springMVC 服务器端模拟浏览器发送请求，传递图片与文件到不同的服务器

   /**
    * 模拟请求发送服务器文字和图片
    * @param urlStr
    * @param textMap
    * @param fileMap
    * @return
    */
    public static String formUpload(String urlStr, Map<String, String> textMap,
Map<String, String> fileMap) {
String res = "";
HttpURLConnection conn = null;
String BOUNDARY = "---------------------------123821742118716"; // boundary就是request头和上传文件内容的分隔符
try {
URL url = new URL(urlStr);
conn = (HttpURLConnection) url.openConnection();
conn.setConnectTimeout(5000);
conn.setReadTimeout(30000);
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setUseCaches(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("User-Agent",
"Mozilla/5.0 (Windows; U; Windows NT 6.1; zh-CN; rv:1.9.2.6)");
conn.setRequestProperty("Content-Type",
"multipart/form-data; boundary=" + BOUNDARY);

OutputStream out = new DataOutputStream(conn.getOutputStream());
// text 文字传递
if (textMap != null) {

StringBuffer strBuf = new StringBuffer();
Iterator<Entry<String, String>> iter = textMap.entrySet().iterator();
while (iter.hasNext()) {
Entry<String, String> entry =  iter.next();
String inputName = (String) entry.getKey();
String inputValue = (String) entry.getValue();
if (inputValue == null) {
continue;
}
strBuf.append("\r\n").append("--").append(BOUNDARY)
.append("\r\n");
strBuf.append("Content-Disposition: form-data; name=\""
+ inputName + "\"\r\n\r\n");
strBuf.append(inputValue);
}
out.write(strBuf.toString().getBytes());
}

// file 图片传递
if (fileMap != null) {
Iterator<Entry<String, String>> iter = fileMap.entrySet().iterator();
while (iter.hasNext()) {
Entry<String, String> entry =  iter.next();
String inputName = (String) entry.getKey();
String inputValue = (String) entry.getValue();
if (inputValue == null) {
continue;
}
File file = new File(inputValue);
String filename = file.getName();