与文件下载相比,文件上传的场合不是很多,通常用于上传用户头像、朋友圈发布图片/视频动态等等,而且上传文件需要服务器配合,所以容易被app开发者忽略。就上传的形式来说,app一般采用http上传文件,很少用ftp上传文件。
很可惜Android没有提供专门的文件上传工具类,所以我们要自己写代码实现上传功能了。其实也不难,一样是按照普通网络访问的POST流程,只是要采用“multipart/form-data”方式来分段传输。另外文件上传需要运用打开文件的对话框,文件对话框的介绍参见《Android开发笔记(二十三)文件对话框FileDialog》。 下面是HttpURLConnection上传文件的工具类代码:
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class UploadUtil {
private static final String TAG = "UploadUtil";
public static String upload(String uploadUrl, String uploadFile) {
String fileName = "";
int pos = uploadFile.lastIndexOf("/");
if (pos >= 0) {
fileName = uploadFile.substring(pos + 1);
}
String end = "\r\n";
String Hyphens = "--";
String boundary = "WUm4580jbtwfJhNp7zi1djFEO3wNNm";
try {
URL url = new URL(uploadUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Charset", "UTF-8");
conn.setRequestProperty("Content-Type",
"multipart/form-data;boundary=" + boundary);
DataOutputStream ds = new DataOutputStream(conn.getOutputStream());
ds.writeBytes(Hyphens + boundary + end);
ds.writeBytes("Content-Disposition: form-data; "
+ "name=\"file1\";filename=\"" + fileName + "\"" + end);
ds.writeBytes(end);
FileInputStream fStream = new FileInputStream(uploadFile);
// 每次写入1024字节
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
int length = -1;
// 将文件数据写入到缓冲区
while((length = fStream.read(buffer)) != -1) {
ds.write(buffer, 0, length);
}
ds.writeBytes(end);
ds.writeBytes(Hyphens + boundary + Hyphens + end);
fStream.close();
ds.flush();
// 获取返回内容
InputStream is = conn.getInputStream();
int ch;
StringBuffer b = new StringBuffer();
while ((ch = is.read()) != -1) {
b.append((char) ch);
}
ds.close();
return "SUCC";
} catch (Exception e) {
e.printStackTrace();
return "上传失败:" + e.getMessage();
}
}
}
HttpURLConnection需要开发者自己拼接请求包,容易出错,并且处理单一不够灵活,因此涌现了几个开源的http框架,方便开发者进行http通信的编码。android-async-http是这其中使用较多的一个网络请求框架,它的项目地址在 https://github.com/loopj/android-async-http 。 据官方介绍,android-async-http是基于Apache HttpClient库之上的一个异步网络请求处理库,网络处理均基于Android的非UI线程,通过回调方法处理请求结果。这里我们使用该库进行文件上传,主要用到AsyncHttpClient类的post方法,要上传的文件信息放在RequestParams对象中。 下面是android-async-http上传文件的工具类代码:
import java.io.File;
import com.example.exmupload.MainActivity;
import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.RequestParams;
import android.util.Log;
public class AsyncUtil {
private static final String TAG = "AsyncUtil";
public static String upload(final MainActivity act, String uploadServlet, String filePath, boolean isBinary) {
try {
//服务端的commons-fileupload只支持multipart/form-data方式
//application/octet-stream表示任意的二进制文件,包括图片、音频、视频、压缩文件等等
String contentType = "application/octet-stream";
//String contentType = "multipart/form-data";
RequestParams params = new RequestParams();
if (isBinary == true) {
params.put("file", new File(filePath), contentType);
} else {
params.put("file", new File(filePath));
}
Log.d(TAG, "contentType="+contentType);
AsyncHttpClient client = new AsyncHttpClient();
//AsyncHttpResponseHandle不在ui线程运行,不能直接操作ui
//如果在此处定义AsyncHttpResponseHandle对象,则运行报错:
//java.lang.IllegalArgumentException: Synchronous ResponseHandler used in AsyncHttpClient. You should create your response handler in a looper thread or use SyncHttpClient instead.
client.post(uploadServlet, params, act.mAsyncHandler);
return "uploadByFile";
} catch (Exception e) {
e.printStackTrace();
return e.getMessage();
}
}
// //下面代码在MainActivity.java中定义
// public AsyncHttpResponseHandler mAsyncHandler = new AsyncHttpResponseHandler() {
// @Override
// public void onSuccess(int status, Header[] headers, byte[] data) {
// String result = "文件上传成功!";
// Message msg = Message.obtain();
// msg.what = ASYNC;
// msg.obj = result;
// mHandler.sendMessage(msg);
// }
//
// @Override
// public void onFailure(int status, Header[] headers, byte[] data, Throwable e) {
// String result = "文件上传失败!"+e.getMessage();
// Message msg = Message.obtain();
// msg.what = ASYNC;
// msg.obj = result;
// mHandler.sendMessage(msg);
// }
// };
}
Retrofit是网络请求框架中的后起之秀,它的项目地址在 https://github.com/square/retrofit 。据官方介绍,Retrofit是一个类型安全的REST客户端,用于Android平台。Retrofit基于注解方式,提供了JSON to POJO(Plain Ordinary Java Object,简单Java对象)、POJO to JSON、网络请求(POST/GET/PUT/DELETE)等通信行为的封装。 Retrofit依赖okhttp库,早期的版本用的是okhttp2(如okhttp-2.5.0.jar),最新的版本如retrofit-2.1.0.jar用的是okhttp3(如okhttp-3.3.1.jar),所以工程引用Retrofit库时,要注意导入正确的okhttp库。这里我们通过文件上传来演示Retrofit的使用方法,因为采用了注解方式,所以不太方便文字说明,还是直接上代码好了。 下面是Retrofit上传文件的工具类代码:
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import com.example.exmupload.MainActivity;
import okhttp3.MediaType;
import okhttp3.RequestBody;
import okhttp3.ResponseBody;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.http.Multipart;
import retrofit2.http.PartMap;
import retrofit2.http.POST;
import android.util.Log;
import android.webkit.MimeTypeMap;
public class RetrofitUtil {
private static final String TAG = "RetrofitUtil";
public interface ApiInterface {
//这里的POST是不带ip也不带域名的地址,下面uploadHost才带ip/域名和端口,如http://192.168.0.212:8080/
@Multipart
@POST("UploadTest/uploadServlet")
Call<ResponseBody> upload(@PartMap Map<String, RequestBody> params);
}
public static void upload(final MainActivity act, String uploadHost, String filePath) {
File file1 = new File(filePath);
Retrofit retrofit = new Retrofit.Builder().baseUrl(uploadHost).build();
ApiInterface apiService = retrofit.create(ApiInterface.class);
// 获取文件真实的内容类型
// String mimeType = MimeTypeMap.getSingleton()
// .getMimeTypeFromExtension(MimeTypeMap.getFileExtensionFromUrl(file1.getPath()));
// RequestBody fileBody = RequestBody.create(MediaType.parse(mimeType), filePath);
RequestBody fileBody = RequestBody.create(MediaType.parse("multipart/form-data"), filePath);
Map<String, RequestBody> params = new HashMap<>();
// 如果要上传多个文件,可对该Map对象进行put操作
params.put("file\"; filename=\"" + file1.getName() + "", fileBody);
Call<ResponseBody> call = apiService.upload(params);
call.enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
try {
String jsonString = new String(response.body().bytes()); // 这就是返回的json字符串了。
Log.d(TAG, "onResponse succ : "+jsonString);
act.notify(act.RETROFIT, "onResponse succ "+jsonString);
} catch (IOException e) {
e.printStackTrace();
act.notify(act.RETROFIT, "onResponse "+e.getMessage());
}
}
@Override
public void onFailure(Call<ResponseBody> call, Throwable throwable) {
Log.d(TAG, "onFailure : "+throwable.getMessage());
act.notify(act.RETROFIT, "onFailure "+throwable.getMessage());
}
});
}
}
文件上传需要服务器配合,服务端若用java编码,则可通过commons-fileupload来接收文件。commons-fileupload是个通用的各类网络协议通信包,包括ftp/telnet/smtp/pop3等协议。该包依赖于commons-io库,它们的下载地址如下: commons-fileupload-1.2.1.jar https://mirrors.tuna.tsinghua.edu.cn/apache/commons/fileupload/binaries/ commons-io-1.4.jar https://mirrors.tuna.tsinghua.edu.cn/apache/commons/io/binaries/ 下面是服务端采用commons-fileupload接收文件的代码例子:
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.Writer;
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;
import org.apache.commons.fileupload.util.Streams;
public class UploadServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public UploadServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
@SuppressWarnings("unchecked")
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("request.getContentType()="+request.getContentType());
response.setContentType("text/html");
response.setCharacterEncoding("UTF-8");
Writer o = response.getWriter();
//首先判断Content-Type是不是multipart/form-data。同时也判断了form的提交方式是不是post
if (ServletFileUpload.isMultipartContent(request)) {
request.setCharacterEncoding("utf-8");
// 实例化一个硬盘文件工厂,用来配置上传组件ServletFileUpload
DiskFileItemFactory factory = new DiskFileItemFactory();
//设置文件存放的临时文件夹,这个文件夹要真实存在
File fileDir = new File("../webapps/");
if (fileDir.isDirectory() && fileDir.exists()==false) {
fileDir.mkdir();
}
factory.setRepository(fileDir);
//设置最大占用的内存
factory.setSizeThreshold(1024000);
//创建ServletFileUpload对象
ServletFileUpload sfu = new ServletFileUpload(factory);
sfu.setHeaderEncoding("utf-8");
//设置单个文件最大值byte
sfu.setFileSizeMax(102400000);
//所有上传文件的总和最大值byte
sfu.setSizeMax(204800000);
List<FileItem> items = null;
try {
items = sfu.parseRequest(request);
System.out.println("items.size()="+items.size());
} catch(Exception e) {
e.printStackTrace();
}
Iterator<FileItem> iter = items==null?null:items.iterator();
//文件上传后存放的路径目录
File dir = new File("D:/");
if (dir.exists()==false) {
dir.mkdirs();
}
while (iter!=null && iter.hasNext()) {
FileItem item = (FileItem) iter.next();
if (item.isFormField()) { //如果传过来的是普通的表单域
System.out.print("普通的表单域:");
System.out.print(new String(item.getFieldName()) + " ");
System.out.println(new String(item.getString("UTF-8")));
} else if (!item.isFormField()) { //文件域
System.out.println("源文件:" + item.getName());
String fileName = item.getName();
if (fileName.indexOf("\\") >= 0) {
fileName = item.getName().substring(item.getName().lastIndexOf("\\"));
}
BufferedInputStream in = new BufferedInputStream(item.getInputStream());
BufferedOutputStream out = new BufferedOutputStream(
new FileOutputStream(new File(dir.getAbsolutePath()+ fileName)));
Streams.copy(in, out, true);
o.write("文件上传成功");
}
}
} else {
System.out.println("表单的Content-Type错误");
}
}
}
在从前带宽有限的互联网时代,FTP共享影视资源曾经盛行一时,如今宽带普及了,特别是步入移动互联网时代,FTP用的便越来越少了。不管怎样,作为一个技术手段,我们还是温习一下FTP上传文件的用法,java上可导入commons-net-3.3.jar,该库是集成了常见的网络通讯协议,包括但不限于:ftp、telnet、smtp、pop3等等。 commons-net进行FTP上传用的是FTPClient类,下面是FTPClient上传文件的工具类代码:
import java.io.FileInputStream;
import java.io.IOException;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPReply;
public class FTPUtil {
private static String mUurl;
private static String mPort;
private static String mUsername;
private static String mPassword;
public static void setUser(String url, String port, String username, String password) {
mUurl = url;
mPort = port;
mUsername = username;
mPassword = password;
}
public static String upload(String remotePath, String filePath, String fileName) {
FTPClient ftpClient = new FTPClient();
String result = "SUCC";
try {
ftpClient.connect(mUurl, Integer.parseInt(mPort));
boolean loginResult = ftpClient.login(mUsername, mPassword);
int returnCode = ftpClient.getReplyCode();
if (loginResult && FTPReply.isPositiveCompletion(returnCode)) { //登录成功
ftpClient.makeDirectory(remotePath);
// 设置上传目录
ftpClient.changeWorkingDirectory(remotePath);
ftpClient.setBufferSize(1024);
ftpClient.setControlEncoding("UTF-8");
ftpClient.enterLocalPassiveMode();
FileInputStream fis = new FileInputStream(filePath + fileName);
ftpClient.storeFile(fileName, fis);
} else { //登录失败
result = "FAIL";
}
} catch (IOException e) {
e.printStackTrace();
result = "FTP客户端出错!" + e.getMessage();
} finally {
try {
ftpClient.disconnect();
} catch (IOException e) {
e.printStackTrace();
result = "关闭FTP连接发生异常!" + e.getMessage();
}
}
return result;
}
}
SFTP是Secure FTP的简称,顾名思义它比FTP要安全。不过对于普通用户来说,SFTP用得比FTP还少,就不啰嗦了。 调用SFTP可导入JSch库,最新的jar包是jsch-0.1.53.jar,该库操作SFTP主要用ChannelSftp类,下面是JSch上传文件的工具类代码:
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Properties;
import java.util.Vector;
import android.util.Log;
import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.ChannelSftp.LsEntry;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.SftpException;
public class SFTPUtil {
private static final String TAG = "SFTPUtil";
public static int SUCC = 0;
public static int FAIL = -1;
//连接sftp服务器
public static ChannelSftp connect(String host, int port, String username, String password) {
ChannelSftp sftp = null;
try {
JSch jsch = new JSch();
jsch.getSession(username, host, port);
Session session = jsch.getSession(username, host, port);
session.setPassword(password);
Properties config = new Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
session.connect();
Channel channel = session.openChannel("sftp");
channel.connect();
sftp = (ChannelSftp) channel;
Log.d(TAG, "Connected to " + host + ".");
} catch (Exception e) {
e.printStackTrace();
}
return sftp;
}
//上传文件
public static String upload(ChannelSftp sftp, String directory, String uploadFile) {
try {
sftp.cd(directory);
File file = new File(uploadFile);
sftp.put(new FileInputStream(file), file.getName());
Log.d(TAG, "Upload succ. " + uploadFile);
return "SUCC";
} catch (Exception e) {
e.printStackTrace();
return e.getMessage();
}
}
//下载文件
public static int download(ChannelSftp sftp, String directory, String downloadFile, String saveFile) {
try {
sftp.cd(directory);
File file = new File(saveFile);
sftp.get(downloadFile, new FileOutputStream(file));
Log.d(TAG, "Download succ. " + downloadFile);
return SUCC;
} catch (Exception e) {
e.printStackTrace();
return FAIL;
}
}
//删除文件
public static int delete(ChannelSftp sftp, String directory, String deleteFile) {
try {
sftp.cd(directory);
sftp.rm(deleteFile);
Log.d(TAG, "Delete succ. " + deleteFile);
return SUCC;
} catch (Exception e) {
e.printStackTrace();
return FAIL;
}
}
//列出目录下的文件
public static Vector<?> listFiles(ChannelSftp sftp, String directory) throws SftpException {
//Vector容器内部保存的是LsEntry类型对象。
return sftp.ls(directory);
}
}
下面是文件上传(包括http上传和ftp上传)的页面代码例子:
import java.util.Map;
import org.apache.http.Header;
import com.aqi00.lib.dialog.FileSelectFragment;
import com.aqi00.lib.dialog.FileSelectFragment.FileSelectCallbacks;
import com.example.exmupload.util.AsyncUtil;
import com.example.exmupload.util.FTPUtil;
import com.example.exmupload.util.RetrofitUtil;
import com.example.exmupload.util.SFTPUtil;
import com.example.exmupload.util.UploadUtil;
import com.jcraft.jsch.ChannelSftp;
import com.loopj.android.http.AsyncHttpResponseHandler;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener,FileSelectCallbacks {
private static final String TAG = "MainActivity";
private static TextView tv_filename;
private Button btn_select;
private Button btn_upload;
private Button btn_async;
private Button btn_retrofit;
private Button btn_ftp;
private Button btn_sftp;
private static TextView tv_result;
public static String mUploadHost = "http://192.168.0.212:8080/";
public static String mUploadService = "UploadTest/uploadServlet";
private String mServletUrl = mUploadHost + mUploadService;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv_filename = (TextView) findViewById(R.id.tv_filename);
btn_select = (Button) findViewById(R.id.btn_select);
btn_upload = (Button) findViewById(R.id.btn_upload);
btn_async = (Button) findViewById(R.id.btn_async);
btn_retrofit = (Button) findViewById(R.id.btn_retrofit);
btn_ftp = (Button) findViewById(R.id.btn_ftp);
btn_sftp = (Button) findViewById(R.id.btn_sftp);
tv_result = (TextView) findViewById(R.id.tv_result);
btn_select.setOnClickListener(this);
btn_upload.setOnClickListener(this);
btn_async.setOnClickListener(this);
btn_retrofit.setOnClickListener(this);
btn_ftp.setOnClickListener(this);
btn_sftp.setOnClickListener(this);
}
@Override
public void onClick(View v) {
String file_path = tv_filename.getText().toString().trim();
if (v.getId() == R.id.btn_select) {
FileSelectFragment.show(this, new String[]{"jpg","png","gif","txt"}, null);
return;
}
if (file_path.length() <= 0) {
Toast.makeText(this, "请选择要上传的文件", Toast.LENGTH_LONG).show();
return;
}
if (v.getId() == R.id.btn_upload) {
tv_result.setText("开始HttpURLConnection上传");
new ConnnectionThread(file_path).start();
} else if (v.getId() == R.id.btn_async) {
tv_result.setText("开始async上传");
new AsyncThread(file_path).start();
} else if (v.getId() == R.id.btn_retrofit) {
tv_result.setText("开始retrofit上传");
new RetrofitThread(file_path).start();
} else if (v.getId() == R.id.btn_ftp) {
new FTPThread(file_path).start();
} else if (v.getId() == R.id.btn_sftp) {
new SFTPThread(file_path).start();
}
}
public void notify(int type, String message) {
Message msg = Message.obtain();
msg.what = type;
msg.obj = message;
mHandler.sendMessage(msg);
}
private class ConnnectionThread extends Thread {
private String mFilePath;
public ConnnectionThread(String file_path) {
mFilePath = file_path;
}
@Override
public void run() {
String result = UploadUtil.upload(mServletUrl, mFilePath);
MainActivity.this.notify(COMMON, "upload :" + result);
}
}
private class AsyncThread extends Thread {
private String mFilePath;
public AsyncThread(String file_path) {
mFilePath = file_path;
}
@Override
public void run() {
String result = AsyncUtil.upload(MainActivity.this, mServletUrl, mFilePath, true);
MainActivity.this.notify(ASYNC, "upload :" + result);
}
}
public AsyncHttpResponseHandler mAsyncHandler = new AsyncHttpResponseHandler() {
@Override
public void onSuccess(int status, Header[] headers, byte[] data) {
MainActivity.this.notify(ASYNC, "文件上传成功!");
}
@Override
public void onFailure(int status, Header[] headers, byte[] data, Throwable e) {
MainActivity.this.notify(ASYNC, "文件上传失败!"+e.getMessage());
}
};
private class RetrofitThread extends Thread {
private String mFilePath;
public RetrofitThread(String file_path) {
mFilePath = file_path;
}
@Override
public void run() {
RetrofitUtil.upload(MainActivity.this, mUploadHost, mFilePath);
}
}
private class FTPThread extends Thread {
private String mFilePath;
public FTPThread(String file_path) {
mFilePath = file_path;
}
@Override
public void run() {
String filepath = mFilePath.substring(0, mFilePath.lastIndexOf("/")+1);
String filename = mFilePath.substring(mFilePath.lastIndexOf("/")+1);
FTPUtil.setUser("172.16.16.146", "21", "testftp", "testftp");
String result = FTPUtil.upload("/home/testftp", filepath, filename);
MainActivity.this.notify(FTP, result);
}
}
private class SFTPThread extends Thread {
private String mFilePath;
public SFTPThread(String file_path) {
mFilePath = file_path;
}
@Override
public void run() {
ChannelSftp sftp = SFTPUtil.connect("172.16.16.133", 22, "oracle", "oracle");
String result = SFTPUtil.upload(sftp, "/home/oracle", mFilePath);
MainActivity.this.notify(SFTP, result);
}
}
public int COMMON = 0;
public int ASYNC = 1;
public int RETROFIT = 2;
public int FTP = 3;
public int SFTP = 4;
@SuppressLint("HandlerLeak")
public Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
String result = (String) msg.obj;
if (msg.what == COMMON) {
tv_result.setText(tv_result.getText().toString()+"\n"+result);
} else if (msg.what == ASYNC) {
tv_result.setText(tv_result.getText().toString()+"\n"+result);
} else if (msg.what == RETROFIT) {
tv_result.setText(tv_result.getText().toString()+"\n"+result);
} else if (msg.what == FTP) {
showTip("FTP文件上传结果:"+result);
} else if (msg.what == SFTP) {
showTip("sftp文件上传结果:"+result);
}
}
};
private void showTip(String desc) {
Toast.makeText(getApplicationContext(), desc, Toast.LENGTH_SHORT).show();
}
@Override
public void onConfirmSelect(String absolutePath, String fileName,
Map<String, Object> map_param) {
String path = absolutePath + "/" + fileName;
tv_filename.setText(path);
}
@Override
public boolean isFileValid(String absolutePath, String fileName,
Map<String, Object> map_param) {
return true;
}
}