Android上传文件到Web服务器，PHP接收文件（2）

来源：互联网发布：网络文明安全调查问卷编辑：程序博客网时间：2024/05/07 00:35

接上一篇文章《Android上传文件到Web服务器，PHP接收文件（一）》 http://www.linuxidc.com/Linux/2012-02/54985.htm，这次在之前的基础上添加进度显示，Java代码如下所示：
1.package com.lenovo.uptest;
2.
3.import java.io.DataInputStream;
4.import java.io.DataOutputStream;
5.import java.io.File;
6.import java.io.FileInputStream;
7.import java.net.HttpURLConnection;
8.import java.net.URL;
9.
10.import android.app.Activity;
11.import android.app.AlertDialog;
12.import android.app.ProgressDialog;
13.import android.content.DialogInterface;
14.import android.os.AsyncTask;
15.import android.os.Bundle;
16.import android.view.View;
17.import android.widget.Button;
18.import android.widget.TextView;
19.
20.public class UploadtestActivity extends Activity {
21.    /** Called when the activity is first created. */
22.    /**
23.     * Upload file to web server with progress status, client: android;
24.     * server:php
25.     * **/
26.
27.    private TextView mtv1 = null;
28.    private TextView mtv2 = null;
29.    private Button bupload = null;
30.
31.    private String uploadFile = "/sdcard/testimg.jpg";
32.    private String actionUrl = "http://10.100.1.208/receive_file.php";
33.
34.    @Override
35.    public void onCreate(Bundle savedInstanceState) {
36.        super.onCreate(savedInstanceState);
37.        setContentView(R.layout.main);
38.
39.        mtv1 = (TextView) findViewById(R.id.mtv1);
40.        mtv1.setText("文件路径：\n" + uploadFile);
41.        mtv2 = (TextView) findViewById(R.id.mtv2);
42.        mtv2.setText("上传地址：\n" + actionUrl);
43.        bupload = (Button) findViewById(R.id.bupload);
44.        bupload.setOnClickListener(new View.OnClickListener() {
45.
46.            @Override
47.            public void onClick(View v) {
48.                // TODO Auto-generated method stub
49.                FileUploadTask fileuploadtask = new FileUploadTask();
50.                fileuploadtask.execute();
51.            }
52.        });
53.    }
54.
55.    // show Dialog method
56.    private void showDialog(String mess) {
57.        new AlertDialog.Builder(UploadtestActivity.this).setTitle("Message")
58.                .setMessage(mess)
59.                .setNegativeButton("确定", new DialogInterface.OnClickListener() {
60.                    @Override
61.                    public void onClick(DialogInterface dialog, int which) {
62.                    }
63.                }).show();
64.    }
65.
66.    class FileUploadTask extends AsyncTask<Object, Integer, Void> {
67.
68.        private ProgressDialog dialog = null;
69.        HttpURLConnection connection = null;
70.        DataOutputStream outputStream = null;
71.        DataInputStream inputStream = null;
72.        //the file path to upload
73.        String pathToOurFile = "/sdcard/testimg.jpg";
74.        //the server address to process uploaded file
75.        String urlServer = "http://10.100.1.208/receive_file.php";
76.        String lineEnd = "\r\n";
77.        String twoHyphens = "--";
78.        String boundary = "*****";
79.
80.        File uploadFile = new File(pathToOurFile);
81.        long totalSize = uploadFile.length(); // Get size of file, bytes
82.
83.        @Override
84.        protected void onPreExecute() {
85.            dialog = new ProgressDialog(UploadtestActivity.this);
86.            dialog.setMessage("正在上传...");
87.            dialog.setIndeterminate(false);
88.            dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
89.            dialog.setProgress(0);
90.            dialog.show();
91.        }
92.
93.        @Override
94.        protected Void doInBackground(Object... arg0) {
95.
96.            long length = 0;
97.            int progress;
98.            int bytesRead, bytesAvailable, bufferSize;
99.            byte[] buffer;
100.            int maxBufferSize = 256 * 1024;// 256KB
101.
102.            try {
103.                FileInputStream fileInputStream = new FileInputStream(new File(
104.                        pathToOurFile));
105.
106.                URL url = new URL(urlServer);
107.                connection = (HttpURLConnection) url.openConnection();
108.
109.                // Set size of every block for post
110.                connection.setChunkedStreamingMode(256 * 1024);// 256KB
111.
112.                // Allow Inputs & Outputs
113.                connection.setDoInput(true);
114.                connection.setDoOutput(true);
115.                connection.setUseCaches(false);
116.
117.                // Enable POST method
118.                connection.setRequestMethod("POST");
119.                connection.setRequestProperty("Connection", "Keep-Alive");
120.                connection.setRequestProperty("Charset", "UTF-8");
121.                connection.setRequestProperty("Content-Type",
122.                        "multipart/form-data;boundary=" + boundary);
123.
124.                outputStream = new DataOutputStream(
125.                        connection.getOutputStream());
126.                outputStream.writeBytes(twoHyphens + boundary + lineEnd);
127.                outputStream
128.                        .writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\""
129.                                + pathToOurFile + "\"" + lineEnd);
130.                outputStream.writeBytes(lineEnd);
131.
132.                bytesAvailable = fileInputStream.available();
133.                bufferSize = Math.min(bytesAvailable, maxBufferSize);
134.                buffer = new byte[bufferSize];
135.
136.                // Read file
137.                bytesRead = fileInputStream.read(buffer, 0, bufferSize);
138.
139.                while (bytesRead > 0) {
140.                    outputStream.write(buffer, 0, bufferSize);
141.                    length += bufferSize;
142.                    progress = (int) ((length * 100) / totalSize);
143.                    publishProgress(progress);
144.
145.                    bytesAvailable = fileInputStream.available();
146.                    bufferSize = Math.min(bytesAvailable, maxBufferSize);
147.                    bytesRead = fileInputStream.read(buffer, 0, bufferSize);
148.                }
149.                outputStream.writeBytes(lineEnd);
150.                outputStream.writeBytes(twoHyphens + boundary + twoHyphens
151.                        + lineEnd);
152.                publishProgress(100);
153.
154.                // Responses from the server (code and message)
155.                int serverResponseCode = connection.getResponseCode();
156.                String serverResponseMessage = connection.getResponseMessage();
157.
158.                /* 将Response显示于Dialog */
159.                // Toast toast = Toast.makeText(UploadtestActivity.this, ""
160.                // + serverResponseMessage.toString().trim(),
161.                // Toast.LENGTH_LONG);
162.                // showDialog(serverResponseMessage.toString().trim());
163.                /* 取得Response内容 */
164.                // InputStream is = connection.getInputStream();
165.                // int ch;
166.                // StringBuffer sbf = new StringBuffer();
167.                // while ((ch = is.read()) != -1) {
168.                // sbf.append((char) ch);
169.                // }
170.                //
171.                // showDialog(sbf.toString().trim());
172.
173.                fileInputStream.close();
174.                outputStream.flush();
175.                outputStream.close();
176.
177.            } catch (Exception ex) {
178.                // Exception handling
179.                // showDialog("" + ex);
180.                // Toast toast = Toast.makeText(UploadtestActivity.this, "" +
181.                // ex,
182.                // Toast.LENGTH_LONG);
183.
184.            }
185.            return null;
186.        }
187.
188.        @Override
189.        protected void onProgressUpdate(Integer... progress) {
190.            dialog.setProgress(progress[0]);
191.        }
192.
193.        @Override
194.        protected void onPostExecute(Void result) {
195.            try {
196.                dialog.dismiss();
197.                // TODO Auto-generated method stub
198.            } catch (Exception e) {
199.            }
200.        }
201.
202.    }
203.}

服务器端仍然和之前的一样。

这里使用了AsyncTask，它使创建需要与用户界面交互的长时间运行的任务变得更简单，适用于简单的异步处理，不需要借助线程和Handler即可实现。

AsyncTask是抽象类.AsyncTask定义了三种泛型类型 Params，Progress和Result。

　　Params 启动任务执行的输入参数，比如HTTP请求的URL。

　　Progress 后台任务执行的百分比。

　　Result 后台执行任务最终返回的结果，比如String。

AsyncTask的执行分为四个步骤，每一步都对应一个回调方法，这些方法不应该由应用程序调用，开发者需要做的就是实现这些方法。

　　1) 子类化AsyncTask

　　2) 实现AsyncTask中定义的下面一个或几个方法

　　onPreExecute(), 该方法将在执行实际的后台操作前被UI thread调用。可以在该方法中做一些准备工作，如在界面上显示一个进度条。

　　doInBackground(Params...), 将在onPreExecute 方法执行后马上执行，该方法运行在后台线程中。这里将主要负责执行那些很耗时的后台计算工作。可以调用 publishProgress方法来更新实时的任务进度。该方法是抽象方法，子类必须实现。

　　onProgressUpdate(Progress...),在publishProgress方法被调用后，UI thread将调用这个方法从而在界面上展示任务的进展情况，例如通过一个进度条进行展示。

　　onPostExecute(Result), 在doInBackground 执行完成后，onPostExecute 方法将被UI thread调用，后台的计算结果将通过该方法传递到UI thread.

为了正确的使用AsyncTask类，以下是几条必须遵守的准则：

　　1) Task的实例必须在UI thread中创建

　　2) execute方法必须在UI thread中调用

　　3) 不要手动的调用onPreExecute(), onPostExecute(Result)，doInBackground(Params...), onProgressUpdate(Progress...)这几个方法

　　4) 该task只能被执行一次，否则多次调用时将会出现异常

doInBackground方法和onPostExecute的参数必须对应，这两个参数在AsyncTask声明的泛型参数列表中指定，第一个为doInBackground接受的参数，第二个为显示进度的参数，第三个为doInBackground返回和onPostExecute传入的参数。

运行结果如下：

Android上传文件到Web服务器，PHP接收文件

运行结果如下：