要求:

1. java1.8以上
2. Maven: 这里的version指定了一个版本范围，每次更新pom.xml的时候会尝试去下载7.5.x版本中的最新版本，你可以手动指定一个固定的版本。

<dependency>
  <groupId>com.qiniu</groupId>
  <artifactId>qiniu-java-sdk</artifactId>
  <version>[7.5.0, 7.5.99]</version>
</dependency>

3. Java SDK依赖的第三方库及其版本如下：

<dependencies>
    <dependency>
      <groupId>com.squareup.okhttp3</groupId>
      <artifactId>okhttp</artifactId>
      <version>3.14.2</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>com.google.code.gson</groupId>
      <artifactId>gson</artifactId>
      <version>2.8.5</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>com.qiniu</groupId>
      <artifactId>happy-dns-java</artifactId>
      <version>0.1.6</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
  </dependencies>

其中关于Region对象和机房的关系如下：

官网参考：

https://developer.qiniu.com/kodo/1239/java#1

七牛云工具类

import com.google.gson.Gson;
import com.qiniu.common.QiniuException;
import com.qiniu.common.Zone;
import com.qiniu.http.Response;
import com.qiniu.storage.BucketManager;
import com.qiniu.storage.Configuration;
import com.qiniu.storage.UploadManager;
import com.qiniu.storage.model.DefaultPutRet;
import com.qiniu.util.Auth;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;

/**
 * 七牛云工具类
 */
public class QiniuUtils {
    //设置好账号的ACCESS_KEY和SECRET_KEY
    public  static String accessKey = "your access_key";//这两个登录七牛 密匙管理页面可以找到
    public  static String secretKey = "your secret_key";
    //要上传的空间名
    public  static String bucket = "carefree-project";

    public static void upload2Qiniu(String filePath,String fileName){
        //构造一个带指定Zone对象的配置类（区域需根据 自己七牛云的对象存储区域选择）
        Configuration cfg = new Configuration(Zone.zone2());//Zone.zone2() 表示华南区域 
        UploadManager uploadManager = new UploadManager(cfg);
        Auth auth = Auth.create(accessKey, secretKey);
        String upToken = auth.uploadToken(bucket);
        try {
            Response response = uploadManager.put(filePath, fileName, upToken);
            //解析上传成功的结果
            DefaultPutRet putRet = new Gson().fromJson(response.bodyString(), DefaultPutRet.class);
        } catch (QiniuException ex) {
            Response r = ex.response;
            try {
                System.err.println(r.bodyString());
            } catch (QiniuException ex2) {
                //ignore
            }
        }
    }

    //上传文件
    public static void upload2Qiniu(byte[] bytes, String fileName){
        //构造一个带指定Zone对象的配置类
        Configuration cfg = new Configuration(Zone.zone2());
        //...其他参数参考类注释
        UploadManager uploadManager = new UploadManager(cfg);

        //默认不指定key的情况下，以文件内容的hash值作为文件名
        String key = fileName;
        Auth auth = Auth.create(accessKey, secretKey);
        String upToken = auth.uploadToken(bucket);
        try {
            Response response = uploadManager.put(bytes, key, upToken);
            //解析上传成功的结果
            DefaultPutRet putRet = new Gson().fromJson(response.bodyString(), DefaultPutRet.class);
            System.out.println(putRet.key);
            System.out.println(putRet.hash);
        } catch (QiniuException ex) {
            Response r = ex.response;
            System.err.println(r.toString());
            try {
                System.err.println(r.bodyString());
            } catch (QiniuException ex2) {
                //ignore
            }
        }
    }

    //删除文件
    public static void deleteFileFromQiniu(String fileName){
        //构造一个带指定Zone对象的配置类
        Configuration cfg = new Configuration(Zone.zone2());
        String key = fileName;
        Auth auth = Auth.create(accessKey, secretKey);
        BucketManager bucketManager = new BucketManager(auth, cfg);
        try {
            bucketManager.delete(bucket, key);
        } catch (QiniuException ex) {
            //如果遇到异常，说明删除失败
            System.err.println(ex.code());
            System.err.println(ex.response.toString());
        }
    }
}