阿里云OSS图片上传（java web直传）

最近使用到阿里云的OSS做图片上传，特别记录操作流程。

本demo是最原汁原味的oss图片上传，基本没有经过加工，最容易读懂和理解。

一创建bucket和配置跨域

创建bucket步骤:

略。（为了访问方便，建议读写权限设置为公共读）

配置跨域：

权限管理>>跨域设置，如果不设置话的，上传文件时，浏览器会提示禁止跨域403

二服务端签名（java版）

（1）maven导包

<dependency>
            <groupId>com.aliyun.oss</groupId>
            <artifactId>aliyun-sdk-oss</artifactId>
            <version>3.11.1</version>
        </dependency>
        
        <dependency>  
            <groupId>net.sf.json-lib</groupId>  
            <artifactId>json-lib</artifactId>  
            <version>2.2.3</version>  
            <classifier>jdk15</classifier><!-- 指定jdk版本 -->  
        </dependency>

（2）填写accessId,accessKey,endPoint(demo写的杭州),bucket。

package com.durian.amanager.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.Map;

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 org.apache.commons.lang3.StringUtils;

import com.aliyun.oss.OSS;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.common.utils.BinaryUtil;
import com.aliyun.oss.model.MatchMode;
import com.aliyun.oss.model.PolicyConditions;

import net.sf.json.JSONObject;

//获取阿里云oss policy
@WebServlet(urlPatterns = "/aliyunoss_getpolicy")
public class AliyunOssServlet extends HttpServlet {

	/**
	 * 
	 */
	private static final long serialVersionUID = 4108505220500631L;

	protected void service(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		
		String dir=request.getParameter("dir");// 用户上传文件时指定的前缀。
		if(StringUtils.isEmpty(dir)){
			dir="";
		}else{
			dir=dir+"/";
		}

		 String accessId = "<yourAccessKeyId>"; // 请填写您的AccessKeyId。
		 String accessKey = "<yourAccessKeySecret>"; // 请填写您的AccessKeySecret。
		 String endpoint = "oss-cn-hangzhou.aliyuncs.com"; // 请填写您的 endpoint。
		 String bucket = "bucket-name"; // 请填写您的 bucketname 。

		
		String host = "https://" + bucket + "." + endpoint; // host的格式为
															// bucketname.endpoint
		// callbackUrl为 上传回调服务器的URL，请将下面的IP和Port配置为您自己的真实信息。
		String callbackUrl = "";
		//String format = new SimpleDateFormat("yyyy-MM-dd").format(new Date());

		// 创建OSSClient实例。
		OSS ossClient = new OSSClientBuilder().build(endpoint, accessId, accessKey);
		try {
			long expireTime = 300;
			long expireEndTime = System.currentTimeMillis() + expireTime * 1000;
			Date expiration = new Date(expireEndTime);
			// PostObject请求最大可支持的文件大小为5
			// GB，即CONTENT_LENGTH_RANGE为5*1024*1024*1024。
			PolicyConditions policyConds = new PolicyConditions();
			policyConds.addConditionItem(PolicyConditions.COND_CONTENT_LENGTH_RANGE, 0, 1048576000);
			policyConds.addConditionItem(MatchMode.StartWith, PolicyConditions.COND_KEY, dir);

			String postPolicy = ossClient.generatePostPolicy(expiration, policyConds);
			byte[] binaryData = postPolicy.getBytes("utf-8");
			String encodedPolicy = BinaryUtil.toBase64String(binaryData);
			String postSignature = ossClient.calculatePostSignature(postPolicy);

			Map<String, String> respMap = new LinkedHashMap<String, String>();
			respMap.put("accessid", accessId);
			respMap.put("policy", encodedPolicy);
			respMap.put("signature", postSignature);
			respMap.put("dir", dir);
			respMap.put("host", host);
			respMap.put("expire", String.valueOf(expireEndTime / 1000));
			// respMap.put("expire", formatISO8601Date(expiration));

			JSONObject jasonCallback = new JSONObject();
			jasonCallback.put("callbackUrl", callbackUrl);
			jasonCallback.put("callbackBody",
					"filename=${object}&size=${size}&mimeType=${mimeType}&height=${imageInfo.height}&width=${imageInfo.width}");
			jasonCallback.put("callbackBodyType", "application/x-www-form-urlencoded");
			String base64CallbackBody = BinaryUtil.toBase64String(jasonCallback.toString().getBytes());
			respMap.put("callback", base64CallbackBody);

			JSONObject ja1 = JSONObject.fromObject(respMap);
			// System.out.println(ja1.toString());
			response.setHeader("Access-Control-Allow-Origin", "*");
			response.setHeader("Access-Control-Allow-Methods", "GET, POST");
			response(request, response, ja1.toString());

		} catch (Exception e) {
			// Assert.fail(e.getMessage());
			System.out.println(e.getMessage());
		} finally {
			ossClient.shutdown();
		}
	}

	/**
	 * 回传参数
	 * 
	 * @param resp
	 *            回传类
	 * @param data
	 *            回传数据
	 * @throws IOException
	 */
	public static void response(HttpServletRequest request, HttpServletResponse response, String data) {
		try {
			response.setCharacterEncoding("utf-8");
			response.setContentType("text/html");
			PrintWriter out = response.getWriter();
			out.print(data);
			out.flush();
			out.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}