android上面图片的上传可以用apache包里面的httpclient和MultipartEntity来上传图片，这种的上传方式的话由于都封装好了所以看不到HTTP协议里面具体是怎样上传的；
其实图片的上传还可以用Java自带的HttpURLConnection来做上传处理，例如有一个PHP写的接收图片的POST接口http://localhost/upload/upload.php，参数如下：
name 名称
address 地点
img[] 图片(支持多张图片上传)
这时假如我们上传的参数为：
name值为this is the parameter:name
address值为this is the parameter:address
img[]的值为两张图片，路径为E:\Photos\test_1.jpg 和E:\Photos\test_2.jpg
那么我们写的POST网络请求的方法体应该为下面的格式：
-----------------------------7dc2fd5c0894
Content-Disposition: form-data; name="name"
this is the parameter:name
-----------------------------7dc2fd5c0894
Content-Disposition: form-data; name="address"
this is the parameter:address
-----------------------------7dc2fd5c0894
Content-Disposition: form-data; name="img[]"; filename="E:\Photos\test_1.jpg"
Content-Type: image/pjpeg
<图片E:\Photos\test_1.jpg的二进制数据未显示>
---------------------------7dc2fd5c0894
Content-Disposition: form-data; name="img[]"; filename="E:\Photos\test_2.jpg"
Content-Type: image/pjpeg
<图片E:\Photos\test_2.jpg的二进制数据未显示 >
-----------------------------7dc2fd5c0894--
根据上面的格式我们写的上传图片的Java代码如下：
import
java.io.BufferedReader;
import
java.io.DataInputStream;
import
java.io.DataOutputStream;
import
java.io.File;
import
java.io.FileInputStream;
import
java.io.InputStreamReader;
import
java.io.OutputStream;
import
java.net.HttpURLConnection;
import
java.net.URL;
import
java.util.ArrayList;
import
java.util.List;
public
class
Main {
public
static
void
main(String[] args) {
List list =
new
ArrayList();
list.add(
"E:\\Photos\\test_1.jpg"
);
//要上传的文件路径
list.add(
"E:\\Photos\\test_2.jpg"
);
//要上传的文件路径
upload(
"this is the parameter:name"
,
"this is the parameter:address"
,
list);
}
public
static
void
upload(String name, String address, List list) {
try
{
// 定义数据分隔线
String BOUNDARY =
"------------------------7dc2fd5c0894"
;
// 定义最后数据分隔线
byte
[] end_data = (
"\r\n--"
+ BOUNDARY +
"--\r\n"
).getBytes();
URL url =
new
URL(
"http://localhost/upload/upload.php"
);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(
true
);
conn.setDoInput(
true
);
conn.setUseCaches(
false
);
conn.setRequestMethod(
"POST"
);
conn.setRequestProperty(
"connection"
,
"Keep-Alive"
);
conn.setRequestProperty(
"user-agent"
,
"Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0)"
);
conn.setRequestProperty(
"Charsert"
,
"UTF-8"
);
conn.setRequestProperty(
"Content-Type"
,
"multipart/form-data; boundary="
+ BOUNDARY);
OutputStream out =
new
DataOutputStream(conn.getOutputStream());
// name参数
StringBuffer params =
new
StringBuffer();
params.append(
"--"
+ BOUNDARY +
"\r\n"
);
params.append(
"Content-Disposition: form-data; name=\"name\"\r\n\r\n"
);
params.append(name);
params.append(
"\r\n"
);
// address参数
params.append(
"--"
+ BOUNDARY +
"\r\n"
);
params.append(
"Content-Disposition: form-data; name=\"address\"\r\n\r\n"
);
params.append(address);
params.append(
"\r\n"
);
out.write(params.toString().getBytes());
int
leng = list.size();
for
(
int
i =
0
; i < leng; i++) {
String fname = list.get(i);
File file =
new
File(fname);
StringBuilder sb =
new
StringBuilder();
sb.append(
"--"
);
sb.append(BOUNDARY);
sb.append(
"\r\n"
);
sb.append(
"Content-Disposition: form-data;name=\"img[]\";filename=\""
+ file.getName() +
"\"\r\n"
);
// 这里不能漏掉，根据文件类型来来做处理，由于上传的是图片，所以这里可以写成image/pjpeg
sb.append(
"Content-Type:image/pjpeg\r\n\r\n"
);
out.write(sb.toString().getBytes());
DataInputStream in =
new
DataInputStream(
new
FileInputStream(
file));
int
bytes =
0
;
byte
[] bufferOut =
new
byte
[
1024
];
while
((bytes = in.read(bufferOut)) != -
1
) {
out.write(bufferOut,
0
, bytes);
}
out.write(
"\r\n"
.getBytes());
in.close();
}
out.write(end_data);
out.flush();
out.close();
// 定义BufferedReader输入流来读取URL的响应
BufferedReader reader =
new
BufferedReader(
new
InputStreamReader(
conn.getInputStream()));
String line =
null
;
while
((line = reader.readLine()) !=
null
) {
System.out.println(line);
}
}
catch
(Exception e) {
System.out.println(
"发送POST请求出现异常！"
+ e);
e.printStackTrace();
}
}
}
这样就可以把多张图片和参数上传到服务器了。当然这里只是一个演示，是用php写的接口并只是简单的把图图片保存在了接口文件的当前文件夹下；另外图片也没有做压缩，android手机上面上传时一般会做压缩，而且也不会一个接口上传多张图片，网络差时给用户的体验很不好，但是对于互联网开发者来说深入理解HTTP协议对表单是怎样处理的这个还是很重要
