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

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，同时也希望多多支持！