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在开发中,经常会遇到调用其它系统接口传数据的功能,一般都是穿文本数据,但是偶尔也会有传递附件的接口和普通文本的.

第一种,使用HttpURLConnection

package DownTest;import java.io.BufferedReader;import java.io.ByteArrayOutputStream;import java.io.DataInputStream;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.io.OutputStream;import java.net.HttpURLConnection;import java.net.URL;import java.util.HashMap;import javax.activation.MimetypesFileTypeMap;import org.apache.http.entity.mime.MultipartEntityBuilder;public class FileToInterfaceTest01 {   	public void formUpload(HashMap
   
     params) {   			String urlStr = "";				String res = "";		String wf_docnumber="普通文本字段";		String LinkmanEmail="普通文本字段2";		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			StringBuffer strBuf = new StringBuffer();			strBuf.append("\r\n").append("--").append(BOUNDARY).append("\r\n");			strBuf.append("Content-Disposition:form-data;name=\"wf_docnumber\"\r\n\r\n");			strBuf.append(wf_docnumber);			strBuf.append("\r\n").append("--").append(BOUNDARY).append("\r\n");			strBuf.append("Content-Disposition:form-data;name=\"LinkmanEmail\"\r\n\r\n");			strBuf.append(LinkmanEmail);			out.write(strBuf.toString().getBytes());// file			String filePath = "";			MultipartEntityBuilder reqEntity = MultipartEntityBuilder.create();			// ContentType contentType = ContentType.create("text/plain",			// Charset.forName("UTF-8"));			// ContentType contentType = ContentType.create(HTTP.PLAIN_TEXT_TYPE,			// HTTP.UTF_8);								/* 读取文件 */					File file = new File(filePath);					// file.name					String filename="";					/* 如果文件存在 */					if (file.exists()) {   												String contentType = new MimetypesFileTypeMap().getContentType(file);						contentType = "application/octet-stream";						// contentType="application/x-www-form-urlencoded";						StringBuffer strBuf2 = new StringBuffer();						strBuf2.append("\r\n").append("--").append(BOUNDARY).append("\r\n");						strBuf2.append("Content-Disposition:form-data;name=\"items\";filename=\"" + filename								+ "\"\r\n");						strBuf2.append("Content-Type:" + contentType + "\r\n\r\n");						out.write(strBuf2.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();					} else {   						System.out.println("Error: can't find the file " + filename);					}										byte[] endData = ("\r\n--" + BOUNDARY + "--\r\n").getBytes();			out.write(endData);			out.flush();			out.close();// 读取返回数据			StringBuffer strBuf3 = new StringBuffer();			InputStream inputStream = conn.getInputStream();			BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));			String line = null;			while ((line = reader.readLine()) != null) {   				strBuf3.append(line).append("\n");			}			res = strBuf3.toString();			reader.close();			reader = null;		} catch (Exception e) {   			System.out.println("发送POST请求出错。e=" + e);						InputStream inputStream = conn.getErrorStream();			ByteArrayOutputStream baos = new ByteArrayOutputStream();// 自带缓存的输出流			String str = "";			/// String str2="";			int len = -1;			byte[] buffer = new byte[1024];			try {   				while ((len = inputStream.read(buffer)) != -1) {   					baos.write(buffer, 0, len); // 将读到的字节，写入baos					// str2+=new String(buffer);				}				str = new String(baos.toByteArray(), "utf-8");				System.out.println(str);			} catch (IOException e1) {   				e.printStackTrace();			}			e.printStackTrace();		} finally {   			if (conn != null) {   				conn.disconnect();				conn = null;			}		}		System.out.println(res);	}}
   

第一种写起来太麻烦,使用HttpClient要方便多了

package DownTest;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.InputStream;import java.nio.charset.Charset;import org.apache.http.HttpEntity;import org.apache.http.client.methods.CloseableHttpResponse;import org.apache.http.client.methods.HttpPost;import org.apache.http.conn.ssl.SSLConnectionSocketFactory;import org.apache.http.conn.ssl.SSLContextBuilder;import org.apache.http.conn.ssl.TrustSelfSignedStrategy;import org.apache.http.entity.ContentType;import org.apache.http.entity.mime.HttpMultipartMode;import org.apache.http.entity.mime.MultipartEntityBuilder;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.util.EntityUtils;/** * java传递附件给接口 *  * */public class FileToInterfaceTest02 {   	public void send() throws Exception {   		String url = "";		String res = "";		String wf_docnumber = "普通文本字段";		String LinkmanEmail = "普通文本字段2";		MultipartEntityBuilder fileList = getAttachmentsNameAndPath();		fileList.setCharset(java.nio.charset.Charset.forName("UTF-8"));		fileList.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);		// BeanCtx.p(fileList);			fileList.addTextBody("receiverMails", LinkmanEmail, ContentType.MULTIPART_FORM_DATA);		fileList.addTextBody("wf_docnumber", wf_docnumber, ContentType.MULTIPART_FORM_DATA);		SSLContextBuilder builder = new SSLContextBuilder();		builder.loadTrustMaterial(null, new TrustSelfSignedStrategy());		SSLConnectionSocketFactory sslFactory = new SSLConnectionSocketFactory(builder.build());		CloseableHttpClient http = HttpClients.custom().setSSLSocketFactory(sslFactory).build();		String list = postSend(fileList, url, http);		System.out.println(list);	}	public MultipartEntityBuilder getAttachmentsNameAndPath() throws Exception {   		MultipartEntityBuilder reqEntity = MultipartEntityBuilder.create();		ContentType contentType = ContentType.create("text/plain", Charset.forName("UTF-8"));		// ContentType contentType = ContentType.create(HTTP.PLAIN_TEXT_TYPE,		// HTTP.UTF_8);		String filePath = "";		/* 读取文件 */		File file = new File(filePath);		// file.name		/* 如果文件存在 */		if (file.exists()) {   			int fileLength = (int) file.length();			/* 如果文件长度大于0 */			if (fileLength != 0) {   				/* 创建输入流 */				InputStream inStream = new FileInputStream(file);				byte[] buf = new byte[4096];				/* 创建输出流gjjj */				ByteArrayOutputStream bos = new ByteArrayOutputStream(1024);				byte[] b = new byte[1000];				int readLength;				while (((readLength = inStream.read(buf)) != -1)) {   					bos.write(buf, 0, readLength);				}				inStream.close();				byte[] data = bos.toByteArray();				bos.close();				// application/x-www-form-urlencoded。				reqEntity.addBinaryBody("file", data, ContentType.MULTIPART_FORM_DATA, file.getName());				// StringBody stringBody = new				// StringBody(doc.g("WF_OrUnid")+":"+downloadfilename, contentType);				// reqEntity.addPart("fileName", stringBody);				// fileList.add(map);			}		}		// return fileList;		return reqEntity;	}	public String postSend(MultipartEntityBuilder map, String url, CloseableHttpClient http) throws Exception {   		// System.out.println("url="+url);		String body = "";		String encoding = "utf-8";			HttpPost httpPost = new HttpPost(url);			httpPost.setEntity(map.build());				httpPost.setHeader("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");				// 执行请求操作，并拿到结果（同步阻塞）		CloseableHttpResponse response = http.execute(httpPost);		// 获取结果实体		HttpEntity entity = response.getEntity();		if (entity != null) {   			// 按指定编码转换结果实体为String类型			body = EntityUtils.toString(entity, encoding);		}		response.close();		return body;	}}

上面两种虽然写法不同,但是其实是一样,都是模拟前端表单上传附件的形式,接口接收时是接收对应的io流.

package DownTest;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStream;import java.nio.charset.Charset;import java.util.ArrayList;import java.util.Base64;import java.util.HashMap;import java.util.List;import java.util.Map;import org.apache.http.HttpEntity;import org.apache.http.NameValuePair;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.CloseableHttpResponse;import org.apache.http.client.methods.HttpPost;import org.apache.http.conn.ssl.SSLConnectionSocketFactory;import org.apache.http.conn.ssl.SSLContextBuilder;import org.apache.http.conn.ssl.TrustSelfSignedStrategy;import org.apache.http.entity.StringEntity;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.message.BasicNameValuePair;import org.apache.http.protocol.HTTP;import org.apache.http.util.EntityUtils;import com.alibaba.fastjson.JSONArray;/** * java传递附件给接口 *  * */public class FileToInterfaceTest03 {   	public void send() throws Exception {   		String url = "";		String res = "";		String wf_docnumber = "普通文本字段";		String LinkmanEmail = "普通文本字段2";		List