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 normalFieldMap = form.getNormalField();
for (Iterator> iterator = normalFieldMap.entrySet().iterator(); iterator.hasNext();)
{
Entry 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 fileFieldMap = form.getFileField();
for (Iterator> iterator = fileFieldMap.entrySet().iterator(); iterator.hasNext();)
{
Entry 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 normalField = new LinkedHashMap();
/** 文件字段 **/
private Map fileField = new LinkedHashMap();
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 getNormalField()
{
return normalField;
}
public void setNormalField(Map normalField)
{
this.normalField = normalField;
}
public Map getFileField()
{
return fileField;
}
public void setFileField(Map 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

以上就是本文的全部内容，希望本文的内容对大家的学习或者工作能带来一定的帮助！