Android学习之使用HttpURLConnection上传单个文件

package com.example.youyige.util;

import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.UUID;
import android.util.Log;

/**
*
* 实现文件上传的工具类
*
*/
public class UploadUtils {
private static final String TAG = "uploadFile";
private static final int TIME_OUT = 10*10000000;   //超时时间
private static final String CHARSET = "utf-8"; //设置编码
public static final String SUCCESS="1";
public static final String FAILURE="0";
/**
* android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 String uploadFile(File file,String RequestURL)
{
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，把文件包装并且上传
*/
OutputStream outputSteam=conn.getOutputStream();

DataOutputStream dos = new DataOutputStream(outputSteam);
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，包含后缀名的   比如:abc.png
*/

sb.append("Content-Disposition: form-data; name=\"img\"; 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
*/
int res = conn.getResponseCode();
Log.e(TAG, "response code:"+res);
if(res==200)
{
return SUCCESS;
}
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return FAILURE;
}
}