关于android图片的传输，android图片传输方式，xml传输图片，android 使用base64编码图片使用xml传输图片

android客服端上传图片到服务器，使用的xml来传输base64编码后的图片
我使用的是android自带的httpclient来发送post请求的，我也想过自己使用post方式来发送数据，但是，数据在服务器端进行base64解码的时候保存，我也没找出原因，所以就没写出来了

发送post请求就是因为post允许一次传输的数据量大，因为图片经过base64编码后，数据量大，如果采用get或者其他的方式来传输数据，传输效率不过，而且数据量大小受到限制

1.获取android客服端图片

//对文件的操作
FileInputStream in = new FileInputStream(Environment.getExternalStorageDirectory() + "/images/musicmax.png");
byte buffer[] = StreamUtil.read(in);//把图片文件流转成byte数组
byte[] encod = Base64.encode(buffer,Base64.DEFAULT);//使用base64编码

  //对文件的操作
  FileInputStream in = new FileInputStream(Environment.getExternalStorageDirectory() + "/images/musicmax.png");
  byte buffer[] = StreamUtil.read(in);//把图片文件流转成byte数组
  byte[] encod = Base64.encode(buffer,Base64.DEFAULT);//使用base64编码

2.发送post请求，注意android客服端访问网络记得要加访问网络的权限

String path ="http://192.168.1.173:7999/videonews/TestServlet";
Map<String, String> params = new HashMap<String, String>();//定义一个保存key-value的Map用于保存需要传输的数据

params.put("value", new String(encod));//保存数据到map对象
Log.i(TAG,new String(encod));
if(StreamUtil.sendHttpClientPOSTRequest(path, params, "utf-8")){//使用帮助类来发送HttpClient来发送post请求
Log.i(TAG, "success :" + path + "----:decode:----" + new String(Base64.decode(encod, Base64.DEFAULT)));
}

 String path ="http://192.168.1.173:7999/videonews/TestServlet"; 
 Map<String, String> params = new HashMap<String, String>();//定义一个保存key-value的Map用于保存需要传输的数据
 
 params.put("value", new String(encod));//保存数据到map对象
 Log.i(TAG,new String(encod));
 if(StreamUtil.sendHttpClientPOSTRequest(path, params, "utf-8")){//使用帮助类来发送HttpClient来发送post请求
  Log.i(TAG, "success :" + path + "----:decode:----" + new String(Base64.decode(encod, Base64.DEFAULT)));
 }

2.服务器端的代码

String value = request.getParameter("value");//获取value的值
FileOutputStream fileout = new FileOutputStream("c:/music.png");//设置文件保存在服务器的什么位置
fileout.write(com.sun.org.apache.xml.internal.security.utils.Base64.decode(value.getBytes()));//使用base64解码
fileout.close();

String value = request.getParameter("value");//获取value的值
 FileOutputStream fileout = new FileOutputStream("c:/music.png");//设置文件保存在服务器的什么位置
 fileout.write(com.sun.org.apache.xml.internal.security.utils.Base64.decode(value.getBytes()));//使用base64解码
 fileout.close();

StreamUtil帮助类里面完整代码

public class StreamUtil {
/**
* 返回字节数组
*
* @param in输入的流
* @return
* @throws Exception
*/

public static byte[] read(InputStream in) throws Exception {
ByteArrayOutputStream out = new ByteArrayOutputStream();
if (in != null) {
byte[] buffer = new byte[1024];
int length = 0;
while ((length = in.read(buffer)) != -1) {
out.write(buffer, 0, length);
}
out.close();
in.close();
return out.toByteArray();
}
return null;
}

/**
* 采用HttpClient发送POST请求
* @param path 请求路径
* @param params 请求参数
* @throws Exception
*/
public static boolean sendHttpClientPOSTRequest(String path, Map<String, String> params, String encoding) throws Exception{
List<NameValuePair> param = new ArrayList<NameValuePair>();
if(params!=null && !params.isEmpty()){
for(Map.Entry<String, String> entry : params.entrySet()){
param.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
}
}
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(param, encoding);
HttpPost post = new HttpPost(path);
// HttpGet get = new HttpGet();
post.setEntity(entity);
DefaultHttpClient client = new DefaultHttpClient();
HttpResponse response = client.execute(post);
if(response.getStatusLine().getStatusCode() == 200){
// response.getEntity().getContent();//获取服务器返回的数据
return true;
}
return false;
}
}

public class StreamUtil {
 /**
  * 返回字节数组
  * 
  * @param in输入的流
  * @return
  * @throws Exception
  */

 public static byte[] read(InputStream in) throws Exception {
  ByteArrayOutputStream out = new ByteArrayOutputStream();
  if (in != null) {
   byte[] buffer = new byte[1024];
   int length = 0;
   while ((length = in.read(buffer)) != -1) {
    out.write(buffer, 0, length);
   }
   out.close();
   in.close();
   return out.toByteArray();
  }
  return null;
 }
 
 /**
  * 采用HttpClient发送POST请求
  * @param path 请求路径
  * @param params 请求参数
  * @throws Exception
  */
 public static boolean sendHttpClientPOSTRequest(String path, Map<String, String> params, String encoding) throws Exception{
  List<NameValuePair> param = new ArrayList<NameValuePair>();
  if(params!=null && !params.isEmpty()){
   for(Map.Entry<String, String> entry : params.entrySet()){
    param.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
   }
  }
  UrlEncodedFormEntity entity = new UrlEncodedFormEntity(param, encoding);
  HttpPost post = new HttpPost(path);
//  HttpGet get = new HttpGet();
  post.setEntity(entity);
  DefaultHttpClient client = new DefaultHttpClient();
  HttpResponse response = client.execute(post);
  if(response.getStatusLine().getStatusCode() == 200){
//   response.getEntity().getContent();//获取服务器返回的数据
   return true;
  }
  return false;
 }
}

关于自己写post请求的代码，这个代码我测试过，在服务器对传输过来的数据进行base64解码的时候总报错，具体的原因我也没找出来，下面我贴出来代码，希望朋友们帮我找找原因

/*//对文件的操作 注:此方法测试有问题
FileInputStream in = new FileInputStream(Environment.getExternalStorageDirectory() + "/images/musicmax.png");
byte buffer[] = StreamUtil.read(in);
byte[] encod = Base64.encode(buffer,Base64.DEFAULT);

StringBuffer sb = new StringBuffer("value=");
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();

conn.setConnectTimeout(5 *  1000);
conn.setRequestMethod("POST");
conn.setDoOutput(true);//允许对外输出数据
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Length", (sb.toString().getBytes().length + encod.length) + "");
OutputStream outs = conn.getOutputStream();
outs.write(sb.toString().getBytes());
outs.write(encod);
outs.close();
Log.i(TAG,new String(encod));
if(conn.getResponseCode() ==  200){
Log.i(TAG, "success :" + path + "----:decode:----" + new String(Base64.decode(encod, Base64.DEFAULT)));
//下面的代码是测试是否解码后能生成对应的图片没
// FileOutputStream fileout = new FileOutputStream(Environment.getExternalStorageDirectory() + "/images/musicmax1.png");
// fileout.write(Base64.decode(encod, Base64.DEFAULT));
// fileout.close();
}

/*//对文件的操作  注:此方法测试有问题
					FileInputStream in = new FileInputStream(Environment.getExternalStorageDirectory() + "/images/musicmax.png");
					byte buffer[] = StreamUtil.read(in);
					byte[] encod = Base64.encode(buffer,Base64.DEFAULT);
					
					StringBuffer sb = new StringBuffer("value=");
					URL url = new URL(path);
					HttpURLConnection conn = (HttpURLConnection) url.openConnection();
					
					conn.setConnectTimeout(5 * 1000);
					conn.setRequestMethod("POST");
					conn.setDoOutput(true);//允许对外输出数据
					conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
					conn.setRequestProperty("Content-Length", (sb.toString().getBytes().length + encod.length) + "");
					OutputStream outs = conn.getOutputStream();
										outs.write(sb.toString().getBytes());
					outs.write(encod);
					outs.close();
					Log.i(TAG,new String(encod));
					if(conn.getResponseCode() == 200){
												Log.i(TAG, "success :" + path + "----:decode:----" + new String(Base64.decode(encod, Base64.DEFAULT)));
//下面的代码是测试是否解码后能生成对应的图片没
//						FileOutputStream fileout = new FileOutputStream(Environment.getExternalStorageDirectory() + "/images/musicmax1.png");
//						fileout.write(Base64.decode(encod, Base64.DEFAULT));
//						fileout.close();
					}