在java项目中你可能会有以下需求：用户上传本地图片，然后展示在网页上。本篇文章将使用阿里云oss实现上传图片到oss，oss生成url。

一、准备工作

首先进入阿里云，按如下操作

进入创建页面，修改读写权限为公共读

然后进入bucket，创建AccessKey

创建后，保存好AccessKeyID和AccessKey Secret

二、代码

将以下依赖添加到项目的pom.xml文件中

<code><dependency>

<groupId>com.aliyun.oss</groupId>

<artifactId>aliyun-sdk-oss</artifactId>

<version>3.15.1</version>

</dependency>

<dependency>

<groupId>javax.xml.bind</groupId>

<artifactId>jaxb-api</artifactId>

<version>2.3.1</version>

</dependency>

<dependency>

<groupId>javax.activation</groupId>

<artifactId>activation</artifactId>

<version>1.1.1</version>

</dependency>

<!-- no more than 2.3.3-->

<dependency>

<groupId>org.glassfish.jaxb</groupId>

<artifactId>jaxb-runtime</artifactId>

<version>2.3.3</version>

</dependency>

创建一个工具类，用于配置aliyunoss

添加以下代码：（注意修改）

<code>import com.aliyun.oss.ClientException;

import com.aliyun.oss.OSS;

import com.aliyun.oss.OSSClientBuilder;

import com.aliyun.oss.OSSException;

import com.aliyun.oss.model.PutObjectRequest;

import com.aliyun.oss.model.PutObjectResult;

import java.io.FileInputStream;

import java.io.InputStream;

public class AliOssUtil {

// Endpoint以华东1（杭州）为例，其它Region请按实际情况填写。

private static final String ENPOINT = "地区";

// 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();

private static final String ACCESS_KEY_ID="你的ID";code>

private static final String ACCESS_KEY_SECRT="KEY";code>

// 填写Bucket名称，例如examplebucket。

private static final String BUCKETNAME = "你的bucket名称";

public static String uploadFile(String objectName, InputStream in) throws Exception {

// 创建OSSClient实例。

OSS ossClient = new OSSClientBuilder().build(ENPOINT,ACCESS_KEY_ID,ACCESS_KEY_SECRT);

String url = "";

try {

// 填写字符串。

String content = "Hello OSS，你好世界";

// 创建PutObjectRequest对象。

PutObjectRequest putObjectRequest = new PutObjectRequest(BUCKETNAME, objectName,in);

// 如果需要上传时设置存储类型和访问权限，请参考以下示例代码。

// ObjectMetadata metadata = new ObjectMetadata();

// metadata.setHeader(OSSHeaders.OSS_STORAGE_CLASS, StorageClass.Standard.toString());

// metadata.setObjectAcl(CannedAccessControlList.Private);

// putObjectRequest.setMetadata(metadata);

// 上传字符串。

PutObjectResult result = ossClient.putObject(putObjectRequest);

//url组成:http://bucket名称.区域节点

url = "https://" + BUCKETNAME + "." + ENPOINT.substring(ENPOINT.lastIndexOf("/")+1)+"/"+objectName;

} 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();

}

}

return url;

}

}

然后在控制类中使用

@RestController

public class FileUploadController {

@PostMapping("/upload")

public Result<String> upload(MultipartFile file) throws Exception {

String originalFilename = file.getOriginalFilename();

//保证文件名字唯一，防止文件覆盖

String filename = UUID.randomUUID().toString()+originalFilename.substring(originalFilename.lastIndexOf("."));

String url = AliOssUtil.uploadFile(filename,file.getInputStream());

return Result.success(url);

}

}

三、测试接口