RestController
@RequestMapping(value = "/rest/url")
public class TinyUrlController {
    @Autowired
    private RedisTemplate<String, UrlDto> redisTemplate;
    @Value("${redis.ttl}")
    private long ttl;
    @PostMapping
    public ResponseEntity create(@RequestBody final String url) {
        // Using commons-validator library to validate the input URL.
        final UrlValidator urlValidator = new UrlValidator(new String[]{"http", "https"});
        if (!urlValidator.isValid(url)) {
            // Invalid url return HTTP 400 bad request.
            return ResponseEntity.badRequest().body(new TinyUrlError("Invalid URL."));
        }
        // If valid URL, generate a hash key using guava's murmur3 hashing algorithm.
        final UrlDto urlDto = UrlDto.create(url);
        log.info("URL id generated = {}", urlDto.getId());
        // Store both hasing key and url object in redis.
        redisTemplate.opsForValue().set(urlDto.getId(), urlDto, ttl, TimeUnit.SECONDS);
        // Return the generated id as a response header.
        return ResponseEntity.noContent().header("id", urlDto.getId()).build();
    }
    @GetMapping(value = "/{id}")
    public ResponseEntity getUrl(@PathVariable final String id) {
        // Get from redis.
        final UrlDto urlDto = redisTemplate.opsForValue().get(id);
        if (Objects.isNull(urlDto)) {
            return ResponseEntity.status(HttpStatus.NOT_FOUND).body(new TinyUrlError("No such key exists."));
        } else {
            log.info("URL retrieved = {}", urlDto.getUrl());
        }
        return ResponseEntity.ok(urlDto);
    }
}