檔案上傳分為兩個部分：
(1)伺服器端：需要使用FileUpload+common.io實現檔案的上傳；
(2)用戶端：需要類比檔案上傳的HTTP要求標頭；
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); //設定上傳檔案的最大容量try{List<FileItem>items = upload.parseRequest(request); //取得表單全部資料for(FileItem item:items){if(!item.isFormField()){//如果是上傳的檔案 String name = "D:\\"+item.getName().substring(item.getName().lastIndexOf('\\')+1); String filename = name; System.out.println(filename); File f = new File(filename);//儲存到D盤 item.write(f); System.out.println("上傳成功");}}}catch(Exception e){e.printStackTrace();}}}
瀏覽器端代碼：
<!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">檔案上傳：<input type="file" name="filename"/><br/><input type="submit" value="get提交"></form></body></html>二、用戶端前期準備及核心代碼
1.前期準備
由於用戶端需要類比HTTP請求，因此我們可以先來看下檔案上傳的HTTP請求：
| 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 //此處為分隔字元，用來分隔多個檔案和參數 Accept-Encoding: gzip, deflate Host: localhost:8080 Content-Length: 14610 Connection: Keep-Alive Cache-Control: no-cache -----------------------------7dc372520758 |
由此看出，這個HTTP請求比較難以類比，此處封裝了一個輔助類，是黎活明老師實現的，我們可以直接使用：
HttpRequestUtil.uploadFile(String path, Map<String, String> params, FormFile file)
path：URL
params：一般的參數
file：檔案
HttpRequestUtil.uploadFiles(String path, Map<String, String> params, FormFile[] files)
path：URL
params：一般的參數
files：多個檔案
FormFile.java
package com.xiazdong.netword.http.util;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.InputStream;/** * 上傳檔案 */public class FormFile {/* 上傳檔案的資料 */private byte[] data;private InputStream inStream;private File file;/* 檔案名稱 */private String filname;/* 請求參數名稱*/private String parameterName;/* 內容類型 */private String contentType = "application/octet-stream";/** * 此函數用來傳輸小檔案 * @param filname * @param data * @param parameterName HTML的控制項參數名稱 * @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;}/** * 此函數用來傳輸大檔案 * @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;/* * 此類用來發送HTTP請求 * */public class HttpRequestUtil {/** * 直接通過HTTP協議提交資料到伺服器,實現如下面表單提交功能: * <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 上傳路徑(註：避免使用localhost或127.0.0.1這樣的路徑測試，因為它會指向手機模擬器，你可以使用http://www.itcast.cn或http://192.168.1.10:8080這樣的路徑測試) * @param params 請求參數 key為參數名,value為參數值 * @param file 上傳檔案 */public static boolean uploadFiles(String path, Map<String, String> params, FormFile[] files) throws Exception{ final String BOUNDARY = "---------------------------7da2137580612"; //資料分隔線 final String endline = "--" + BOUNDARY + "--\r\n";//資料結束標誌 int fileDataLength = 0; if(files!=null&&files.length!=0){ for(FormFile uploadFile : files){//得到檔案類型資料的總長度 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()) {//構造文本型別參數的實體資料 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"); } } //計算傳輸給伺服器的實體資料總長度 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要求標頭的發送 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()); //寫完HTTP要求標頭後根據HTTP協議再寫一個斷行符號換行 outStream.write("\r\n".getBytes()); //把所有文本類型的實體資料發送出來 outStream.write(textEntity.toString().getBytes()); //把所有檔案類型的實體資料發送出來 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()); } } //下面發送資料結束標誌，表示資料已經結束 outStream.write(endline.getBytes()); BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream())); if(reader.readLine().indexOf("200")==-1){//讀取web伺服器返回的資料，判斷請求碼是否為200，如果不是200，代表請求失敗 return false; } outStream.flush(); outStream.close(); reader.close(); socket.close(); return true;}/** * 提交資料到伺服器 * @param path 上傳路徑(註：避免使用localhost或127.0.0.1這樣的路徑測試，因為它會指向手機模擬器，你可以使用http://www.itcast.cn或http://192.168.1.10:8080這樣的路徑測試) * @param params 請求參數 key為參數名,value為參數值 * @param file 上傳檔案 */public static boolean uploadFile(String path, Map<String, String> params, FormFile file) throws Exception{ return uploadFiles(path, params, new FormFile[]{file});}/** * 將輸入資料流轉為位元組數組 * @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();}/** * 將輸入資料流轉為字串 * @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.核心代碼
FormFile formFile = new FormFile(file.getName(), file, "document", "text/plain");//"document"為控制項的名稱,"text/plain"為檔案的mimetypeboolean isSuccess = HttpRequestUtil.uploadFile("http://192.168.0.103:8080/Server/FileServlet", null, formFile);
三、用戶端代碼
<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(){@Overridepublic 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);//獲得SDCARD的檔案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, "檔案上傳成功", Toast.LENGTH_SHORT).show();}else{Toast.makeText(MainActivity.this, "檔案上傳失敗", Toast.LENGTH_SHORT).show();}} catch (Exception e) {e.printStackTrace();}}else{Toast.makeText(MainActivity.this, "檔案不存在", 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);}}
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