Android通過Base64往服務器上傳圖片和對象

點擊這裡在下載Base64.java文件,分別添加到客戶端和服務器端.

1>我們知道在web中實現文件上傳可以通過apache的項目,那麼在Android中把文件上傳到服務器端,當然也可以通過該方式,但是也可以通過base64,

這樣就相當於把一個字符串傳到服務器,然後在服務器端通過Base64.decode()方法解碼接口,返回的字節數組byte[]

在android side:

1. public class MainActivity extends Activity {
2. InputStream is = null;
4. @Override
5. public void onCreate(Bundle icicle) {
7. super.onCreate(icicle);
9. setContentView(R.layout.main);
11. Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),
13. R.drawable.a1);
15. ByteArrayOutputStream bao = new ByteArrayOutputStream();
17. bitmapOrg.compress(Bitmap.CompressFormat.PNG, 90, bao);
19. byte[] ba = bao.toByteArray();
21. String ba1 = Base64.encodeBytes(ba);
23. ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
25. nameValuePairs.add(new BasicNameValuePair("image", ba1));
27. try {
29. HttpClient httpclient = new DefaultHttpClient();
31. HttpPost httppost = new
33. HttpPost(
34. "http://192.168.0.101:8080/ServletClassloadTest/servlet/UploadImage");
36. httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
38. HttpResponse response = httpclient.execute(httppost);
40. HttpEntity entity = response.getEntity();
42. is = entity.getContent();
44. } catch (Exception e) {
46. Log.e("log_tag", "Error in http connection " + e.toString());
48. }
50. }
51. }

在server side:

1. String result = request.getParameter("image")
2. byte[] result = Base64.decode()
3. OutputStream out = new FileOutputStream("C:\\a.png");
4. out.write(result);
5. out.close();

測試結果:在C盤找到如下文件

2>同理我們也可以在客戶端把對象傳遞到服務器端.(這是把多個對象傳遞給服務器端,傳遞單個對象更加簡單)
在android side:

1. public void onCreate(Bundle icicle) {
2. super.onCreate(icicle);
3. setContentView(R.layout.main);
4. Collect conCollect = new Collect(new Person[]{new Person("yzq",12),new Person("johnny",21)});
5. String ba1 = null;
6. try {
7. ba1 = Base64.encodeObject(conCollect);
8. } catch (IOException e) {
9. e.printStackTrace();
11. ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
13. nameValuePairs.add(new BasicNameValuePair("image", ba1));
15. try {
17. HttpClient httpclient = new DefaultHttpClient();
19. HttpPost httppost = new
21. HttpPost(
22. "http://192.168.0.101:8080/ServletClassloadTest/servlet/UploadImage");
24. httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
26. HttpResponse response = httpclient.execute(httppost);
28. HttpEntity entity = response.getEntity();
30. is = entity.getContent();
32. } catch (Exception e) {
34. Log.e("log_tag", "Error in http connection " + e.toString());
36. }
38. }

Person類

1. public class Person implements Serializable{
3. private String name;
4. private int age;
6. public Person(String name, int age) {
7. super();
8. this.name = name;
9. this.age = age;
10. }
12. public String getName() {
13. return name;
14. }
16. public void setName(String name) {
17. this.name = name;
18. }
20. public int getAge() {
21. return age;
22. }
24. public void setAge(int age) {
25. this.age = age;
26. }
27. }
28. Collect 類
29. public class Collect implements Serializable{
31. public Person[] ps;
33. public Collect(Person[] ps) {
34. super();
35. this.ps = ps;
36. }
37. }

在server side:

1. public void doPost(HttpServletRequest request, HttpServletResponse response)
2. throws ServletException, IOException {
3. response.setContentType("text/html");
4. String image = request.getParameter("image");
5. System.out.println("result"+image);
6. try {
7. Collect collect = (Collect)com.ieheima.servlet.Base64.decodeToObject(image);
9. Person[] ps = collect.ps;
10. System.out.println("長度:"+ps.length);
11. for (int i = 0; i < ps.length; i++) {
12. System.out.println(ps[i].getName());
13. }
14. } catch (ClassNotFoundException e) {
15. e.printStackTrace();
16. }
17. }

在控制台輸出結果:

需要注意的是在服務器端也要有相同的類Collect和Person,同時包名也要一樣.如果傳輸的對象過大,可能會導致內存溢出.

還需要給實現了Serializable接口的類,定一個一個serialVersionUID

希望以上Base64的講解能夠對讀者有幫助,如果有什麼錯誤盡情讀者批評之處,不勝感謝。