Android 上传图片到服务器

界面很简单，点击 【选择图片】，从图库里选择图片，显示到下面的imageview里，点击上传，就会上传到指定的服务器



布局文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="选择图片"
android:id="@+id/selectImage"
/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="上传图片"
android:id="@+id/uploadImage"
/>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView"
/>
</LinearLayout>

Upload Activity：

public class Upload extends Activity implements OnClickListener {
private static String requestURL = "http://192.168.1.212:8011/pd/upload/fileUpload.do";
private Button selectImage, uploadImage;
private ImageView imageView;

private String picPath = null;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.upload);

selectImage = (Button) this.findViewById(R.id.selectImage);
uploadImage = (Button) this.findViewById(R.id.uploadImage);
selectImage.setOnClickListener(this);
uploadImage.setOnClickListener(this);

imageView = (ImageView) this.findViewById(R.id.imageView);

}

@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.selectImage:
/***
* 这个是调用android内置的intent，来过滤图片文件 ，同时也可以过滤其他的
*/
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(intent, 1);
break;
case R.id.uploadImage:
if (picPath == null) {

Toast.makeText(Upload.this, "请选择图片！", 1000).show();
} else {
final File file = new File(picPath);

if (file != null) {
String request = UploadUtil.uploadFile(file, requestURL);
uploadImage.setText(request);
}
}
break;
default:
break;
}
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == Activity.RESULT_OK) {
/**
* 当选择的图片不为空的话，在获取到图片的途径
*/
Uri uri = data.getData();
Log.e(TAG, "uri = " + uri);
try {
String[] pojo = { MediaStore.Images.Media.DATA };

Cursor cursor = managedQuery(uri, pojo, null, null, null);
if (cursor != null) {
ContentResolver cr = this.getContentResolver();
int colunm_index = cursor
.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
String path = cursor.getString(colunm_index);
/***
* 这里加这样一个判断主要是为了第三方的软件选择，比如：使用第三方的文件管理器的话，你选择的文件就不一定是图片了，
* 这样的话，我们判断文件的后缀名 如果是图片格式的话，那么才可以
*/
if (path.endsWith("jpg") || path.endsWith("png")) {
picPath = path;
Bitmap bitmap = BitmapFactory.decodeStream(cr
.openInputStream(uri));
imageView.setImageBitmap(bitmap);
} else {
alert();
}
} else {
alert();
}

} catch (Exception e) {
}
}

super.onActivityResult(requestCode, resultCode, data);
}

private void alert() {
Dialog dialog = new AlertDialog.Builder(this).setTitle("提示")
.setMessage("您选择的不是有效的图片")
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
picPath = null;
}
}).create();
dialog.show();
}

}

这个才是重点 UploadUtil:

public class UploadUtil {
private static final String TAG = "uploadFile";
private static final int TIME_OUT = 10 * 1000; // 超时时间
private static final String CHARSET = "utf-8"; // 设置编码
/**
* 上传文件到服务器
* @param file 需要上传的文件
* @param RequestURL 请求的rul
* @return 返回响应的内容
*/
public static int uploadFile(File file, String RequestURL) {
int res=0;
String result = null;
String BOUNDARY = UUID.randomUUID().toString(); // 边界标识 随机生成
String PREFIX = "--", LINE_END = "\r\n";
String CONTENT_TYPE = "multipart/form-data"; // 内容类型

try {
URL url = new URL(RequestURL);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(TIME_OUT);
conn.setConnectTimeout(TIME_OUT);
conn.setDoInput(true); // 允许输入流
conn.setDoOutput(true); // 允许输出流
conn.setUseCaches(false); // 不允许使用缓存
conn.setRequestMethod("POST"); // 请求方式
conn.setRequestProperty("Charset", CHARSET); // 设置编码
conn.setRequestProperty("connection", "keep-alive");
conn.setRequestProperty("Content-Type", CONTENT_TYPE + ";boundary="+ BOUNDARY);

if (file != null) {
/**
* 当文件不为空时执行上传
*/
DataOutputStream dos = new DataOutputStream(conn.getOutputStream());
StringBuffer sb = new StringBuffer();
sb.append(PREFIX);
sb.append(BOUNDARY);
sb.append(LINE_END);
/**
* 这里重点注意： name里面的值为服务器端需要key 只有这个key 才可以得到对应的文件
* filename是文件的名字，包含后缀名
*/

sb.append("Content-Disposition: form-data; name=\"file\"; filename=\""
+ file.getName() + "\"" + LINE_END);
sb.append("Content-Type: application/octet-stream; charset="
+ CHARSET + LINE_END);
sb.append(LINE_END);
dos.write(sb.toString().getBytes());
InputStream is = new FileInputStream(file);
byte[] bytes = new byte[1024];
int len = 0;
while ((len = is.read(bytes)) != -1) {
dos.write(bytes, 0, len);
}
is.close();
dos.write(LINE_END.getBytes());
byte[] end_data = (PREFIX + BOUNDARY + PREFIX + LINE_END)
.getBytes();
dos.write(end_data);
dos.flush();
/**
* 获取响应码 200=成功 当响应成功，获取响应的流
*/
res = conn.getResponseCode();
Log.e(TAG, "response code:" + res);
if (res == 200) {
Log.e(TAG, "request success");
InputStream input = conn.getInputStream();
StringBuffer sb1 = new StringBuffer();
int ss;
while ((ss = input.read()) != -1) {
sb1.append((char) ss);
}
result = sb1.toString();
Log.e(TAG, "result : " + result);
} else {
Log.e(TAG, "request error");
}
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return res;
}
}

来自：http://blog.csdn.net/onlyonecoder/article/details/8687395

以上客户端的代码就完成了，下面是服务器端的代码，使用的是servlet:

摘自：http://my.oschina.net/u/2008084/blog/524937