采用multipart/form-data方式 调用上传图片接口

需求： 在手机客户端调用服务器端接口 把手机中的图片上传到 接口提供的服务器上。

例如 新浪微博中的 发表附带图片的微博。 

注：这里最好不要用socker编程来实现，由于当图片过大的时候，图片被解析成二进制(或者字节   数组)经过socker流传过来的时候比较慢，当网络慢的时候每每会由于超时抛异常致使不能调用接口 成功。  

其实能够在客户端模拟表单提交同样，把图片附件上传到接口提供的服务器上。

 新浪和腾讯的微博都是这样实现的，具体能够参考： 

新浪微博接口：  http://open.weibo.com/wiki/Statuses/upload  

腾讯微博接口：  http://wiki.open.t.qq.com/index.php/API%E6%96%87%E6%A1%A3/%E5%BE%AE%E5%8D%9A%E6%8E%A5%E5%8F%A3/%E5%8F%91%E8%A1%A8%E4%B8%80%E6%9D%A1%E5%B8%A6%E5%9B%BE%E7%89%87%E7%9A%84%E5%BE%AE%E5%8D%9A

个人实现代码以下（测试经过）：


客户端调用代码：

package com.common.myTest;

import java.io.File;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.multipart.FilePart;
import org.apache.commons.httpclient.methods.multipart.MultipartRequestEntity;
import org.apache.commons.httpclient.methods.multipart.Part;
public class Hclient {
 public static void main(String args[]) {
  String targetURL = null; //-- 指定URL
  File targetFile = null; //-- 指定上传文件
  targetFile = new File("D:\\image1\\超大图片.jpg");
  targetURL = "http://localhost:8080/servlet/HServlets"; // servleturl
  PostMethod filePost = new PostMethod(targetURL);
  try {
   // 经过如下方法能够模拟页面参数提交
   Part[] parts = { new FilePart(targetFile.getName(), targetFile) };
   filePost.setRequestEntity(new MultipartRequestEntity(parts,
     filePost.getParams()));
   HttpClient client = new HttpClient();
   client.getHttpConnectionManager().getParams().setConnectionTimeout(
     5000);
   int status = client.executeMethod(filePost);
   if (status == HttpStatus.SC_OK) {
    System.out.println("上传成功");
    // 上传成功
   } else {
    System.out.println("上传失败");
    // 上传失败
   }
  } catch (Exception ex) {
   ex.printStackTrace();
  } finally {
   filePost.releaseConnection();
  }
 }
}

服务器端代码：

package com.common.myTest;

import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class HServlets extends HttpServlet {
    private Log log = LogFactory.getLog(HServlets.class);
 private static final long serialVersionUID = 1L;
 private String uploadPath; // 上传文件的目录
 private String tempPath; // 临时文件目录
 File tempPathFile;

 public void init(ServletConfig config) throws ServletException {
  super.init(config);
  uploadPath = config.getServletContext().getInitParameter("imageStorePath");
  tempPath = config.getServletContext().getInitParameter("images_120");
  
  File uploadFile = new File(uploadPath);
  if (!uploadFile.exists()) {
   uploadFile.mkdirs();
  }
  File tempPathFile = new File(tempPath);
  if (!tempPathFile.exists()) {
   tempPathFile.mkdirs();
  }
 }

 @SuppressWarnings("unchecked")
 public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
  try {
      log.info("进入上传图片的servlt");

   DiskFileItemFactory factory = new DiskFileItemFactory();
   factory.setSizeThreshold(4096); // 设置缓冲区大小，这里是4kb
   factory.setRepository(tempPathFile);// 设置缓冲区目录

   ServletFileUpload upload = new ServletFileUpload(factory);
   upload.setSizeMax(4194304); // 设置最大文件尺寸，这里是4MB
   List<FileItem> items = upload.parseRequest(request);// 获得全部的文件
   Iterator<FileItem> i = items.iterator();
   while (i.hasNext()) {
    FileItem fi = (FileItem) i.next();
    String fileName = fi.getName();
    log.info("上传图片的名字："+fileName);
    if (fileName != null) {
     File fullFile = new File(fi.getName());
     File savedFile = new File(uploadPath, fullFile.getName());
     fi.write(savedFile);
    }
   }
   log.info("上传成功!");
  } catch (Exception e) {
   log.info(e.getMessage());
   // 能够跳转出错页面
   e.printStackTrace();
  }
 }


}