java发送post请求，使用multipart/form-data的方式传递参数--《优化》
作者：互联网
/**
* 测试上传图片
*
*/
public static void testUploadImage(){
String url = "http://xxxtest/Api/testUploadModelBaking";
String fileName = "e:/username/textures/antimap_0017.png";
Map<String, String> textMap = new HashMap<String, String>();
//可以设置多个input的name，value
textMap.put("name", "testname");
textMap.put("type", "2");
//设置file的name，路径
Map<String, String> fileMap = new HashMap<String, String>();
fileMap.put("upfile", fileName);
String contentType = "";//image/png
String ret = formUpload(url, textMap, fileMap,contentType);
System.out.println(ret);
//{"status":"0","message":"add succeed","baking_url":"group1\/M00\/00\/A8\/CgACJ1Zo-LuAN207AAQA3nlGY5k151.png"}
}
/**
* 上传图片
* @param urlStr
* @param textMap
* @param fileMap
* @param contentType 没有传入文件类型默认采用application/octet-stream
* contentType非空采用filename匹配默认的图片类型
* @return 返回response数据
*/
@SuppressWarnings("rawtypes")
public static String formUpload(String urlStr, Map<String, String> textMap,
Map<String, String> fileMap,String contentType) {
String res = "";
HttpURLConnection conn = null;
// boundary就是request头和上传文件内容的分隔符
String BOUNDARY = "---------------------------123821742118716";
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
if (textMap != null) {
StringBuffer strBuf = new StringBuffer();
Iterator iter = textMap.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry entry = (Map.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
if (fileMap != null) {
Iterator iter = fileMap.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry entry = (Map.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();
//没有传入文件类型，同时根据文件获取不到类型，默认采用application/octet-stream
contentType = new MimetypesFileTypeMap().getContentType(file);
//contentType非空采用filename匹配默认的图片类型
if(!"".equals(contentType)){
if (filename.endsWith(".png")) {
contentType = "image/png";
}else if (filename.endsWith(".jpg") || filename.endsWith(".jpeg") || filename.endsWith(".jpe")) {
contentType = "image/jpeg";
}else if (filename.endsWith(".gif")) {
contentType = "image/gif";
}else if (filename.endsWith(".ico")) {
contentType = "image/image/x-icon";
}
}
if (contentType == null || "".equals(contentType)) {
contentType = "application/octet-stream";
}
StringBuffer strBuf = new StringBuffer();
strBuf.append("\r\n").append("--").append(BOUNDARY).append("\r\n");
strBuf.append("Content-Disposition: form-data; name=\"" + inputName + "\"; filename=\"" + filename + "\"\r\n");
strBuf.append("Content-Type:" + contentType + "\r\n\r\n");
out.write(strBuf.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);
}
in.close();
}
}
byte[] endData = ("\r\n--" + BOUNDARY + "--\r\n").getBytes();
out.write(endData);
out.flush();
out.close();
// 读取返回数据
StringBuffer strBuf = new StringBuffer();
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line = null;
while ((line = reader.readLine()) != null) {
strBuf.append(line).append("\n");
}
res = strBuf.toString();
reader.close();
reader = null;
} catch (Exception e) {
System.out.println("发送POST请求出错。" + urlStr);
e.printStackTrace();
} finally {
if (conn != null) {
conn.disconnect();
conn = null;
}
}
return res;
}
以上是网上可以搜到显示最多的代码：
实际使用中发现有部分接口无法调通，后来发现是在
strBuf.append("\r\n").append("--").append(BOUNDARY).append("\r\n");
多了换行符，应改为：
strBuf.append("--").append(BOUNDARY).append("\r\n");
完整代码如下：
OutputStream out = new DataOutputStream(conn.getOutputStream());
if (fileMap != null) {
String filename = fileMap.get("filename");
String upload = fileMap.get("upload");
StringBuffer strBuf = new StringBuffer();
strBuf.append("--").append(BOUNDARY).append("\r\n");
strBuf.append("Content-Disposition: form-data;name=\"filename\"\r\n\r\n" + filename + "\r\n");
strBuf.append("--").append(BOUNDARY).append("\r\n");
strBuf.append("Content-Disposition: form-data;name=\"upload\";filename=\"" + upload + "\"\r\n");
strBuf.append("\r\n");
// strBuf.append("test:ai\n");
out.write(strBuf.toString().getBytes());
logger.debug(strBuf.toString());
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);
}
in.close();
byte[] endData = ("\r\n--" + BOUNDARY + "--\r\n").getBytes();
out.write(endData);
out.flush();
out.close();
}
// 读取返回数据
StringBuffer strBuf = new StringBuffer();
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line = null;
while ((line = reader.readLine()) != null) {
strBuf.append(line).append("\n");
}
res = strBuf.toString();
reader.close();
reader = null;
logger.info("上传完成:"+res);
这个要根据接收者的接收协议来确定使用哪一种方式。
标签：java,form,strBuf,--,filename,conn,new,append,String 来源： https://www.cnblogs.com/liangblog/p/15223253.html