Java implements form submission (multiple files can be uploaded simultaneously)

In Android or J2EE background need to lie prone others site data, simulate the form submission is a very common thing, but in Android to achieve multiple file upload, even with ordinary form fields, this may be a bit difficult, today take time to organize a utility class, mainly by HttpClient, actually very simple, also see 1 under the code is very clear

HttpClient tool class:

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 Utility class 
 * 
 * @author  Zeng Fantian 
 * @version 1.0
 */
public class HttpClientUtil
{
 public final static String Method_POST = "POST";
 public final static String Method_GET = "GET";
 /**
 * multipart/form-data Type of form submission 
 * 
 * @param form
 *   The form data 
 */
 public static String submitForm(MultipartForm form)
 {
 //  Return string 
 String responseStr = "";
 //  create HttpClient The instance 
 HttpClient httpClient = new DefaultHttpClient();
 try
 {
  //  Instantiate the submit request 
  HttpPost httpPost = new HttpPost(form.getAction());
  //  create MultipartEntityBuilder
  MultipartEntityBuilder entityBuilder = MultipartEntityBuilder.create();
  //  Appends normal form fields 
  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)));
  }
  //  Append file field 
  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()));
  }
  //  Set request entity 
  httpPost.setEntity(entityBuilder.build());
  //  Send the request 
  HttpResponse response = httpClient.execute(httpPost);
  int statusCode = response.getStatusLine().getStatusCode();
  //  Get response data 
  HttpEntity resEntity = response.getEntity();
  if (200 == statusCode)
  {
  if (resEntity != null)
  {
   responseStr = EntityUtils.toString(resEntity);
  }
  }
 } catch (Exception e)
 {
  System.out.println(" The submission of the form failed. Reasons: " + e.getMessage());
 } finally
 {
  httpClient.getConnectionManager().shutdown();
 }
 return responseStr;
 }
 /**  Form fields Bean */
 public class MultipartForm implements Serializable
 {
 /**  The serial number  */
 private static final long serialVersionUID = -2138044819190537198L;
 /**  submit URL **/
 private String action = "";
 /**  Submission method: POST/GET **/
 private String method = "POST";
 /**  Normal form field  **/
 private Map<String, String> normalField = new LinkedHashMap<String, String>();
 /**  The file field  **/
 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);
 }
 }
}

Server-side file upload and parameter reading method :(with the help of Apache's fileupload component implementation, it realizes the three methods of obtaining the fields directly after the form action: splicing parameters, form common items, and file items)

In the background, I directly wrote an Servlet, the specific code is as follows:

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;
/**
 *  File upload Servlet
 * @author  Zeng Fantian 
 */
public class ServletUploadFile extends HttpServlet
{
 private static final long serialVersionUID = 1L;
 //  Limit file upload size  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); //  Set write size 
 ServletFileUpload upload = new ServletFileUpload(factory);
 upload.setSizeMax(maxPostSize); //  Set the maximum file upload size 
 System.out.println(request.getContentType());
 // To obtain action After the splicing parameter ( Such as: 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);
 }
 // Gets the submit form project 
 List listItems = upload.parseRequest(request);
 Iterator iterator = listItems.iterator();
 while (iterator.hasNext())
 {
 FileItem item = (FileItem) iterator.next();
 // Not a normal form project 
 if (!item.isFormField())
 {
  // Get the extension 
  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(" File saved to:  " + contextPath + webDir + fileName);
  // Respond to client requests 
  out.print(basePath + webDir.replace("\\", "/") + fileName);
  out.flush();
 }else{
  // Normal form items 
  System.out.println(" Form general items: "+item.getFieldName()+"=" + item.getString("UTF-8"));//  Display the form content. item.getString("UTF-8") You can ensure that the Chinese content is not garbled 
 }
 }
 } catch (Exception e)
 {
 e.printStackTrace();
 } finally
 {
 out.close();
 }
 }
}

Tool class, server code are posted above, the specific how to call should not need to say? The package is clear enough

Call example DEMO:

// create HttpClientUtil The instance 
HttpClientUtil httpClient = new HttpClientUtil();
MultipartForm form = httpClient.new MultipartForm();
// Set up the form Properties, parameters 
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", " Zeng Fantian ");
form.addNormalField("tel", "15122946685");
// Submit the form 
HttpClientUtil.submitForm(form);

Finally, 1. The problem of jar:

If you are using android, please note that httpmime-4.3.1.jar (the version I used was the highest version at that time) will be introduced. As for jar of fileUpload, please go to the apache website to download it