简单我想使用PNG / JPEG /位图文件应用图像压缩。
Android我们Bitmap.CompressFormat压缩我们的位图文件并用于进一步操作。
Bitmap.CompressFormat类允许以3种格式压缩，如下所示：
我的查询是我想以下列格式压缩文件：
我找到了一些图像压缩库，如ImageIo＆amp; ImageMagick但没有取得任何成功。我想使用此文件在AmazonServer上传。请指导我如何实现这一点，或者是否有任何其他选项可以在亚马逊服务器上传图像。
感谢您的时间。
答案 0 :(得分：0)
我不知道那些文件的压缩，但我创建了这个类，以编程方式将文件上传到使用Amazon SDK API的Amazon s3存储桶中：
package com.amazon.util;
import com.amazonaws.AmazonClientException;
import com.amazonaws.auth.PropertiesCredentials;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.model.CannedAccessControlList;
import com.amazonaws.services.s3.model.ObjectMetadata;
import com.amazonaws.services.s3.model.PutObjectRequest;
import com.amazonaws.services.s3.model.PutObjectResult;
import com.amazonaws.services.s3.model.S3ObjectSummary;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class AmazonS3Files {
private static final String existingBucketName = "bucketName";
private final String strProperties = "accessKey = MYACESSKEY \n"
+ "secretKey = my+secret+key";
private static final String urlRegion = "https://s3.amazonaws.com/";
public static final String urlPathS3 = urlRegion + existingBucketName;
public String UploadFile(InputStream inFile, String pathDocument, String fileName) {
return UploadFile(inFile, pathDocument, fileName, false);
}
public void deleteObjectsInFolder(String folderPath) {
InputStream inputStreamCredentials = new ByteArrayInputStream(strProperties.getBytes());
folderPath = folderPath.replace('\\', '/');
if (folderPath.charAt(folderPath.length() - 1) == '/') {
folderPath = folderPath.substring(0, folderPath.length() - 1);
}
if (folderPath.charAt(0) == '/') {
folderPath = folderPath.substring(1, folderPath.length());
}
try {
AmazonS3 s3Client = new AmazonS3Client(new PropertiesCredentials(inputStreamCredentials));
for (S3ObjectSummary file : s3Client.listObjects(existingBucketName, folderPath).getObjectSummaries()) {
s3Client.deleteObject(existingBucketName, file.getKey());
}
} catch (IOException | AmazonClientException e) {
System.out.println(e);
}
}
public void deleteFile(String filePath) {
InputStream inputStreamCredentials = new ByteArrayInputStream(strProperties.getBytes());
filePath = filePath.replace('\\', '/');
if (filePath.charAt(0) == '/') {
filePath = filePath.substring(1, filePath.length());
}
try {
AmazonS3 s3Client = new AmazonS3Client(new PropertiesCredentials(inputStreamCredentials));
s3Client.deleteObject(existingBucketName, filePath);
} catch (IOException | AmazonClientException e) {
System.out.println(e);
}
}
public String UploadFile(InputStream inFile, String pathDocument, String fileName, boolean bOverwiteFile) {
InputStream inputStreamCredentials = new ByteArrayInputStream(strProperties.getBytes());
String amazonFileUploadLocationOriginal;
String strFileExtension = fileName.substring(fileName.lastIndexOf("."), fileName.length());
fileName = fileName.substring(0, fileName.lastIndexOf("."));
fileName = fileName.replaceAll("[^A-Za-z0-9]", "");
fileName = fileName + strFileExtension;
pathDocument = pathDocument.replace('\\', '/');
try {
if (pathDocument.charAt(pathDocument.length() - 1) == '/') {
pathDocument = pathDocument.substring(0, pathDocument.length() - 1);
}
if (pathDocument.charAt(0) == '/') {
pathDocument = pathDocument.substring(1, pathDocument.length());
}
amazonFileUploadLocationOriginal = existingBucketName + "/" + pathDocument;
AmazonS3 s3Client = new AmazonS3Client(new PropertiesCredentials(inputStreamCredentials));
s3Client.setRegion(Region.getRegion(Regions.SA_EAST_1));
ObjectMetadata objectMetadata = new ObjectMetadata();
objectMetadata.setContentLength(inFile.available());
if (!bOverwiteFile) {
boolean bFileServerexists = true;
int tmpIntEnum = 0;
while (bFileServerexists) {
String tmpStrFile = fileName;
if (tmpIntEnum > 0) {
tmpStrFile = fileName.substring(0, fileName.lastIndexOf(".")) + "(" + tmpIntEnum + ")" + fileName.substring(fileName.lastIndexOf("."), fileName.length());
}
if (!serverFileExists(urlRegion + amazonFileUploadLocationOriginal + "/" + tmpStrFile)) {
bFileServerexists = false;
fileName = tmpStrFile;
}
tmpIntEnum++;
}
}
String strFileType = fileName.substring(fileName.lastIndexOf("."), fileName.length());
if (strFileType.toUpperCase().equals(".jpg".toUpperCase())) {
objectMetadata.setContentType("image/jpeg");
} else if (strFileType.toUpperCase().equals(".png".toUpperCase())) {
objectMetadata.setContentType("image/png");
} else if (strFileType.toUpperCase().equals(".gif".toUpperCase())) {
objectMetadata.setContentType("image/gif");
} else if (strFileType.toUpperCase().equals(".gmap".toUpperCase())) {
objectMetadata.setContentType("text/plain");
}
PutObjectRequest putObjectRequest = new PutObjectRequest(amazonFileUploadLocationOriginal, fileName, inFile, objectMetadata).withCannedAcl(CannedAccessControlList.PublicRead);
PutObjectResult result = s3Client.putObject(putObjectRequest);
return "/" + pathDocument + "/" + fileName;
} catch (Exception e) {
// TODO: handle exception
return null;
}
}
public boolean serverFileExists(String URLName) {
try {
HttpURLConnection.setFollowRedirects(false);
HttpURLConnection con =
(HttpURLConnection) new URL(URLName).openConnection();
con.setRequestMethod("HEAD");
return (con.getResponseCode() == HttpURLConnection.HTTP_OK);
} catch (Exception e) {
e.printStackTrace();
return false;
}
}
}
用于您的文件：
BufferedImage img = null;
try {
img = ImageIO.read(new File("file.jpg"));
String strReturn = AmazonS3Files.UploadFile(new ByteArrayInputStream(((DataBufferByte)(img).getRaster().getDataBuffer()).getData()), "path/to/file", "newfilename.jpg"); //Returns null if the upload doesn't work or the s3 file path of the uploaded file
} catch (IOException e) {
//Handle Exception
}