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版权声明:本文由 低调小熊猫 发表于 低调小熊猫的博客
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文章链接:https://aodeng.cc/archives/javaosszipdown

简介

阿里oss对象存储官方文档我看了,但是真实开发,还不能满足需求,阿里文件下载路径只能写死,下载文件也只能单个下载,所以自己整理了一些代码,下载时可以自己选择保存的路径,可以实现多个文件同时下载,不吹逼了,反正很厉害就是了,话不多说,上代码

代码

1.自己封装的工具包的代码
https://aodeng.cc/archives/ossutil
2.页面发送请求的代码

<td>
<a class="btn btn-mini btn-danger" style="width: 88px;height:30px;margin-top: -25px" 
href="${pageContext.request.contextPath}/pproject/ossdownfile?projectId=${projectId}">
下载
</a>
</td>

3.功能实现的代码

/**
     * oss文件下载
     */
    @RequestMapping("/ossdownfile")  
    public void ossdownfile(HttpServletRequest request,HttpServletResponse response,@RequestParam(value="projectId",required=false) long projectId) throws Exception{ 
        try {
            //-----------------------低调小熊猫批量下载文件------------------------//
            //获取文件名称
            String Name=pprojectService.findOne(projectId).getCheckFileName();
            //模拟文件
            String fileName = request.getSession().getServletContext().getRealPath("tmp/check/")+"/"+projectId+"/"+Name;  
            // 创建临时文件
            File zipFile = File.createTempFile("temp", ".zip");
            FileOutputStream fps = new FileOutputStream(zipFile);
            CheckedOutputStream csum = new CheckedOutputStream(fps, new Adler32());//注释一下Adler32(较快)和CRC32两种
            // 用于将数据压缩成Zip文件格式
            ZipOutputStream zos = new ZipOutputStream(csum);
            //获取文件的name并拼接成key,下载文件
            File f = new File(PathUtil.getRealPath()+"\\tmp\\files\\"+projectId);
            if(f.exists()){
                File[] fs = f.listFiles();
                if(null!=fs){
                    for(File file0:fs){
                        //善意的提醒一下,key不能以任何形式的斜杠开头
                        InputStream inputStream = ossUtil.getObjectForInputStream("files/"+projectId+"/"+file0.getName()).getObjectContent();
                        zos.putNextEntry(new ZipEntry(file0.getName()));//确保压缩包里面文件不同名
                        int bytesRead = 0;
                        // 向压缩文件中输出数据
                        while((bytesRead=inputStream.read())!=-1){
                            zos.write(bytesRead);
                        }
                        inputStream.close();
                        zos.closeEntry();
                    }                    
                }
            }
            zos.close();
            //转码,免得文件名中文乱码  
            Name = URLEncoder.encode(Name,"UTF-8");  
            //设置文件下载头  
            response.addHeader("Content-Disposition", "attachment;filename=" + Name);    
            //1.设置文件ContentType类型,这样设置,会自动判断下载文件类型    
            response.setContentType("application/octet-stream");
            //写入文件
            FileInputStream fis = new FileInputStream(zipFile);
            BufferedInputStream buff = new BufferedInputStream(fis);
            BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream()); 
            //通知浏览器以附件形式下载            
            response.setHeader("Content-Disposition","attachment;filename="+URLEncoder.encode(Name,"utf-8"));
            byte[] car=new byte[1024];
            int L=0;
            while (L < zipFile.length()) {
                int j = buff.read(car, 0, 1024);
                L += j;
                out.write(car, 0, j);
            }
            if(out!=null){
                out.flush();
                out.close();
            }
            ossUtil.clientShutdown();
            // 删除文件
            zipFile.delete();
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }

善意的提示

出现这个bug的时候,其实就是连接池关闭的错误:

com.aliyun.oss.common.comm.ServiceClient Unable to execute HTTP request: Connection pool shut down

这句代码记得注释掉

client.shutdown();

创建的ossclient一旦关闭,就不可以继续使用。另外,多个ossclient实例之间是没有影响的,关闭任意一个,其余的实例不受影响。使用多线程的方式可以同时开启多个连接池,这样关闭才是没有影响的

下面是两个测试Case,第一个case不断的创建、关闭,测试是OK的,第二个case会出现异常信息。

        public void testMuliInstanceClient() throws Exception { 

        Thread thrd0 = new Thread(new Runnable() { 
            final String keyPrefix = "thread0-"; 

            @Override 
            public void run() { 
                for (int i = 0; i < 100; i++) { 
                    OSSClient client0 = new OSSClient(SECOND_ENDPOINT, SECOND_ACCESS_ID, SECOND_ACCESS_KEY); 
                    InputStream content = TestUtils.genFixedLengthInputStream(128 * 1024); 
                    String key = TestUtils.buildObjectKey(keyPrefix, i); 

                    try { 
                        PutObjectResult result = client0.putObject(bucketName, key, content, null); 
                        System.out.println(key + ": " + result.getETag()); 
                    } catch (Exception e) { 
                        e.printStackTrace(); 
                    } finally { 
                        if (client0 != null) { 
                            System.out.println("shutdown"); 
                            client0.shutdown(); 
                        } 
                    } 
                } 
            } 

        }); 

        Thread thrd1 = new Thread(new Runnable() { 
            final String keyPrefix = "thread1-"; 

            @Override 
            public void run() { 
                for (int i = 0; i < 100; i++) { 
                    OSSClient client1 = new OSSClient(SECOND_ENDPOINT, SECOND_ACCESS_ID, SECOND_ACCESS_KEY); 
                    InputStream content = TestUtils.genFixedLengthInputStream(1 * 1024 * 1024); 
                    String key = TestUtils.buildObjectKey(keyPrefix, i); 

                    try { 
                        PutObjectResult result = client1.putObject(bucketName, key, content, null); 
                        System.out.println(key + ": " + result.getETag()); 
                        Thread.sleep(50); 
                    } catch (Exception e) { 
                        e.printStackTrace(); 
                    } finally { 
                        if (client1 != null) { 
                            System.out.println("shutdown"); 
                            client1.shutdown(); 
                        } 
                    } 
                } 
            } 

        }); 

        thrd0.start(); 
        thrd1.start(); 
        thrd0.join(); 
        thrd1.join(); 

    } 

    @Test 
    public void keepUsingAfterClose() { 
        OSSClient client = new OSSClient(SECOND_ENDPOINT, SECOND_ACCESS_ID, SECOND_ACCESS_KEY); 
        InputStream content = TestUtils.genFixedLengthInputStream(128 * 1024); 
        client.putObject(bucketName, "key0", content, null); 

        client.shutdown(); 

        content = TestUtils.genFixedLengthInputStream(128 * 1024); 
        try { 
            client.putObject(bucketName, "key0", content, null); 
        } catch (ClientException ce) { 
            System.out.println(ce.getMessage()); 
        } catch (Exception e) { 
            System.out.println(e.getMessage()); 
        } 
    }