Spring Boot配置随機數

Spring Boot支援在系統加載的時候配置随機數。

添加config/random.properties檔案，添加以下内容：

#随機32位MD5字元串
user.random.secret=${random.value}

#随機int數字
user.random.intNumber=${random.int}

#随機long數字
user.random.longNumber=${random.long}

#随便uuid
user.random.uuid=${random.uuid}

#随機10以内的數字
user.random.lessTen=${random.int(10)}

#随機1024~65536之内的數字
user.random.range=${random.int[1024,65536]}      

添加綁定類：

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;

@Component
@ConfigurationProperties(prefix = "user.random")
@PropertySource(value = { "config/random.properties" })
public class RandomConfig {

    private String secret;
    private int intNumber;
    private int lessTen;
    private int range;
    private long longNumber;
    private String uuid;

    public String getSecret() {
        return secret;
    }

    public void setSecret(String secret) {
        this.secret = secret;
    }

    public int getIntNumber() {
        return intNumber;
    }

    public void setIntNumber(int intNumber) {
        this.intNumber = intNumber;
    }

    public int getLessTen() {
        return lessTen;
    }

    public void setLessTen(int lessTen) {
        this.lessTen = lessTen;
    }

    public int getRange() {
        return range;
    }

    public void setRange(int range) {
        this.range = range;
    }

    public long getLongNumber() {
        return longNumber;
    }

    public void setLongNumber(long longNumber) {
        this.longNumber = longNumber;
    }

    public String getUuid() {
        return uuid;
    }

    public void setUuid(String uuid) {
        this.uuid = uuid;
    }

}      

輸出如下：

secret=83a5c3402ef936a37842dc6de3d1af0f
intNumber=1816149855
lessTen=1
range=37625
longNumber=8449008776720010146
uuid=e5bc2091-1599-45b1-abd7-e3721ac77e6b      

具體的生成細節可以參考Spring Boot的配置類：

org.springframework.boot.context.config.RandomValuePropertySource