使用java代码提交图片到服务器

import java.io.IOException;
import java.net.*;
import java.io.*;
import java.util.*;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.imageio.*;
import javax.imageio.stream.*;

/**
*
* @author zcwangjb
*/
public class HttpPostUtil {

URL url;
HttpURLConnection conn;
String boundary = "--------httppost123";
Map<String, String> textParams = new HashMap<String, String>();
Map<String, File> fileparams = new HashMap<String, File>();
DataOutputStream ds;

public HttpPostUtil() {

}

public HttpPostUtil(String url) throws Exception {
this.url = new URL(url);
}

//重新设置要请求的服务器地址，即上传文件的地址。
public void setUrl(String url) throws Exception {
this.url = new URL(url);
}

//增加一个普通字符串数据到form表单数据中
public void addTextParameter(String name, String value) {
textParams.put(name, value);
}

//增加一个文件到form表单数据中
public void addFileParameter(String name, File value) {
fileparams.put(name, value);
}

// 清空所有已添加的form表单数据
public void clearAllParameters() {
textParams.clear();
fileparams.clear();
}

// 发送数据到服务器，返回一个字节包含服务器的返回结果的数组
public byte[] send() throws Exception {
initConnection();
try {
conn.connect();
} catch (SocketTimeoutException e) {
// something
throw new RuntimeException();
}
ds = new DataOutputStream(conn.getOutputStream());
writeFileParams();
writeStringParams();
paramsEnd();
InputStream in = conn.getInputStream();
ByteArrayOutputStream out = new ByteArrayOutputStream();
int b;
while ((b = in.read()) != -1) {
out.write(b);
}
conn.disconnect();
return out.toByteArray();
}

//文件上传的connection的一些必须设置
private void initConnection() throws Exception {
conn = (HttpURLConnection) this.url.openConnection();
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setConnectTimeout(10000); //连接超时为10秒
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type",
"multipart/form-data; boundary=" + boundary);
}

//普通字符串数据
private void writeStringParams() throws Exception {
Set<String> keySet = textParams.keySet();
for (Iterator<String> it = keySet.iterator(); it.hasNext();) {
String name = it.next();
String value = textParams.get(name);
ds.writeBytes("--" + boundary + "\r\n");
ds.writeBytes("Content-Disposition: form-data; name=\"" + name
+ "\"\r\n");
ds.writeBytes("\r\n");
ds.writeBytes(encode(value) + "\r\n");
}
}

//文件数据
private void writeFileParams() throws Exception {
Set<String> keySet = fileparams.keySet();
for (Iterator<String> it = keySet.iterator(); it.hasNext();) {
String name = it.next();
File value = fileparams.get(name);
ds.writeBytes("--" + boundary + "\r\n");
ds.writeBytes("Content-Disposition: form-data; name=\"" + name
+ "\"; filename=\"" + encode(value.getName()) + "\"\r\n");
ds.writeBytes("Content-Type: " + getContentType(value) + "\r\n");
ds.writeBytes("\r\n");
ds.write(getBytes(value));
ds.writeBytes("\r\n");
}
}

//获取文件的上传类型，图片格式为image/png,image/jpg等。非图片为application/octet-stream
private String getContentType(File f) throws Exception {

//      return "application/octet-stream";  // 此行不再细分是否为图片，全部作为application/octet-stream 类型
ImageInputStream imagein = ImageIO.createImageInputStream(f);
if (imagein == null) {
return "application/octet-stream";
}
Iterator<ImageReader> it = ImageIO.getImageReaders(imagein);
if (!it.hasNext()) {
imagein.close();
return "application/octet-stream";
}
imagein.close();
return "image/" + it.next().getFormatName().toLowerCase();//将FormatName返回的值转换成小写，默认为大写

}

//把文件转换成字节数组
private byte[] getBytes(File f) throws Exception {
FileInputStream in = new FileInputStream(f);
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] b = new byte[1024];
int n;
while ((n = in.read(b)) != -1) {
out.write(b, 0, n);
}
in.close();
return out.toByteArray();
}

//添加结尾数据
private void paramsEnd() throws Exception {
ds.writeBytes("--" + boundary + "--" + "\r\n");
ds.writeBytes("\r\n");
}

// 对包含中文的字符串进行转码，此为UTF-8。服务器那边要进行一次解码
private String encode(String value) throws Exception {
return URLEncoder.encode(value, "UTF-8");
}

public String detectImg(String url) {
try {
HttpPostUtil u = new HttpPostUtil("");
u.addFileParameter("image", new File(url));
//  u.addTextParameter("text", "中文");
byte[] b = u.send();
String result = new String(b);
System.out.println(result);
return result;
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}

public static void main(String[] args) throws Exception {
HttpPostUtil u = new HttpPostUtil("");
u.addFileParameter("image", new File(""));
byte[] b = u.send();
String result = new String(b);
System.out.println(result);

}

public void sendImgbyPost(String url, String postcontent) throws IOException {
try {
HttpURLConnection huc = (HttpURLConnection) new URL(url).openConnection();
huc.setDoInput(true);
huc.setDoOutput(true);
huc.setRequestMethod("POST");

PrintWriter pw = new PrintWriter(new OutputStreamWriter(huc.getOutputStream()));
pw.print(postcontent);
pw.close();

BufferedReader br = new BufferedReader(new InputStreamReader(huc.getInputStream()));
String content = "";
String line = br.readLine();
while (line != null) {
content = content + line;
line = br.readLine();

}

} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

}