java 通过 HttpURLConnection 上传文件

摘要：直接用的上传文件，通过模拟提交方法具体代码如下网络访问工具默认默认或执行调用地址方法地址请求的与实体对应的信息如执行调用地址方法地址秒连接分钟读数据上传文件表单参数文件参数上传文件允许同一个属性上传多个文件表单参数文件参数调

直接用jdk的HttpURLConnection上传文件，通过模拟post提交方法

具体代码如下：

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Objects;

import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;

/**
 * http 网络访问工具
 *
 * @author wonderful.
 * @version 3.0.0
 */
public class HttpClient {

    private final static Logger LOGGER = Logger.getLogger(HttpClient.class);
    private String method = null;
    private String CONTENT_TYPE = null; //默认
    
    /**
     * 默认POST
     *
     * @return String
     */
    public String getMethod() {
        if (method == null) {
            return "POST";
        }
        return method;
    }

    /**
     *  POST 或 GET 
     *
     * @param method .
     */
    public void setMethod(String method) {
        this.method = method;
    }
    
    /**
     * 执行调用 serviceURL地址 方法
     * @param serviceURL webService地址.
     * @param param String.
     * @param ContentType 请求的与实体对应的MIME信息   如：Content-Type: application/x-www-form-urlencoded,application/json,application/xml  
     * @return String.
     */
    public String pub(String serviceURL, String param,String contentType) {
        CONTENT_TYPE = contentType;
        return pub(serviceURL,param);
    }
    /**
     * 执行调用 serviceURL地址 方法
     * @param serviceURL webService地址.
     * @param param String.
     * @return String.
     */
    public String pub(String serviceURL, String param) {
        URL url = null;
        HttpURLConnection connection = null;
        StringBuffer buffer = new StringBuffer();
        LOGGER.info("request:" + serviceURL + "?" + param);
        try {
            url = new URL(serviceURL);
            connection = (HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
            connection.setDoInput(true);
            connection.setUseCaches(false);
            connection.setRequestMethod(getMethod());
            connection.setConnectTimeout(5000);//30秒连接
            connection.setReadTimeout(5*60*1000);//5分钟读数据
            connection.setRequestProperty("Content-Length", param.length() + "");
            if(CONTENT_TYPE != null){
                connection.setRequestProperty("Content-Type", CONTENT_TYPE);
            }           
            
            OutputStream outputStream = connection.getOutputStream();
            outputStream.write(param.getBytes("UTF-8"));

            BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
            String line = "";
            while ((line = reader.readLine()) != null) {
                buffer.append(line);
            }

            reader.close();
        } catch (IOException e) {
            LOGGER.error(e);
        } finally {

            if (connection != null) {
                connection.disconnect();
            }
        }

        LOGGER.info("response:" + buffer.toString());
        return buffer.toString();
    }

    /**
     * 上传文件
     * 
     * @param serviceURL
     * @param textMap
     *            表单参数
     * @param fileMap
     *            文件参数
     * @return
     * @throws IOException
     */
    public static String formUpload(String serviceURL, Map textMap, Map fileMap) throws IOException {
        Map> tempMap = new HashMap<>();
        if (!Objects.isNull(fileMap) && !fileMap.isEmpty()) {
            Iterator> iter = fileMap.entrySet().iterator();
            while (iter.hasNext()) {
                Map.Entry entry = iter.next();
                String inputName = entry.getKey();
                String inputValue = entry.getValue();
                if (StringUtils.isAnyBlank(inputName, inputValue)) {
                    continue;
                }
                LinkedHashSet values = new LinkedHashSet<>();
                values.add(inputValue);
                tempMap.put(inputName, values);
            }
        }
        return formUploadMulti(serviceURL, textMap, tempMap);
    }

    /**
     * 上传文件,允许同一个属性上传多个文件
     * 
     * @param serviceURL
     * @param textMap
     *            表单参数
     * @param fileMap
     *            文件参数
     * @return
     * @throws IOException
     */
    public static String formUploadMulti(String serviceURL, Map textMap, Map> fileMap) throws IOException {
        LOGGER.trace(String.format("调用文件上传，传入参数:serviceURL=%s,textMap=%s,fileMap=%s", serviceURL, textMap, fileMap));
        String res = "";
        HttpURLConnection conn = null;
        OutputStream out = null;
        BufferedReader reader = null;
        String BOUNDARY = "---------------------------" + System.currentTimeMillis(); // boundary就是request头和上传文件内容的分隔符
        try {
            URL url = new URL(serviceURL);
            conn = (HttpURLConnection) url.openConnection();
            conn.setConnectTimeout(5000);// 30秒连接
            conn.setReadTimeout(5 * 60 * 1000);// 5分钟读数据
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setUseCaches(false);
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + BOUNDARY);

            out = new DataOutputStream(conn.getOutputStream());
            // text
            if (!Objects.isNull(textMap) && !textMap.isEmpty()) {
                StringBuffer strBuf = new StringBuffer();
                Iterator> iter = textMap.entrySet().iterator();
                while (iter.hasNext()) {
                    Map.Entry entry = iter.next();
                    String inputName = entry.getKey();
                    String inputValue = entry.getValue();
                    if (StringUtils.isAnyBlank(inputName, inputValue)) {
                        continue;
                    }
                    strBuf.append("
").append("--").append(BOUNDARY).append("
");
                    strBuf.append("Content-Disposition: form-data; name="" + inputName + ""

");
                    strBuf.append(inputValue);
                }
                out.write(strBuf.toString().getBytes());
            }

            // file
            if (!Objects.isNull(fileMap) && !fileMap.isEmpty()) {
                Iterator>> iter = fileMap.entrySet().iterator();
                while (iter.hasNext()) {
                    Entry> entry = iter.next();
                    String inputName = entry.getKey();
                    LinkedHashSet inputValue = entry.getValue();
                    if (StringUtils.isAnyBlank(inputName) || inputValue.isEmpty()) {
                        continue;
                    }
                    for (String filePath : inputValue) {
                        File file = new File(filePath);
                        String filename = file.getName();
                        Path path = Paths.get(filePath);
                        String contentType = Files.probeContentType(path);
                        StringBuffer strBuf = new StringBuffer();
                        strBuf.append("
").append("--").append(BOUNDARY).append("
");
                        strBuf.append("Content-Disposition: form-data; name="" + inputName + ""; filename="" + filename + ""
");
                        strBuf.append("Content-Type:" + contentType + "

");
                        LOGGER.trace(String.format("filename:%s,contentType:%s", filename, contentType));
                        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 = ("
--" + BOUNDARY + "--
").getBytes();
            out.write(endData);
            out.flush();

            // 读取返回数据
            LOGGER.trace(String.format("http 返回状态:ResponseCode=%s,ResponseMessage=%s", conn.getResponseCode(), conn.getResponseMessage()));
            StringBuffer strBuf = new StringBuffer();
            reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String line = null;
            while ((line = reader.readLine()) != null) {
                strBuf.append(line).append("
");
            }
            res = strBuf.toString();
            LOGGER.trace(String.format("http 返回数据:%s", res));
            reader.close();
            reader = null;
        } catch (IOException e) {
            throw e;
        } finally {
            if (!Objects.isNull(out)) {
                out.close();
                out = null;
            }
            if (!Objects.isNull(reader)) {
                reader.close();
                reader = null;
            }
            if (conn != null) {
                conn.disconnect();
                conn = null;
            }
        }
        return res;
    }
}

上面的两个方法有待优化，未处理