文件上传分为两个部分：
(1)服务器端：需要使用FileUpload+common.io实现文件的上传；
(2)客户端：需要模拟文件上传的HTTP请求头；
一、服务器端代码
FileServlet.java
package org.xiazdong.servlet;
import java.io.File;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
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;
@WebServlet("/FileServlet")
public class FileServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setFileSizeMax(1024*1024); //设置上传文件的最大容量
try{
List<FileItem>items = upload.parseRequest(request); //取得表单全部数据
for(FileItem item:items){
if(!item.isFormField()){ //如果是上传的文件
String name = "D:\\"+item.getName().substring(item.getName().lastIndexOf('\\')+1);
String filename = name;
System.out.println(filename);
File f = new File(filename); //保存到D盘
item.write(f);
System.out.println("上传成功");
}
}
}
catch(Exception e){
e.printStackTrace();
}
}
}
浏览器端代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Server Title</title> </head> <body> <form action="/Server/FileServlet" method="post" enctype="multipart/form-data"> 文件上传：<input type="file" name="filename"/><br/> <input type="submit" value="get提交"> </form> </body> </html>
二、客户端前期准备及核心代码
1.前期准备
由于客户端需要模拟HTTP请求，因此我们可以先来看下文件上传的HTTP请求：
| POST /Server/FileServlet HTTP/1.1 Accept: */* Referer: http://localhost:8080/Server/2.html Accept-Language: zh-CN User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0E; .NET4.0C; InfoPath.3) Content-Type: multipart/form-data; boundary=---------------------------7dc372520758 //此处为分隔符，用来分隔多个文件和参数 Accept-Encoding: gzip, deflate Host: localhost:8080 Content-Length: 14610 Connection: Keep-Alive Cache-Control: no-cache -----------------------------7dc372520758 Content-Disposition: form-data; name="filename"; filename="D:\lv6.GIF" Content-Type: image/gif 文件内容 -----------------------------7dc372520758-- //结束时需要多加两个-- |
由此看出，这个HTTP请求比较难以模拟，此处封装了一个辅助类，是黎活明老师实现的，我们可以直接使用：
HttpRequestUtil.uploadFile(String path, Map<String, String> params, FormFile file)
path：URL
params：一般的参数
file：文件
HttpRequestUtil.uploadFiles(String path, Map<String, String> params, FormFile[] files)
path：URL
params：一般的参数
files：多个文件
FormFile.java
package com.xiazdong.netword.http.util;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
/**
* 上传文件
*/
public class FormFile {
/* 上传文件的数据 */
private byte[] data;
private InputStream inStream;
private File file;
/* 文件名称 */
private String filname;
/* 请求参数名称*/
private String parameterName;
/* 内容类型 */
private String contentType = "application/octet-stream";
/**
* 此函数用来传输小文件
* @param filname
* @param data
* @param parameterName HTML的控件参数名称
* @param contentType
*/
public FormFile(String filname, byte[] data, String parameterName, String contentType) {
this.data = data;
this.filname = filname;
this.parameterName = parameterName;
if(contentType!=null) this.contentType = contentType;
}
/**
* 此函数用来传输大文件
* @param filname
* @param file
* @param parameterName
* @param contentType
*/
public FormFile(String filname, File file, String parameterName, String contentType) {
this.filname = filname;
this.parameterName = parameterName;
this.file = file;
try {
this.inStream = new FileInputStream(file);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
if(contentType!=null) this.contentType = contentType;
}
public File getFile() {
return file;
}
public InputStream getInStream() {
return inStream;
}
public byte[] getData() {
return data;
}
public String getFilname() {
return filname;
}
public void setFilname(String filname) {
this.filname = filname;
}
public String getParameterName() {
return parameterName;
}
public void setParameterName(String parameterName) {
this.parameterName = parameterName;
}
public String getContentType() {
return contentType;
}
public void setContentType(String contentType) {
this.contentType = contentType;
}
}
HttpRequestUtil.java
package com.xiazdong.netword.http.util;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.InetAddress;
import java.net.Socket;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
/*
* 此类用来发送HTTP请求
* */
public class HttpRequestUtil {
/**
* 直接通过HTTP协议提交数据到服务器,实现如下面表单提交功能:
* <FORM METHOD=POST ACTION="http://192.168.0.200:8080/ssi/fileload/test.do" enctype="multipart/form-data">
<INPUT TYPE="text" NAME="name">
<INPUT TYPE="text" NAME="id">
<input type="file" name="imagefile"/>
<input type="file" name="zip"/>
</FORM>
* @param path 上传路径(注：避免使用localhost或127.0.0.1这样的路径测试，因为它会指向手机模拟器，你可以使用http://www.itcast.cn或http://192.168.1.10:8080这样的路径测试)
* @param params 请求参数 key为参数名,value为参数值
* @param file 上传文件
*/
public static boolean uploadFiles(String path, Map<String, String> params, FormFile[] files) throws Exception{
final String BOUNDARY = "---------------------------7da2137580612"; //数据分隔线
final String endline = "--" + BOUNDARY + "--\r\n";//数据结束标志
int fileDataLength = 0;
if(files!=null&&files.length!=0){
for(FormFile uploadFile : files){//得到文件类型数据的总长度
StringBuilder fileExplain = new StringBuilder();
fileExplain.append("--");
fileExplain.append(BOUNDARY);
fileExplain.append("\r\n");
fileExplain.append("Content-Disposition: form-data;name=\""+ uploadFile.getParameterName()+"\";filename=\""+ uploadFile.getFilname() + "\"\r\n");
fileExplain.append("Content-Type: "+ uploadFile.getContentType()+"\r\n\r\n");
fileExplain.append("\r\n");
fileDataLength += fileExplain.length();
if(uploadFile.getInStream()!=null){
fileDataLength += uploadFile.getFile().length();
}else{
fileDataLength += uploadFile.getData().length;
}
}
}
StringBuilder textEntity = new StringBuilder();
if(params!=null&&!params.isEmpty()){
for (Map.Entry<String, String> entry : params.entrySet()) {//构造文本类型参数的实体数据
textEntity.append("--");
textEntity.append(BOUNDARY);
textEntity.append("\r\n");
textEntity.append("Content-Disposition: form-data; name=\""+ entry.getKey() + "\"\r\n\r\n");
textEntity.append(entry.getValue());
textEntity.append("\r\n");
}
}
//计算传输给服务器的实体数据总长度
int dataLength = textEntity.toString().getBytes().length + fileDataLength + endline.getBytes().length;
URL url = new URL(path);
int port = url.getPort()==-1 ? 80 : url.getPort();
Socket socket = new Socket(InetAddress.getByName(url.getHost()), port);
OutputStream outStream = socket.getOutputStream();
//下面完成HTTP请求头的发送
String requestmethod = "POST "+ url.getPath()+" HTTP/1.1\r\n";
outStream.write(requestmethod.getBytes());
String accept = "Accept: image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*\r\n";
outStream.write(accept.getBytes());
String language = "Accept-Language: zh-CN\r\n";
outStream.write(language.getBytes());
String contenttype = "Content-Type: multipart/form-data; boundary="+ BOUNDARY+ "\r\n";
outStream.write(contenttype.getBytes());
String contentlength = "Content-Length: "+ dataLength + "\r\n";
outStream.write(contentlength.getBytes());
String alive = "Connection: Keep-Alive\r\n";
outStream.write(alive.getBytes());
String host = "Host: "+ url.getHost() +":"+ port +"\r\n";
outStream.write(host.getBytes());
//写完HTTP请求头后根据HTTP协议再写一个回车换行
outStream.write("\r\n".getBytes());
//把所有文本类型的实体数据发送出来
outStream.write(textEntity.toString().getBytes());
//把所有文件类型的实体数据发送出来
if(files!=null&&files.length!=0){
for(FormFile uploadFile : files){
StringBuilder fileEntity = new StringBuilder();
fileEntity.append("--");
fileEntity.append(BOUNDARY);
fileEntity.append("\r\n");
fileEntity.append("Content-Disposition: form-data;name=\""+ uploadFile.getParameterName()+"\";filename=\""+ uploadFile.getFilname() + "\"\r\n");
fileEntity.append("Content-Type: "+ uploadFile.getContentType()+"\r\n\r\n");
outStream.write(fileEntity.toString().getBytes());
if(uploadFile.getInStream()!=null){
byte[] buffer = new byte[1024];
int len = 0;
while((len = uploadFile.getInStream().read(buffer, 0, 1024))!=-1){
outStream.write(buffer, 0, len);
}
uploadFile.getInStream().close();
}else{
outStream.write(uploadFile.getData(), 0, uploadFile.getData().length);
}
outStream.write("\r\n".getBytes());
}
}
//下面发送数据结束标志，表示数据已经结束
outStream.write(endline.getBytes());
BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
if(reader.readLine().indexOf("200")==-1){//读取web服务器返回的数据，判断请求码是否为200，如果不是200，代表请求失败
return false;
}
outStream.flush();
outStream.close();
reader.close();
socket.close();
return true;
}
/**
* 提交数据到服务器
* @param path 上传路径(注：避免使用localhost或127.0.0.1这样的路径测试，因为它会指向手机模拟器，你可以使用http://www.itcast.cn或http://192.168.1.10:8080这样的路径测试)
* @param params 请求参数 key为参数名,value为参数值
* @param file 上传文件
*/
public static boolean uploadFile(String path, Map<String, String> params, FormFile file) throws Exception{
return uploadFiles(path, params, new FormFile[]{file});
}
/**
* 将输入流转为字节数组
* @param inStream
* @return
* @throws Exception
*/
public static byte[] read2Byte(InputStream inStream)throws Exception{
ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while( (len = inStream.read(buffer)) !=-1 ){
outSteam.write(buffer, 0, len);
}
outSteam.close();
inStream.close();
return outSteam.toByteArray();
}
/**
* 将输入流转为字符串
* @param inStream
* @return
* @throws Exception
*/
public static String read2String(InputStream inStream)throws Exception{
ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while( (len = inStream.read(buffer)) !=-1 ){
outSteam.write(buffer, 0, len);
}
outSteam.close();
inStream.close();
return new String(outSteam.toByteArray(),"UTF-8");
}
}
2.核心代码
FormFile formFile = new FormFile(file.getName(), file, "document", "text/plain");//"document"为控件的名称,"text/plain"为文件的mimetype
boolean isSuccess = HttpRequestUtil.uploadFile("http://192.168.0.103:8080/Server/FileServlet", null, formFile);三、客户端代码
AndroidManifest.xml
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/> <uses-permission android:name="android.permission.INTERNET"/>
MainActivity.java
package org.xiazdong.network.fileupload;
import java.io.File;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import com.xiazdong.netword.http.util.FormFile;
import com.xiazdong.netword.http.util.HttpRequestUtil;
public class MainActivity extends Activity {
private EditText fileName;
private Button button;
private OnClickListener listener = new OnClickListener(){
@Override
public void onClick(View v) {
String fname = fileName.getText().toString();
if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)||Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED_READ_ONLY)){
File file = new File(Environment.getExternalStorageDirectory(),fname); //获得SDCARD的文件
if(file.exists()){
FormFile formFile = new FormFile(file.getName(), file, "document", "text/plain");
try {
boolean isSuccess = HttpRequestUtil.uploadFile("http://192.168.0.103:8080/Server/FileServlet", null, formFile);
if(isSuccess){
Toast.makeText(MainActivity.this, "文件上传成功", Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(MainActivity.this, "文件上传失败", Toast.LENGTH_SHORT).show();
}
} catch (Exception e) {
e.printStackTrace();
}
}
else{
Toast.makeText(MainActivity.this, "文件不存在", Toast.LENGTH_SHORT).show();
}
}
else{
Toast.makeText(MainActivity.this, "SDCARD不存在", Toast.LENGTH_SHORT).show();
}
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
fileName = (EditText)this.findViewById(R.id.filename);
button = (Button)this.findViewById(R.id.button);
button.setOnClickListener(listener);
}
}