Java客户端通过Http发送POST请求上传文件到web服务器

import java.io.BufferedInputStream;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;

import com.sys.common.log.Log;

/**
*
*/

/**
* 使用HttpURLConnection对象模拟测试后台接口
* @author
*
*/
public class MyHttpURLConnection {

private static String HTTP_URL="http://www.baidu.com";
private static String	HTTP_METHOD_POST="POST";

public static void main(String[] args) {

try {
System.out.println(	MyHttpURLConnection.sendHttp(""));
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

/**
* 模拟HTTP 请求 提交普通数据
*
* @param postData
*            发送数据
* @return
*/
private static String sendHttp(String postData) throws Exception {
if (HTTP_URL == null || "".equals(HTTP_URL)) {
throw new Exception("请传入远程请求地址");
}
String result = "";
BufferedWriter out = null;
BufferedInputStream reader = null;
HttpURLConnection connection = null;
try {
URL u = new URL(HTTP_URL);
connection = (HttpURLConnection) u.openConnection();
int code;
connection.setDoOutput(true);//是否向connection输出
connection.setUseCaches(false);//因为是post请求所以不能使用缓存
connection.setConnectTimeout(120000); // 连接超时为120秒
connection.setRequestMethod(HTTP_METHOD_POST);
//告诉服务端 要发送数据的长度
connection.setRequestProperty("Content-Length",
postData.getBytes("UTF-8").length + "");
//告诉服务器客户端浏览器内核
connection.setRequestProperty("User-Agent", "Mozilla/4.0");
//告诉服务器 要发送数据的格式和字符编码
connection.setRequestProperty("Content-Type",
"text/xml;charset=UTF-8");
//通过connection连接对象获取输出流对象
out = new BufferedWriter(new OutputStreamWriter(
connection.getOutputStream(), "UTF-8"));
//将需要想客户端发送的信息写入到输出流  刷新输出流并且关闭流
out.write(postData);
out.flush();
out.close();
out = null;
code = connection.getResponseCode();
if (code == HttpURLConnection.HTTP_OK) {
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
reader = new BufferedInputStream(connection.getInputStream());
int b;
byte[] bit = new byte[1024];
while (-1 != (b = reader.read(bit))) {
byteArrayOutputStream.write(bit, 0, b);
}
result = new String(byteArrayOutputStream.toByteArray());
} else {
Log.error("post ResponseCode=" + connection.getResponseCode());
Log.error("post ResponseMessage="
+ connection.getResponseMessage());
reader = new BufferedInputStream(connection.getErrorStream());
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
int b;
byte[] bit = new byte[1024];
while (-1 != (b = reader.read(bit))) {
byteArrayOutputStream.write(bit, 0, b);
}
result = new String(byteArrayOutputStream.toByteArray());
throw new Exception("服务端发生异常");
}
} catch (Exception e) {
e.printStackTrace();
throw e;
} finally {
if (out != null) {
out.flush();
out.close();
}
if (reader != null) {
reader.close();
}
if (connection != null) {
connection.disconnect();
}
}
return result;
}

}