一.最近做阿里云oss文件上传开发，一点收获分享给大家，帮助大家绕过一些坑。关于阿里云oss服务的介绍，我这里不做赘述了，可以查看阿里云OSS开发api文档。
在这里我主要介绍下，文件上传流程比较复杂的服务器设置回调功能。整个流程图是这样的：
大家可以参考阿里api文档介绍的工作流程说明：https://help.aliyun.com/document_detail/31927.html?spm=5176.doc31988.6.633.OTY557
二. 客户端请求policy，签名，key以及回调地址等
1.首先定义我们的业务类型biz_type，主要是将文件按业务类型目录存储。这里我要着重强调一下，阿里oss回调请求的自定义参数：
${x:biz_type}，不要使用驼峰法命名，在开发的工程中，发现驼峰法命名bizType 取不到值。建议需要命名时 用"_"取代。
2.accessId ，accesskey 定义在properties文件中，这些定值从文件中读取，这里我要说明下：定义的end 和 endPoint
endpoint = http://oss-cn-shanghai.aliyuncs.com
end = oss-cn-shanghai.aliyuncs.com
bucket 是定义的桶名称就类似于文件目录名称。
2. callbackurl 定义自己的回调方法
3.签名，失效时间，policy，这些是根据阿里云官网提供的案例代码写的。
4.在定义callback字符串时，遇到一个大坑，这也是我写整篇文章的原因。
定义callback 时，阿里支持两种方式，一个是callbackBody字符串直接拼接 用&符连接。
这里我使用的是第二种方式，callbackBody 采用json字符串。但是这跟以往的字符串不一样，中间有阿里自带的字符bucket,object,size等以及自定义的字符，ali oss 需要解析自定义字符，这里可以理解成
变量的一个占位符，那么json串是如何拼接一个占位符变量呢？？？带着这个问题，我就一遍一遍的拼串，尝试了大概有两小时，看了官网的一篇错误排查文章：https://yq.aliyun.com/articles/68863/
定义的回调字符串是这样的：
{
"callbackUrl" : "http://abc.com/test.php",
"callbackHost" : "oss-cn-hangzhou.aliyuncs.com",
"callbackBody" : "{\"bucket\":${mimeType}, \"object\":${object},\"size\":${size},\"mimeType\":${mimeType},\"my_var\":${x:my_var}}",
"callbackBodyType" : "application/json"
}
顿时眼睛亮了，callbackBody 定义的原来是一个字符串的jsonobject,一直以为需要定义一个占位符类型的jsonobject对象。
然后继续拼串，定义的callbackBody就是这样："{\'bucket\':${bucket}, \'object\':${object},\'size\':${size},\'mimeType\':${mimeType},\'uid\':${x:uid},\'biz_type\':${x:biz_type}}"
最终将 resMap 转成json 字符返回。
public String reqOssServer() throws ServletException, IOException {
String[] bizArray = new String[]{"","user-dir/","advise-dir/"};
String biz_type = getRequest().getParameter("biz_type");
String sysCurrtime = System.currentTimeMillis()+"";
//15位随机码
String randStr = sysCurrtime.substring(5,sysCurrtime.length())+CommonUtil.getRamdon(15);
//目录
String dir = bizArray[Integer.valueOf(biz_type)];
PropertiesUtil pro = new PropertiesUtil("oss.properties");
String end = pro.readValue("end");
String endpoint = pro.readValue("endpoint");
String accessId = pro.readValue("accessKeyId");
String accessKey = pro.readValue("accessKeySecret");
String bucket = pro.readValue("bucketName");
String host = "https://" + bucket + "." + end;
//oss 回调地址
String callbackurl = Cont.TEST_DOMAIN_NAME+"/osscallback";
OSSClient client = new OSSClient(endpoint, accessId, accessKey);
try {
long expireTime = 3000;
long expireEndTime = System.currentTimeMillis() + expireTime * 100;
Date expiration = new Date(expireEndTime);
PolicyConditions policyConds = new PolicyConditions();
policyConds.addConditionItem(PolicyConditions.COND_CONTENT_LENGTH_RANGE, 0, 1048576000);
policyConds.addConditionItem(MatchMode.StartWith, PolicyConditions.COND_KEY, dir);
String postPolicy = client.generatePostPolicy(expiration, policyConds);
byte[] binaryData = postPolicy.getBytes("utf-8");
String encodedPolicy = BinaryUtil.toBase64String(binaryData);
String postSignature = client.calculatePostSignature(postPolicy);
Map<String, String> respMap = new LinkedHashMap<String, String>();
URL url = client.generatePresignedUrl(bucket, accessKey, expiration);
respMap.put("accessid", accessId);
respMap.put("policy", encodedPolicy);
respMap.put("signature", postSignature);
//respMap.put("expire", formatISO8601Date(expiration));
respMap.put("dir", dir);
respMap.put("host", host);
respMap.put("expire", String.valueOf(expireEndTime / 1000));
respMap.put("url", url.toString());
respMap.put("key", randStr);
//bucket=${bucket}&object=${object}&etag=${etag}&size=${size}&mimeType=${mimeType}&my_var=${x:my_var}
/* String callback = "{\"callbackUrl\":\"" + callbackurl + "\",\"callbackBody\":\"filename=${object}&size=${size}&mimeType=${mimeType}&"
+ "orderid=" + orderid + "&calbackright=" + calbackright + "\",\"callbackBodyType\":\"application/x-www-form-urlencoded\"}";*/
//先传入一个固定值测试
// String callback = "{\"callbackUrl\":\"" + callbackurl + "\",\"callbackBody\":\"filename=${object}&size=${size}&mimeType=${mimeType}&orderid=123\",\"callbackBodyType\":\"application/x-www-form-urlencoded\"}";
//String callback = "{\"callbackUrl\":\""+callbackurl+"\",\"callbackBody\":\"{\'bucket\':${bucket}, \'object\':${object},\'size\':${size},\'mimeType\':${mimeType},\'uid\':${x:uid}}\",\"callbackBodyType\":\"application/json\"}";
String callbackbody = "{\'bucket\':${bucket}, \'object\':${object},\'size\':${size},\'mimeType\':${mimeType},\'uid\':${x:uid},\'biz_type\':${x:biz_type}}";
if("1".equals(biz_type)){//用户头像，banner修改
callbackbody = "{\'bucket\':${bucket}, \'object\':${object},\'size\':${size},\'mimeType\':${mimeType},\'uid\':${x:uid},\'biz_type\':${x:biz_type},\'portrait\':${x:portrait},\'banner\':${x:banner}}";
}else if("2".equals(biz_type)){//投诉建议
callbackbody = "{\'bucket\':${bucket}, \'object\':${object},\'size\':${size},\'mimeType\':${mimeType},\'uid\':${x:uid},\'biz_type\':${x:biz_type},\'path\':${x:path},\'guideid\':${x:guideid}}";
}
String callback = "{\"callbackUrl\":\""+callbackurl+"\",\"callbackBody\":\""+callbackbody+"\",\"callbackBodyType\":\"application/json\"}";
byte[] bytes = Base64.encodeBase64(callback.getBytes("UTF-8"));
respMap.put("callback", new String(bytes));
//respMap.put("callback_str", callback);
JSONObject ja1 = JSONObject.fromObject(respMap);
System.out.println("=====respMap:===== "+ja1.toString());
getResponse().setHeader("Access-Control-Allow-Origin", "*");
getResponse().setHeader("Access-Control-Allow-Methods", "GET, POST");
setJsonString(AppJSON.succReq("请求成功", ja1.toString()));
} catch (Exception e) {
Assert.fail(e.getMessage());
}
return "ajax";
}
三. 回调方法处理业务逻辑
该回调方法是一个servlet，需要在web.xml中配置 访问的路径地址。在servlet中，主要进行业务处理，这里就不在贴出我的业务处理了，大家根据自己的实际需要进行编码。
package com.zd.servlet;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URI;
import java.net.URL;
import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.spec.X509EncodedKeySpec;
import java.text.ParseException;
import java.util.Date;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.sf.json.JSONObject;
import org.apache.commons.lang.StringUtils;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import com.aliyun.oss.common.utils.BinaryUtil;
import com.zd.aliyun.oss.HttpMethod;
import com.zd.aliyun.oss.OSSClient;
import com.zd.aliyun.oss.common.utils.DateUtil;
import com.zd.aliyun.oss.model.GeneratePresignedUrlRequest;
import com.zd.util.Cont;
import com.zd.util.FileUtil;
import com.zd.util.StringUtil;
import com.zd.util.codeBuild.PropertiesUtil; @SuppressWarnings("deprecation")
@WebServlet(asyncSupported = true)
public class OssCallBackService extends HttpServlet {
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
this.doPost(req, resp);
response(req, resp, "input get ", 200);
} @SuppressWarnings({ "finally" })
public String executeGet(String url) {
BufferedReader in = null;
String content = null;
try {
// 定义HttpClient
@SuppressWarnings("resource")
DefaultHttpClient client = new DefaultHttpClient();
// 实例化HTTP方法
HttpGet request = new HttpGet();
request.setURI(new URI(url));
HttpResponse response = client.execute(request); in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
StringBuffer sb = new StringBuffer("");
String line = "";
String NL = System.getProperty("line.separator");
while ((line = in.readLine()) != null) {
sb.append(line + NL);
}
in.close();
content = sb.toString();
} catch (Exception e) {
} finally {
if (in != null) {
try {
in.close();// 最后要关闭BufferedReader
} catch (Exception e) {
e.printStackTrace();
}
}
return content;
}
} public String GetPostBody(InputStream is, int contentLen) {
if (contentLen > 0) {
int readLen = 0;
int readLengthThisTime = 0;
byte[] message = new byte[contentLen];
try {
while (readLen != contentLen) {
readLengthThisTime = is.read(message, readLen, contentLen - readLen);
if (readLengthThisTime == -1) {// Should not happen.
break;
}
readLen += readLengthThisTime;
}
return new String(message);
} catch (IOException e) {
}
}
return "";
} //oss回调请求
protected boolean VerifyOSSCallbackRequest(HttpServletRequest request, String ossCallbackBody) throws NumberFormatException, IOException
{
boolean ret = false;
String autorizationInput = new String(request.getHeader("Authorization"));
String pubKeyInput = request.getHeader("x-oss-pub-key-url");
byte[] authorization = BinaryUtil.fromBase64String(autorizationInput);
byte[] pubKey = BinaryUtil.fromBase64String(pubKeyInput);
String pubKeyAddr = new String(pubKey);
if (!pubKeyAddr.startsWith("http://gosspublic.alicdn.com/") && !pubKeyAddr.startsWith("https://gosspublic.alicdn.com/"))
{
System.out.println("pub key addr must be oss addrss");
return false;
}
String retString = executeGet(pubKeyAddr);
retString = retString.replace("-----BEGIN PUBLIC KEY-----", "");
retString = retString.replace("-----END PUBLIC KEY-----", "");
String queryString = request.getQueryString();
String uri = request.getRequestURI();
String decodeUri = java.net.URLDecoder.decode(uri, "UTF-8");
String authStr = decodeUri;
if (queryString != null && !queryString.equals("")) {
authStr += "?" + queryString;
}
authStr += "\n" + ossCallbackBody;
ret = doCheck(authStr, authorization, retString);
return ret;
} protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//HttpServletRequest
String ossCallbackBody = GetPostBody(request.getInputStream(), Integer.parseInt((request).getHeader("content-length")));
System.out.println("ossCallbackBody == "+ossCallbackBody); boolean ret = VerifyOSSCallbackRequest(request, ossCallbackBody);
System.out.println("verify result:" + ret); // String aaa ="{\"bucket\":\"picture-zoomdu\",\"object\":\"2017072131713.jpg\",\"size\":\"12345\","gid":"86","uid":"121","type":"1"}
JSONObject obj = JSONObject.fromObject(ossCallbackBody);
PropertiesUtil pro = new PropertiesUtil("oss.properties");
String endpoint = pro.readValue("endpoint");
String accessKeyId = pro.readValue("accessKeyId");
String accessKeySecret = pro.readValue("accessKeySecret"); String bucketName = obj.get("bucket").toString();
String bucketkey = obj.get("object").toString(); OSSClient ossClient = new OSSClient(endpoint, accessKeyId, accessKeySecret);
Date expirations = null;
try {
expirations = DateUtil.parseRfc822Date("Wed, 18 Mar 2019 14:20:00 GMT");
} catch (ParseException e) {
e.printStackTrace();
}
GeneratePresignedUrlRequest requestGenerate = new GeneratePresignedUrlRequest(bucketName, bucketkey, HttpMethod.GET);
requestGenerate.setExpiration(expirations); URL signedUrl = ossClient.generatePresignedUrl(requestGenerate);
String path =signedUrl.toString();
if(signedUrl.toString().indexOf("?")>-1){
path = path.substring(0,signedUrl.toString().indexOf("?"));
}
// 图片压缩配置的字符串
path += "?x-oss-process=style/zd_list_image";
String ossurl = "{\"ossurl\":\""+signedUrl.toString()+"\"}";
if (ret){//签名验证通过，业务处理
//客户端 在回调中需要 传入的字段 response(request, response, "{\"Status\":\"OK\"}", HttpServletResponse.SC_OK);
//业务处理..... 此处省略
if(obj.containsKey("uid") && StringUtils.isNotEmpty(obj.get("uid")+"")){
String uid = obj.get("uid").toString();
//biz_type : 1:用户头像、banner ,2:投诉建议图片上传 }
}
else{
response(request, response, "{\"Status\":\"verdify not ok\"}", HttpServletResponse.SC_BAD_REQUEST);
}
} public static boolean doCheck(String content, byte[] sign, String publicKey) {
try {
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
byte[] encodedKey = BinaryUtil.fromBase64String(publicKey);
PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));
java.security.Signature signature = java.security.Signature.getInstance("MD5withRSA");
signature.initVerify(pubKey);
signature.update(content.getBytes());
boolean bverify = signature.verify(sign);
return bverify; } catch (Exception e) {
e.printStackTrace();
} return false;
} private void response(HttpServletRequest request, HttpServletResponse response, String results, int status) throws IOException {
String callbackFunName = request.getParameter("callback");
System.out.println("callbackFunName:"+callbackFunName);
response.addHeader("Content-Length", String.valueOf(results.length()));
if (callbackFunName == null || callbackFunName.equalsIgnoreCase(""))
response.getWriter().println(results);
else
response.getWriter().println(callbackFunName + "( " + results + " )");
response.setStatus(status);
response.flushBuffer();
} }
四.关于oss 上传，并设置回调就介绍到这里，本篇文章没有介绍，oss服务配置，主要是讲技术坑。如有什么问题，请留言联系我，很乐意解决大家的问题。
另外郑重说明，本篇文章是本人原创，如需转载 请标注转载原文地址。