aws s3 v4 sign

snippet.java

import com.amazonaws.HttpMethod;
import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.GeneratePresignedUrlRequest;

import java.net.URL;

public class Test {
    public static void main(String[] args) {
        String bjKey = "{bjKey}";
        String bjSecret = "{bjSecret}";
        String sgKey = "{sgKey}";
        String sgSecret = "{sgSecret}";
        BasicAWSCredentials creds = new BasicAWSCredentials(sgKey, sgSecret);
        AmazonS3 s3 = AmazonS3ClientBuilder.standard()
                .withCredentials(new AWSStaticCredentialsProvider(creds))
                .withRegion("ap-northeast-1")
                .build();
        java.util.Date expiration = new java.util.Date();
        long milliSeconds = expiration.getTime();
        milliSeconds += 1000 * 60 * 60; // Add 1 hour.
        expiration.setTime(milliSeconds);
        GeneratePresignedUrlRequest urlRequest = new GeneratePresignedUrlRequest("{bucketName}",
                "{objKey}");
        urlRequest.setMethod(HttpMethod.GET);
        urlRequest.setExpiration(expiration);
        URL url = s3.generatePresignedUrl(urlRequest);
        System.out.println(url.toString());
    }
}