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

我会带着你远行 2022-02-03 01:49 467阅读 0赞

客户端测试代码：

package com.xhtt.test;
    
    import org.junit.Test;
    
    import javax.activation.MimetypesFileTypeMap;
    import java.io.*;
    import java.net.HttpURLConnection;
    import java.net.URL;
    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.Map;
    
    /**
     * @author: LKP
     * @date: 2019/5/8
     */
    public class HttpUploadFile {
    
        @Test
        public void testUploadImage(){
            String url = "http://127.0.0.1:9101/fzxy/add_files";
            String fileName = "C:\\Users\\Administrator\\Desktop\\公众号\\16pic_4271323_b.jpg";
            Map<String, String> textMap = new HashMap<String, String>();
            //可以设置多个input的name，value
            //textMap.put("filename", "16pic_4271323_b.jpg");
            //设置file的name，路径
            Map<String, String> fileMap = new HashMap<String, String>();
            fileMap.put("upfile", fileName);
            String contentType = "image/jpg";//image/png
            String ret = formUpload(url, textMap, fileMap,contentType);
            System.out.println(ret);
    
        }
    
        /**
         * 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 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 = "------WebKitFormBoundaryz7IH92tGZK2AHZLq";
            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;
        }
    
    }

HttpClient 测试类Test，提供get post方法实例

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 + "\n");    
                }    
            } catch (IOException e) {    
                e.printStackTrace();    
            } finally {    
                try {    
                    is.close();    
                } catch (IOException e) {    
                   e.printStackTrace();    
                }    
            }    
            return sb.toString();    
        }
    
    }