JAVA通过HttpURLConnection 上传和下载文件的方法

package com.util;import java.io.BufferedInputStream;import java.io.BufferedReader;import java.io.DataOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.OutputStreamWriter;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import java.net.URLConnection;import java.util.Iterator;import java.util.Map;/** * Java原生的API可用于发送HTTP请求，即java.net.URL、java.net.URLConnection，这些API很好用、很常用， * 但不够简便； *  * 1.通过统一资源定位器（java.net.URL）获取连接器（java.net.URLConnection） 2.设置请求的参数 3.发送请求 * 4.以输入流的形式获取返回内容 5.关闭输入流 *  * @author H__D * */public class HttpConnectionUtil { /**  * 多文件上传的方法  *   * @param actionUrl：上传的路径  * @param uploadFilePaths：需要上传的文件路径，数组  * @return  */ @SuppressWarnings("finally") public static String uploadFile(String actionUrl, String[] uploadFilePaths) {  String end = "/r/n";  String twoHyphens = "--";  String boundary = "*****";  DataOutputStream ds = null;  InputStream inputStream = null;  InputStreamReader inputStreamReader = null;  BufferedReader reader = null;  StringBuffer resultBuffer = new StringBuffer();  String tempLine = null;  try {   // 统一资源   URL url = new URL(actionUrl);   // 连接类的父类，抽象类   URLConnection urlConnection = url.openConnection();   // http的连接类   HttpURLConnection httpURLConnection = (HttpURLConnection) urlConnection;   // 设置是否从httpUrlConnection读入，默认情况下是true;   httpURLConnection.setDoInput(true);   // 设置是否向httpUrlConnection输出   httpURLConnection.setDoOutput(true);   // Post 请求不能使用缓存   httpURLConnection.setUseCaches(false);   // 设定请求的方法，默认是GET   httpURLConnection.setRequestMethod("POST");   // 设置字符编码连接参数   httpURLConnection.setRequestProperty("Connection", "Keep-Alive");   // 设置字符编码   httpURLConnection.setRequestProperty("Charset", "UTF-8");   // 设置请求内容类型   httpURLConnection.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);   // 设置DataOutputStream   ds = new DataOutputStream(httpURLConnection.getOutputStream());   for (int i = 0; i < uploadFilePaths.length; i++) {    String uploadFile = uploadFilePaths[i];    String filename = uploadFile.substring(uploadFile.lastIndexOf("//") + 1);    ds.writeBytes(twoHyphens + boundary + end);    ds.writeBytes("Content-Disposition: form-data; " + "name=/"file" + i + "/";filename=/"" + filename      + "/"" + end);    ds.writeBytes(end);    FileInputStream fStream = new FileInputStream(uploadFile);    int bufferSize = 1024;    byte[] buffer = new byte[bufferSize];    int length = -1;    while ((length = fStream.read(buffer)) != -1) {     ds.write(buffer, 0, length);    }    ds.writeBytes(end);    /* close streams */    fStream.close();   }   ds.writeBytes(twoHyphens + boundary + twoHyphens + end);   /* close streams */   ds.flush();   if (httpURLConnection.getResponseCode() >= 300) {    throw new Exception(      "HTTP Request is not success, Response code is " + httpURLConnection.getResponseCode());   }   if (httpURLConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {    inputStream = httpURLConnection.getInputStream();    inputStreamReader = new InputStreamReader(inputStream);    reader = new BufferedReader(inputStreamReader);    tempLine = null;    resultBuffer = new StringBuffer();    while ((tempLine = reader.readLine()) != null) {     resultBuffer.append(tempLine);     resultBuffer.append("/n");    }   }  } catch (Exception e) {   // TODO Auto-generated catch block   e.printStackTrace();  } finally {   if (ds != null) {    try {     ds.close();    } catch (IOException e) {     // TODO Auto-generated catch block     e.printStackTrace();    }   }   if (reader != null) {    try {     reader.close();    } catch (IOException e) {     // TODO Auto-generated catch block     e.printStackTrace();    }   }   if (inputStreamReader != null) {    try {     inputStreamReader.close();    } catch (IOException e) {     // TODO Auto-generated catch block     e.printStackTrace();    }   }   if (inputStream != null) {    try {     inputStream.close();    } catch (IOException e) {     // TODO Auto-generated catch block     e.printStackTrace();    }   }   return resultBuffer.toString();  } } public static void main(String[] args) {  // 上传文件测试   String str = uploadFile("http://127.0.0.1:8080/image/image.do",new String[] { "/Users//H__D/Desktop//1.png","//Users/H__D/Desktop/2.png" });   System.out.println(str); }}

package com.util;import java.io.BufferedInputStream;import java.io.BufferedReader;import java.io.DataOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.OutputStreamWriter;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import java.net.URLConnection;import java.util.Iterator;import java.util.Map;/** * Java原生的API可用于发送HTTP请求，即java.net.URL、java.net.URLConnection，这些API很好用、很常用， * 但不够简便； *  * 1.通过统一资源定位器（java.net.URL）获取连接器（java.net.URLConnection） 2.设置请求的参数 3.发送请求 * 4.以输入流的形式获取返回内容 5.关闭输入流 *  * @author H__D * */public class HttpConnectionUtil { /**  *   * @param urlPath  *   下载路径  * @param downloadDir  *   下载存放目录  * @return 返回下载文件  */ public static File downloadFile(String urlPath, String downloadDir) {  File file = null;  try {   // 统一资源   URL url = new URL(urlPath);   // 连接类的父类，抽象类   URLConnection urlConnection = url.openConnection();   // http的连接类   HttpURLConnection httpURLConnection = (HttpURLConnection) urlConnection;   // 设定请求的方法，默认是GET   httpURLConnection.setRequestMethod("POST");   // 设置字符编码   httpURLConnection.setRequestProperty("Charset", "UTF-8");   // 打开到此 URL 引用的资源的通信链接（如果尚未建立这样的连接）。   httpURLConnection.connect();   // 文件大小   int fileLength = httpURLConnection.getContentLength();   // 文件名   String filePathUrl = httpURLConnection.getURL().getFile();   String fileFullName = filePathUrl.substring(filePathUrl.lastIndexOf(File.separatorChar) + 1);   System.out.println("file length---->" + fileLength);   URLConnection con = url.openConnection();   BufferedInputStream bin = new BufferedInputStream(httpURLConnection.getInputStream());   String path = downloadDir + File.separatorChar + fileFullName;   file = new File(path);   if (!file.getParentFile().exists()) {    file.getParentFile().mkdirs();   }   OutputStream out = new FileOutputStream(file);   int size = 0;   int len = 0;   byte[] buf = new byte[1024];   while ((size = bin.read(buf)) != -1) {    len += size;    out.write(buf, 0, size);    // 打印下载百分比    // System.out.println("下载了-------> " + len * 100 / fileLength +    // "%/n");   }   bin.close();   out.close();  } catch (MalformedURLException e) {   // TODO Auto-generated catch block   e.printStackTrace();  } catch (IOException e) {   // TODO Auto-generated catch block   e.printStackTrace();  } finally {   return file;  } } public static void main(String[] args) {  // 下载文件测试  downloadFile("http://localhost:8080/images/1467523487190.png", "/Users/H__D/Desktop"); }}