java模拟表单上传文件，java通过模拟post方式提交表单实现图片上传功能实例

java模拟表单上传文件，java通过模拟post方式提交表单实现图片上传功能实例
HttpClient 测试类，提供get post方法实例

package com.zdz.httpclient;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import javax.activation.MimetypesFileTypeMap;

/**
 * java通过模拟post方式提交表单实现图片上传功能实例
 * 其他文件类型可以传入 contentType 实现
 * @author zdz8207
 * {@link http://www.cnblogs.com/zdz8207/}
 * @version 1.0
 */
public class HttpUploadFile {

    public static void main(String[] args) {
        testUploadImage();
    }
    
    /**
     * 测试上传png图片
     * 
     */
    public static void testUploadImage(){
        String url = "http://xxx/wnwapi/index.php/Api/Index/testUploadModelBaking";
        String fileName = "e:/chenjichao/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("
").append("--").append(BOUNDARY)
                            .append("
");
                    strBuf.append("Content-Disposition: form-data; name=""
                            + inputName + ""

");
                    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("
").append("--").append(BOUNDARY)
                            .append("
");
                    strBuf.append("Content-Disposition: form-data; name=""
                            + inputName + ""; filename="" + filename
                            + ""
");
                    strBuf.append("Content-Type:" + 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();
            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("
");
            }
            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;
    }
}

HttpClientTest.java

package com.zdz.httpclient;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.NameValuePair;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;

/**
 * HttpClient 测试类，提供get post方法实例
 * @author zdz8207
 *
 */
public class HttpClientTest {
    private static final String URL = "http://www.163.com";
    private static final int PORT = 80;

    public static void main(String[] args) throws Exception {
        //测试get方法
        doGetMethod(URL,PORT);
        //测试post方法
        String posturl = "http://mail.163.com/";
        doPostMethod(posturl,PORT);
    }

    /**
     * http get 方法
     * @param url
     * @param port
     * @throws HttpException
     * @throws IOException
     * @return bodystring
     */
    public static String doGetMethod(String url,int port) throws HttpException, IOException {
        HttpClient client = new HttpClient();
        // 设置代理服务器地址和端口
        client.getHostConfiguration().setHost(url, port);
        // 使用 GET 方法
        GetMethod method = new GetMethod(url);
        //执行请求
        client.executeMethod(method);

        // 打印服务器返回的状态
        System.out.println(method.getStatusLine());
        // 打印返回的信息
//        System.out.println(method.getResponseBodyAsString());
        // response body of large or unknown size. Using getResponseBodyAsStream instead is recommended. 
        InputStream bodystreams = method.getResponseBodyAsStream();
        String body = convertStreamToString(bodystreams);
        System.out.println(body);
        // 释放连接
        method.releaseConnection();
        
        return body;
    }
    
    /**
     * http post 方法
     * @param url
     * @param port
     * @throws HttpException
     * @throws IOException
     * @return bodystring
     */
    public static String doPostMethod(String url,int port) throws HttpException, IOException {
        HttpClient client = new HttpClient();
        // 设置代理服务器地址和端口
        client.getHostConfiguration().setHost(url, port);
        // 使用POST方法
        PostMethod method = new PostMethod(url);
        //设置传递参数
        NameValuePair agent = new NameValuePair("User-Agent","Mozilla/4.0 (compatible; MSIE 8.0; Windows 2000)");
        NameValuePair username = new NameValuePair("email", "xxx@163.com");
        NameValuePair password = new NameValuePair("password", "xxxxxx");
        method.setRequestBody(new NameValuePair[] { agent, username, password });
        //执行请求
        client.executeMethod(method);
//        设置cookies
//        Cookie[] cookies = client.getState().getCookies();
//        client.getState().addCookies(cookies);
        
        // 打印服务器返回的状态
        System.out.println(method.getStatusLine());
        // 打印返回的信息
//        System.out.println(method.getResponseBodyAsString());
        // response body of large or unknown size. Using getResponseBodyAsStream instead is recommended. 
        InputStream bodystreams = method.getResponseBodyAsStream();
        String body = convertStreamToString(bodystreams);
        System.out.println(body);
        // 释放连接
        method.releaseConnection();
        
        return body;
    }
    
    /**
     * 把InputStream 转换成String返回
     * @param is InputStream
     * @return String
     * @throws UnsupportedEncodingException
     */
    public static String convertStreamToString(InputStream is) throws UnsupportedEncodingException {    
//        BufferedReader reader = new BufferedReader(new InputStreamReader(is));//输出的中文乱码
        BufferedReader reader = new BufferedReader(new InputStreamReader(is,"utf8")); //GBK
        StringBuilder sb = new StringBuilder();    
        String line = null;    
        try {    
            while ((line = reader.readLine()) != null) {
                sb.append(line + "
");    
            }    
        } catch (IOException e) {    
            e.printStackTrace();    
        } finally {    
            try {    
                is.close();    
            } catch (IOException e) {    
               e.printStackTrace();    
            }    
        }    
        return sb.toString();    
    }

}

项目实例下载地址（包括对应jar包）

 ps:New text file line delimiter选择不同导致控制台输出编码不同,如下图所示：