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Java图片处理

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图片处理是OSS提供的海量、安全、低成本、高可靠的图片处理服务。原始图片上传到OSS后,您可以通过简单的RESTful接口,在任何时间、任何地点、任何互联网设备上对图片进行处理。

注意事项

  • 本文以华东1(杭州)外网Endpoint为例。如果您希望通过与OSS同地域的其他阿里云产品访问OSS,请使用内网Endpoint。关于OSS支持的Region与Endpoint的对应关系,请参见访问域名和数据中心

  • 本文以从环境变量读取访问凭证为例。如何配置访问凭证,请参见Java配置访问凭证

  • 本文以OSS域名新建OSSClient为例。如果您希望通过自定义域名、STS等方式新建OSSClient,请参见新建OSSClient

使用图片处理参数处理图片

  • 使用单个图片处理参数处理图片

    import com.aliyun.oss.*;
    import com.aliyun.oss.common.auth.*;
    import com.aliyun.oss.model.GetObjectRequest;
    import java.io.File;
    
    public class Demo {
        public static void main(String[] args) throws Throwable {
            // Endpoint以华东1(杭州)为例,其它Region请按实际情况填写。
            String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
            // 从环境变量中获取访问凭证。运行本代码示例之前,请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
            EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
            // 填写Bucket名称,例如examplebucket。
            String bucketName = "examplebucket";
            // 填写Object完整路径。Object完整路径中不能包含Bucket名称。
            String objectName = "exampleobject.jpg";
            // 填写本地文件的完整路径,例如D:\\localpath\\example-resize.jpg。如果指定的本地文件存在会覆盖,不存在则新建。
            String localPath = "D:\\localpath\\example-resize.jpg";
    
            // 创建OSSClient实例。
            OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);
    
            try {
                // 将图片缩放为固定宽高100 px。
                String style = "image/resize,m_fixed,w_100,h_100";
                GetObjectRequest request = new GetObjectRequest(bucketName, objectName);
                request.setProcess(style);
                // 将处理后的图片命名为example-resize.jpg并保存到本地。
                // 如果未指定本地路径只填写了本地文件名称(例如example-resize.jpg),则文件默认保存到示例程序所属项目对应本地路径中。
                ossClient.getObject(request, new File(localPath));
            } catch (OSSException oe) {
                System.out.println("Caught an OSSException, which means your request made it to OSS, "
                        + "but was rejected with an error response for some reason.");
                System.out.println("Error Message:" + oe.getErrorMessage());
                System.out.println("Error Code:" + oe.getErrorCode());
                System.out.println("Request ID:" + oe.getRequestId());
                System.out.println("Host ID:" + oe.getHostId());
            } catch (ClientException ce) {
                System.out.println("Caught an ClientException, which means the client encountered "
                        + "a serious internal problem while trying to communicate with OSS, "
                        + "such as not being able to access the network.");
                System.out.println("Error Message:" + ce.getMessage());
            } finally {
                if (ossClient != null) {
                    ossClient.shutdown();
                }
            }
        }
    }
  • 使用不同的图片处理参数处理图片

    import com.aliyun.oss.*;
    import com.aliyun.oss.common.auth.*;
    import com.aliyun.oss.model.GetObjectRequest;
    import java.io.File;
    
    public class Demo {
        public static void main(String[] args) throws Throwable {
            // Endpoint以华东1(杭州)为例,其它Region请按实际情况填写。
            String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
            // 从环境变量中获取访问凭证。运行本代码示例之前,请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
            EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
            // 填写Bucket名称,例如examplebucket。
            String bucketName = "examplebucket";
            // 填写Object完整路径。Object完整路径中不能包含Bucket名称。
            String objectName = "exampleobject.jpg";
    
            // 创建OSSClient实例。
            OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);
    
            try {
                // 将图片缩放为固定宽高100 px。
                String style = "image/resize,m_fixed,w_100,h_100";
                GetObjectRequest request = new GetObjectRequest(bucketName, objectName);
                request.setProcess(style);
                // 将处理后的图片命名为example-resize.jpg并保存到本地。
                // 填写本地文件的完整路径,例如D:\\localpath\\example-resize.jpg。如果指定的本地文件存在会覆盖,不存在则新建。
                // 如果未指定本地路径只填写了本地文件名称(例如example-resize.jpg),则文件默认保存到示例程序所属项目对应本地路径中。
                ossClient.getObject(request, new File("D:\\localpath\\example-resize.jpg"));
    
                // 从坐标(100,100)开始,将图片裁剪为宽高100 px。
                style = "image/crop,w_100,h_100,x_100,y_100";
                request = new GetObjectRequest(bucketName, objectName);
                request.setProcess(style);
                // 将处理后的图片命名为example-crop.jpg并保存到本地。
                ossClient.getObject(request, new File("D:\\localpath\\example-crop.jpg"));
    
                // 将图片旋转90°。
                style = "image/rotate,90";
                request = new GetObjectRequest(bucketName, objectName);
                request.setProcess(style);
                // 将处理后的图片命名为example-rotate.jpg并保存到本地。
                ossClient.getObject(request, new File("D:\\localpath\\example-rotate.jpg"));
    
                // 在图片中添加文字水印。
                // 文字水印的文字内容经过Base64编码后,再将编码结果中的加号(+)替换成短划线(-),正斜线(/)替换成下划线(_)并去掉尾部的等号(=),从而得到水印字符串。
                // 指定文字水印的文字内容为Hello World,文字内容进行编码处理后得到的水印字符串为SGVsbG8gV29ybGQ。
                style = "image/watermark,text_SGVsbG8gV29ybGQ";
                request = new GetObjectRequest(bucketName, objectName);
                request.setProcess(style);
                // 将处理后的图片命名为example-watermarktext.jpg并保存到本地。
                ossClient.getObject(request, new File("D:\\localpath\\example-watermarktext.jpg"));
    
                // 在图片中添加图片水印。请确保水印图片已保存在图片所在Bucket中。
                // 水印图片的完整路径经过Base64编码后,再将编码结果中的加号(+)替换成短划线(-),正斜线(/)替换成下划线(_)并去掉尾部的等号(=),从而得到水印字符串。
                // 指定水印图片的完整路径为panda.jpg,完整路径进行编码处理后得到的水印字符串为cGFuZGEuanBn。
                style = "image/watermark,image_cGFuZGEuanBn";
                request = new GetObjectRequest(bucketName, objectName);
                request.setProcess(style);
                // 将处理后的图片命名为example-watermarkimage.jpg并保存到本地。
                ossClient.getObject(request, new File("D:\\localpath\\example-watermarkimage.jpg"));
            } catch (OSSException oe) {
                System.out.println("Caught an OSSException, which means your request made it to OSS, "
                        + "but was rejected with an error response for some reason.");
                System.out.println("Error Message:" + oe.getErrorMessage());
                System.out.println("Error Code:" + oe.getErrorCode());
                System.out.println("Request ID:" + oe.getRequestId());
                System.out.println("Host ID:" + oe.getHostId());
            } catch (ClientException ce) {
                System.out.println("Caught an ClientException, which means the client encountered "
                        + "a serious internal problem while trying to communicate with OSS, "
                        + "such as not being able to access the network.");
                System.out.println("Error Message:" + ce.getMessage());
            } finally {
                if (ossClient != null) {
                    ossClient.shutdown();
                }
            }
        }
    }
  • 同时使用多个图片处理参数处理图片

    使用多个图片处理参数处理同一个图片时,sytle中的多个参数之间以正斜线(/)分隔。

    import com.aliyun.oss.*;
    import com.aliyun.oss.common.auth.*;
    import com.aliyun.oss.model.GetObjectRequest;
    import java.io.File;
    
    public class Demo {
        public static void main(String[] args) throws Throwable {
            // Endpoint以华东1(杭州)为例,其它Region请按实际情况填写。
            String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
            // 从环境变量中获取访问凭证。运行本代码示例之前,请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
            EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
            // 填写Bucket名称,例如examplebucket。
            String bucketName = "examplebucket";
            // 填写Object完整路径。Object完整路径中不能包含Bucket名称。
            String objectName = "exampleobject.jpg";
            // 填写本地文件的完整路径,例如D:\\localpath\\example-new.jpg。如果指定的本地文件存在会覆盖,不存在则新建。
            String pathName = "D:\\localpath\\example-new.jpg";
    
            // 创建OSSClient实例。
            OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);
    
            try {
                // 将图片缩放为固定宽高100 px后,再旋转90°。
                String style = "image/resize,m_fixed,w_100,h_100/rotate,90";
                GetObjectRequest request = new GetObjectRequest(bucketName, objectName);
                request.setProcess(style);
                // 将处理后的图片命名为example-new.jpg并保存到本地。
                // 如果未指定本地路径只填写了文件名称(例如example-new.jpg),则文件默认保存到示例程序所属项目对应本地路径中。
                ossClient.getObject(request, new File("D:\\localpath\\example-new.jpg"));
            } catch (OSSException oe) {
                System.out.println("Caught an OSSException, which means your request made it to OSS, "
                        + "but was rejected with an error response for some reason.");
                System.out.println("Error Message:" + oe.getErrorMessage());
                System.out.println("Error Code:" + oe.getErrorCode());
                System.out.println("Request ID:" + oe.getRequestId());
                System.out.println("Host ID:" + oe.getHostId());
            } catch (ClientException ce) {
                System.out.println("Caught an ClientException, which means the client encountered "
                        + "a serious internal problem while trying to communicate with OSS, "
                        + "such as not being able to access the network.");
                System.out.println("Error Message:" + ce.getMessage());
            } finally {
                if (ossClient != null) {
                    ossClient.shutdown();
                }
            }
        }
    }

使用图片样式处理图片

您可以通过OSS管理控制台创建图片样式将多个图片处理参数封装在一个样式中,然后使用样式批量处理图片。具体操作,请参见图片样式

以下代码展示了使用图片样式处理图片。

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.model.GetObjectRequest;
import java.io.File;

public class Demo {
    public static void main(String[] args) throws Throwable {
        // Endpoint以华东1(杭州)为例,其它Region请按实际情况填写。
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // 从环境变量中获取访问凭证。运行本代码示例之前,请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // 填写Bucket名称,例如examplebucket。
        String bucketName = "examplebucket";
        // 填写Object完整路径。Object完整路径中不能包含Bucket名称。
        String objectName = "exampleobject.jpg";
        // 填写本地文件的完整路径,例如D:\\localpath\\example-new.jpg。如果指定的本地文件存在会覆盖,不存在则新建。
        String pathName = "D:\\localpath\\example-new.jpg";

        // 创建OSSClient实例。
        OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);

        try {
            // 使用自定义样式处理图片。
            // yourCustomStyleName填写通过OSS管理控制台创建的图片样式名称。
            String style = "style/yourCustomStyleName";
            GetObjectRequest request = new GetObjectRequest(bucketName, objectName);
            request.setProcess(style);
            // 将处理后的图片命名为example-new.jpg并保存到本地。
            // 如果未指定本地路径只填写了文件名称(例如example-new.jpg),则文件默认保存到示例程序所属项目对应本地路径中。
            ossClient.getObject(request, new File(pathName));
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}

图片处理持久化

图片处理服务默认不保存处理后的图片,您可以通过ImgSaveAs接口将图片保存到原图片所在存储空间。

以下代码展示了图片处理持久化操作。

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.common.utils.BinaryUtil;
import com.aliyun.oss.common.utils.IOUtils;
import com.aliyun.oss.model.GenericResult;
import com.aliyun.oss.model.ProcessObjectRequest;
import java.util.Formatter;

public class Demo {
    public static void main(String[] args) throws Throwable {
        // Endpoint以华东1(杭州)为例,其它Region请按实际情况填写。
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // 从环境变量中获取访问凭证。运行本代码示例之前,请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // 填写Bucket名称,例如examplebucket。
        String bucketName = "examplebucket";
        // 填写Object完整路径。Object完整路径中不能包含Bucket名称。
        String sourceImage = "exampleimage.png";

        // 创建OSSClient实例。
        OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);

        try {
            // 将图片缩放为固定宽高100 px。
            StringBuilder sbStyle = new StringBuilder();
            Formatter styleFormatter = new Formatter(sbStyle);
            String styleType = "image/resize,m_fixed,w_100,h_100";
            // 将处理后的图片命名为example-resize.png并保存到当前Bucket。
            // 填写Object完整路径。Object完整路径中不能包含Bucket名称。
            String targetImage = "example-resize.png";
            styleFormatter.format("%s|sys/saveas,o_%s,b_%s", styleType,
                    BinaryUtil.toBase64String(targetImage.getBytes()),
                    BinaryUtil.toBase64String(bucketName.getBytes()));
            System.out.println(sbStyle.toString());
            ProcessObjectRequest request = new ProcessObjectRequest(bucketName, sourceImage, sbStyle.toString());
            GenericResult processResult = ossClient.processObject(request);
            String json = IOUtils.readStreamAsString(processResult.getResponse().getContent(), "UTF-8");
            processResult.getResponse().getContent().close();
            System.out.println(json);
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}

生成带图片处理参数的文件签名URL

私有文件的访问URL带有签名。OSS不支持在带签名的URL后直接添加图片处理参数。如果您想要对私有文件进行图片处理,需要将图片处理参数加入到签名中,相关的代码示例如下:

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.model.GeneratePresignedUrlRequest;
import java.net.URL;
import java.util.Date;

public class Demo {
    public static void main(String[] args) throws Throwable {
        // Endpoint以华东1(杭州)为例,其它Region请按实际情况填写。
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // 从环境变量中获取访问凭证。运行本代码示例之前,请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // 填写Bucket名称,例如examplebucket。
        String bucketName = "examplebucket";
        // 填写Object完整路径。Object完整路径中不能包含Bucket名称。
        String objectName = "exampleobject.jpg";

        // 创建OSSClient实例。
        OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);

        try {
            // 将图片缩放为固定宽高100 px后,再旋转90°。
            String style = "image/resize,m_fixed,w_100,h_100/rotate,90";
            // 指定签名URL过期时间为10分钟。
            Date expiration = new Date(new Date().getTime() + 1000 * 60 * 10 );
            GeneratePresignedUrlRequest req = new GeneratePresignedUrlRequest(bucketName, objectName, HttpMethod.GET);
            req.setExpiration(expiration);
            req.setProcess(style);
            URL signedUrl = ossClient.generatePresignedUrl(req);
            System.out.println(signedUrl);
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}

图片处理工具

您可以通过可视化图片处理工具ImageStyleViewer直观地看到OSS图片处理结果。

相关文档

  • 关于图片处理支持的参数说明,请参见处理参数

  • 关于图片处理的完整示例代码,请参见GitHub示例

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