Java实现表单提交（支持多文件同时上传）

在Android里面或者J2EE后台需要趴别人网站数据，模拟表单提交是一件很常见的事情，但是在Android里面要实现多文件上传，还要夹着普通表单字段上传，这下可能就有点费劲了，今天花时间整理了一个工具类，主要是借助于HttpClient，其实也很简单，看一下代码就非常清楚了

HttpClient工具类：

HttpClientUtil.java

package cn.com.ajava.util;
import java.io.File;
import java.io.Serializable;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

/**
 * HttpClient工具类
 *
 * @author 曾繁添
 * @version 1.0
 */
public class HttpClientUtil
{
 public final static String Method_POST = "POST";
 public final static String Method_GET = "GET";
 /**
 * multipart/form-data类型的表单提交
 *
 * @param form
 *  表单数据
 */
 public static String submitForm(MultipartForm form)
 {
 // 返回字符串
 String responseStr = "";
 // 创建HttpClient实例
 HttpClient httpClient = new DefaultHttpClient();
 try
 {
  // 实例化提交请求
  HttpPost httpPost = new HttpPost(form.getAction());
  // 创建MultipartEntityBuilder
  MultipartEntityBuilder entityBuilder = MultipartEntityBuilder.create();
  // 追加普通表单字段
  Map<String, String> normalFieldMap = form.getNormalField();
  for (Iterator<Entry<String, String>> iterator = normalFieldMap.entrySet().iterator(); iterator.hasNext();)
  {
  Entry<String, String> entity = iterator.next();
  entityBuilder.addPart(entity.getKey(), new StringBody(entity.getValue(), ContentType.create("text/plain", Consts.UTF_8)));
  }
  // 追加文件字段
  Map<String, File> fileFieldMap = form.getFileField();
  for (Iterator<Entry<String, File>> iterator = fileFieldMap.entrySet().iterator(); iterator.hasNext();)
  {
  Entry<String, File> entity = iterator.next();
  entityBuilder.addPart(entity.getKey(), new FileBody(entity.getValue()));
  }
  // 设置请求实体
  httpPost.setEntity(entityBuilder.build());
  // 发送请求
  HttpResponse response = httpClient.execute(httpPost);
  int statusCode = response.getStatusLine().getStatusCode();
  // 取得响应数据
  HttpEntity resEntity = response.getEntity();
  if (200 == statusCode)
  {
  if (resEntity != null)
  {
   responseStr = EntityUtils.toString(resEntity);
  }
  }
 } catch (Exception e)
 {
  System.out.println("提交表单失败，原因：" + e.getMessage());
 } finally
 {
  httpClient.getConnectionManager().shutdown();
 }
 return responseStr;
 }
 /** 表单字段Bean */
 public class MultipartForm implements Serializable
 {
 /** 序列号 */
 private static final long serialVersionUID = -2138044819190537198L;
 /** 提交URL **/
 private String action = "";
 /** 提交方式：POST/GET **/
 private String method = "POST";
 /** 普通表单字段 **/
 private Map<String, String> normalField = new LinkedHashMap<String, String>();
 /** 文件字段 **/
 private Map<String, File> fileField = new LinkedHashMap<String, File>();
 public String getAction()
 {
  return action;
 }
 public void setAction(String action)
 {
  this.action = action;
 }
 public String getMethod()
 {
  return method;
 }
 public void setMethod(String method)
 {
  this.method = method;
 }
 public Map<String, String> getNormalField()
 {
  return normalField;
 }
 public void setNormalField(Map<String, String> normalField)
 {
  this.normalField = normalField;
 }
 public Map<String, File> getFileField()
 {
  return fileField;
 }
 public void setFileField(Map<String, File> fileField)
 {
  this.fileField = fileField;
 }
 public void addFileField(String key, File value)
 {
  fileField.put(key, value);
 }
 public void addNormalField(String key, String value)
 {
  normalField.put(key, value);
 }
 }
}

服务器端实现文件上传、并且读取参数方法：（借助于Apache的fileupload组件实现，实现了获取表单action后面直接拼接参数、表单普通项目、文件项目三种字段获取方法）

后台我就直接写了一个Servlet，具体代码如下：

ServletUploadFile.java

package cn.com.ajava.servlet;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
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;
/**
 * 文件上传Servlet
 * @author 曾繁添
 */
public class ServletUploadFile extends HttpServlet
{
 private static final long serialVersionUID = 1L;
 // 限制文件的上传大小 1G
 private int maxPostSize = 1000 * 1024 * 10;
 public ServletUploadFile()
 {
 super();
 }
 @Override
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException,
 IOException
 {
 doPost(request, response);
 }
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,
 IOException
 {
 PrintWriter out = response.getWriter();
 String contextPath = request.getSession().getServletContext().getRealPath("/");
 String webDir = "uploadfile" + File.separator + "images" + File.separator;
 String systemPath = request.getContextPath();
 String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort()+ systemPath + "/";
 request.setCharacterEncoding("UTF-8");
 response.setContentType("text/html;charset=UTF-8");
 try
 {
 DiskFileItemFactory factory = new DiskFileItemFactory();
 factory.setSizeThreshold(1024 * 4); // 设置写入大小
 ServletFileUpload upload = new ServletFileUpload(factory);
 upload.setSizeMax(maxPostSize); // 设置文件上传最大大小
 System.out.println(request.getContentType());
 //获取action后面拼接的参数(如：http://www.baidu.com?q=android)
 Enumeration enumList = request.getParameterNames();
 while(enumList.hasMoreElements()){
 String key = (String)enumList.nextElement();
 String value = request.getParameter(key);
 System.out.println(key+"="+value);
 }
 //获取提交表单项目
 List listItems = upload.parseRequest(request);
 Iterator iterator = listItems.iterator();
 while (iterator.hasNext())
 {
 FileItem item = (FileItem) iterator.next();
 //非普通表单项目
 if (!item.isFormField())
 {
  //获取扩展名
  String ext = item.getName().substring(item.getName().lastIndexOf("."), item.getName().length());
  String fileName = System.currentTimeMillis() + ext;
  File dirFile = new File(contextPath + webDir + fileName);
  if (!dirFile.exists())
  {
  dirFile.getParentFile().mkdirs();
  }
  item.write(dirFile);
  System.out.println("fileName：" + item.getName() + "=====" + item.getFieldName() + " size： "+ item.getSize());
  System.out.println("文件已保存到： " + contextPath + webDir + fileName);
  //响应客户端请求
  out.print(basePath + webDir.replace("\\", "/") + fileName);
  out.flush();
 }else{
  //普通表单项目
  System.out.println("表单普通项目："+item.getFieldName()+"=" + item.getString("UTF-8"));// 显示表单内容。item.getString("UTF-8")可以保证中文内容不乱码
 }
 }
 } catch (Exception e)
 {
 e.printStackTrace();
 } finally
 {
 out.close();
 }
 }
}

工具类、服务器端代码上面都贴出来了，具体怎么调用应该就不需要说了吧？封装的已经够清晰明了了

调用示例DEMO：

//创建HttpClientUtil实例
HttpClientUtil httpClient = new HttpClientUtil();
MultipartForm form = httpClient.new MultipartForm();
//设置form属性、参数
form.setAction("http://192.168.1.7:8080/UploadFileDemo/cn/com/ajava/servlet/ServletUploadFile");
File photoFile = new File(sddCardPath+"//data//me.jpg");
form.addFileField("photo", photoFile);
form.addNormalField("name", "曾繁添");
form.addNormalField("tel", "15122946685");
//提交表单
HttpClientUtil.submitForm(form);

最后说明一下jar问题：

要是android里面应用的话，需要注意一下额外引入httpmime-4.3.1.jar（我当时下的这个是最高版本了），至于fileUpload的jar，直接去apache官网下载吧

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