HttpURLConnection发送POST请求（可包含文件）

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;

/**
 * HttpURLConnection发送Post请求工具类
 *
 * @author pang
 *
 */
public class HttpURLConnectionPost {

    /**
     * 通过拼接的方式构造请求内容，实现参数传输以及文件传输
     *
     * @param actionUrl
     *            访问的服务器URL
     * @param params
     *            普通参数
     * @param files
     *            文件参数
     * @return
     * @throws IOException
     */
    public static String post(String actionUrl, Map<String, String> params,
            Map<String, File> files) throws Exception {

        StringBuilder sb2 = new StringBuilder();
        String BOUNDARY = java.util.UUID.randomUUID().toString();
        String PREFIX = "--", LINEND = "\r\n";
        String MULTIPART_FROM_DATA = "multipart/form-data";
        String CHARSET = "UTF-8";

        URL uri = new URL(actionUrl);
        HttpURLConnection conn = (HttpURLConnection) uri.openConnection();
        conn.setReadTimeout(5 * 1000); // 缓存的最长时间
        conn.setDoInput(true);// 允许输入
        conn.setDoOutput(true);// 允许输出
        conn.setUseCaches(false); // 不允许使用缓存
        conn.setRequestMethod("POST");
        conn.setRequestProperty("connection", "keep-alive");
        conn.setRequestProperty("Charsert", "UTF-8");
        conn.setRequestProperty("Content-Type", MULTIPART_FROM_DATA
                + ";boundary=" + BOUNDARY);

        // 首先组拼文本类型的参数
        StringBuilder sb = new StringBuilder();
        for (Map.Entry<String, String> entry : params.entrySet()) {
            sb.append(PREFIX);
            sb.append(BOUNDARY);
            sb.append(LINEND);
            sb.append("Content-Disposition: form-data; name=\""
                    + entry.getKey() + "\"" + LINEND);
            sb.append("Content-Type: text/plain; charset=" + CHARSET + LINEND);
            sb.append("Content-Transfer-Encoding: 8bit" + LINEND);
            sb.append(LINEND);
            sb.append(entry.getValue());
            sb.append(LINEND);
        }

        DataOutputStream outStream = new DataOutputStream(
                conn.getOutputStream());
        outStream.write(sb.toString().getBytes());
        InputStream in = null;
        // 发送文件数据
        if (files != null) {
            for (Map.Entry<String, File> file : files.entrySet()) {
                StringBuilder sb1 = new StringBuilder();
                sb1.append(PREFIX);
                sb1.append(BOUNDARY);
                sb1.append(LINEND);
                // name是post中传参的键 filename是文件的名称
                sb1.append("Content-Disposition: form-data; name=\"file\"; filename=\""
                        + file.getKey() + "\"" + LINEND);
                sb1.append("Content-Type: application/octet-stream; charset="
                        + CHARSET + LINEND);
                sb1.append(LINEND);
                outStream.write(sb1.toString().getBytes());

                InputStream is = new FileInputStream(file.getValue());
                byte[] buffer = new byte[1024];
                int len = 0;
                while ((len = is.read(buffer)) != -1) {
                    outStream.write(buffer, 0, len);
                }

                is.close();
                outStream.write(LINEND.getBytes());
            }

        }
        // 请求结束标志
        byte[] end_data = (PREFIX + BOUNDARY + PREFIX + LINEND).getBytes();
        outStream.write(end_data);
        outStream.flush();
        // 得到响应码
        int res = conn.getResponseCode();
        if (res == 200) {
            // 读取返回数据
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    conn.getInputStream(), "UTF-8")); //$NON-NLS-1$
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb2.append(line).append("\n"); //$NON-NLS-1$
            }
            reader.close();
        }
        outStream.close();
        conn.disconnect();

        return sb2.toString();
    }

    /**
     * 以数据流的形式传参
     *
     * @param actionUrl
     * @param params
     * @param files
     * @return
     * @throws Exception
     */
    public static String postFile(String actionUrl, Map<String, String> params,
            Map<String, byte[]> files) throws Exception {
        StringBuilder sb2 = new StringBuilder();
        String BOUNDARY = java.util.UUID.randomUUID().toString();
        String PREFIX = "--", LINEND = "\r\n";
        String MULTIPART_FROM_DATA = "multipart/form-data";
        String CHARSET = "UTF-8";

        URL uri = new URL(actionUrl);
        HttpURLConnection conn = (HttpURLConnection) uri.openConnection();
        conn.setReadTimeout(6 * 1000); // 缓存的最长时间
        conn.setDoInput(true);// 允许输入
        conn.setDoOutput(true);// 允许输出
        conn.setUseCaches(false); // 不允许使用缓存
        conn.setRequestMethod("POST");
        conn.setRequestProperty("connection", "keep-alive");
        conn.setRequestProperty("Charsert", "UTF-8");
        conn.setRequestProperty("Content-Type", MULTIPART_FROM_DATA
                + ";boundary=" + BOUNDARY);

        // 首先组拼文本类型的参数
        StringBuilder sb = new StringBuilder();
        for (Map.Entry<String, String> entry : params.entrySet()) {
            sb.append(PREFIX);
            sb.append(BOUNDARY);
            sb.append(LINEND);
            sb.append("Content-Disposition: form-data; name=\""
                    + entry.getKey() + "\"" + LINEND);
            sb.append("Content-Type: text/plain; charset=" + CHARSET + LINEND);
            sb.append("Content-Transfer-Encoding: 8bit" + LINEND);
            sb.append(LINEND);
            sb.append(entry.getValue());
            sb.append(LINEND);
        }

        DataOutputStream outStream = new DataOutputStream(
                conn.getOutputStream());
        outStream.write(sb.toString().getBytes());
        InputStream in = null;
        // 发送文件数据
        if (files != null) {
            for (Map.Entry<String, byte[]> file : files.entrySet()) {
                StringBuilder sb1 = new StringBuilder();
                sb1.append(PREFIX);
                sb1.append(BOUNDARY);
                sb1.append(LINEND);

                sb1.append("Content-Disposition: form-data; name=\"file\"; filename=\"" //$NON-NLS-1$
                        + file.getKey() + "\"" + LINEND);
                sb1.append("Content-Type:" + "application/octet-stream;UTF-8"
                        + LINEND);
                sb1.append(LINEND);
                outStream.write(sb1.toString().getBytes());

                outStream.write(file.getValue());

                outStream.write(LINEND.getBytes());
            }

        }
        // 请求结束标志
        byte[] end_data = (PREFIX + BOUNDARY + PREFIX + LINEND).getBytes();
        outStream.write(end_data);
        outStream.flush();
        // 得到响应码
        int res = conn.getResponseCode();
        if (res == 200) {
            // 读取返回数据
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    conn.getInputStream(), "UTF-8")); //$NON-NLS-1$
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb2.append(line).append("\n"); //$NON-NLS-1$
            }
            reader.close();
        }
        outStream.close();
        conn.disconnect();

        return sb2.toString();
    }

    public static byte[] getContent(String filePath) throws IOException {
        File file = new File(filePath);
        long fileSize = file.length();
        if (fileSize > Integer.MAX_VALUE) {
            System.out.println("file too big...");
            return null;
        }
        FileInputStream fi = new FileInputStream(file);
        byte[] buffer = new byte[(int) fileSize];
        int offset = 0;
        int numRead = 0;
        while (offset < buffer.length
                && (numRead = fi.read(buffer, offset, buffer.length - offset)) >= 0) {
            offset += numRead;
        }
        // 确保所有数据均被读取
        if (offset != buffer.length) {
            throw new IOException("Could not completely read file "
                    + file.getName());
        }
        fi.close();
        return buffer;
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        String Default_Address = "http://192.168.21.106:8080/ideweb/noSessionAndSecurity_submitBug.do";
        try {
            Map<String, String> requestParamsMap = new HashMap<String, String>();
            requestParamsMap.put("userName", "huadoumi");
            requestParamsMap.put("desp",
                    "<h1>123&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;321</h1>");
            requestParamsMap.put("fileName", "zzz.txt");
            requestParamsMap.put("productId", "AFAIDE");

            // Map<String, byte[]> files = new HashMap<String, byte[]>();
            // byte[] bytes = getContent("E:" + File.separator + "hello.txt");
            // files.put("zzz.txt", bytes);
            // String a = postFile(Default_Address, requestParamsMap, files);
            // System.out.println(a);

            Map<String, File> files = new HashMap<String, File>();
            File file = new File("E:" + File.separator + "hello.txt");
            files.put("aaa.txt", file);
            String b = post(Default_Address, requestParamsMap, files);
            System.out.println(b);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}