在build.gradle中引入依赖

// 腾讯云oss
compile ('com.qcloud:cos_api:5.4.9'){
    exclude group:'org.slf4j',module:'slf4j-log4j12'
}

在grails-app/conf下创建一个application-oss.yml文件

oss:
    secretId: AKI**************************H7Ti
    secretKey: FN**************************Ns
    regionName: ap-chengdu
    bucket: img-555231231
    accessAddr: http://www.baidu.com # 访问地址

然后在application.yml中加入

spring:
    profiles:
        include: oss

新建一个TencentConfig的JavaBean类

package first.blood.cn.tools.oss.tencent;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;
/**
 * 腾讯云oss初始化配置
 * @Author Lee
 * @Description
 * @Date 2018年11月18日 18:51
 */
@Configuration
@ConfigurationProperties(prefix = "oss")
public class TencentConfig {
    private String secretId;
    private String secretKey;
    private String regionName;
    private String bucket;
    //访问时的域名
    private String accessAddr;
    public String getAccessAddr() {
        return accessAddr;
    }
    public void setAccessAddr(String accessAddr) {
        this.accessAddr = accessAddr;
    }
    public String getSecretId() {
        return secretId;
    }
    public void setSecretId(String secretId) {
        this.secretId = secretId;
    }
    public String getSecretKey() {
        return secretKey;
    }
    public void setSecretKey(String secretKey) {
        this.secretKey = secretKey;
    }
    public String getRegionName() {
        return regionName;
    }
    public void setRegionName(String regionName) {
        this.regionName = regionName;
    }
    public String getBucket() {
        return bucket;
    }
    public void setBucket(String bucket) {
        this.bucket = bucket;
    }
}

接下来创建一个文件上传的配置类（工具类）TencentOss

• 与前面的TencentConfig放在一个包下

package first.blood.cn.tools.oss.tencent;
import com.qcloud.cos.COSClient;
import com.qcloud.cos.ClientConfig;
import com.qcloud.cos.auth.BasicCOSCredentials;
import com.qcloud.cos.auth.COSCredentials;
import com.qcloud.cos.model.ObjectMetadata;
import com.qcloud.cos.model.PutObjectResult;
import com.qcloud.cos.region.Region;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import java.io.IOException;
import java.io.InputStream;
/**
 * @Author Lee
 * @Description
 * @Date 2018年11月18日 18:35
 */
@Component
public class TencentOss {
    @Autowired
    private TencentConfig tc;
    /**
     * 上传至腾讯云COS
     *
     * @param inputStream 输入流
     * @param fileName    保存路径+文件名：/2018/11/21/demo.png
     * @param contentType 文件类型，默认是 application/octet-stream
     * @return
     */
    public String upload(InputStream inputStream, String fileName) throws IOException {
        COSClient cosClient = null;
        try {
            // 1 初始化用户身份信息(secretId, secretKey)
            COSCredentials cred = new BasicCOSCredentials(tc.getSecretId(), tc.getSecretKey());
            // 2 设置bucket的区域, COS地域的简称请参照 https://cloud.tencent.com/document/product/436/6224
            // clientConfig中包含了设置region, https(默认http), 超时, 代理等set方法, 使用可参见源码或者接口文档FAQ中说明
            ClientConfig clientConfig = new ClientConfig(new Region(tc.getRegionName()));
            // 配置使用https
            // 3 生成cos客户端
            cosClient = new COSClient(cred, clientConfig);
            // bucket的命名规则为{name}-{appid} ，此处填写的存储桶名称必须为此格式
            String bucketName = tc.getBucket();
            ObjectMetadata objectMetadata = new ObjectMetadata();
            PutObjectResult putObjectResult = cosClient.putObject(bucketName, fileName, inputStream, objectMetadata);
            String etag = putObjectResult.getETag();
        } finally {
            if (inputStream != null) {
                inputStream.close();
            }
            if (cosClient != null) {
                cosClient.shutdown();
            }
        }
        return tc.getAccessAddr() + "/" + fileName;
    }
}

然后在程序入口类上加上@ComponetScan注解

package first.blood
import grails.boot.GrailsApp
import grails.boot.config.GrailsAutoConfiguration
import org.springframework.context.annotation.ComponentScan
@ComponentScan
class Application extends GrailsAutoConfiguration {
    static void main(String[] args) {
        GrailsApp.run(Application, args)
    }
}

控制器方法

/**
 *  单文件上传
 * @return
 */
def imgFile() {
    def map = [success: 0, message: "上传失败"]
    def file = null
    def inputStream = null
    try {
        file = params["editormd-image-file"]
        inputStream = file.getInputStream()
        String fileName = file.getOriginalFilename()
        if (!file && !fileName) {
            map.message = "请选择图片文件"
            render map as JSON
            return
        }
        // 判断文件大小，MAX_POST_SIZE自己定义
        if (file.getSize() > MAX_POST_SIZE) {
            map.message = "只能上传不超过2M的图片文件"
            render map as JSON
            return
        }
        // 判断是否是图片文件
        if (!ImgUtils.isImage(file.getInputStream())) {
            map.message = "只允许上传图片文件"
            render map as JSON
            return
        }
        String prefix = fileName.substring(fileName.lastIndexOf("."))
        // 新文件名，这里调用Date工具类生成目录结构2018/12/30
        String newFileName = DateUtils.getUrl() + "/" + UUIDUtils.id() + prefix
        String accessAddr = oss.upload(inputStream,newFileName)
        map.success = 1
        map.message = "上传成功"
        map.url = accessAddr
    } catch (e) {
        log.error("文件上传失败，msg={}", e)
        map.message = "请检查参数是否正确，只能上传不超过2M的图片文件"
    }
    render map as JSON
}

踩坑注意事项

1. 文件流只能用一次
   1. 前面定义了inputStream在中途用过一次就会出问题，上传的文件只有几B大小，有的是0B