java 文件断点续下载源码及实例 支持Etag HTTP认证用户名密码

package com.leizhu; import org.apache.http.Header; import org.apache.http.HttpEntity; import org.apache.http.auth.AuthScope; import org.apache.http.auth.UsernamePasswordCredentials; import org.apache.http.client.CredentialsProvider; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.utils.URIBuilder; import org.apache.http.impl.client.BasicCredentialsProvider; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClients; import java.io.*; import java.net.URISyntaxException; import java.nio.file.CopyOption; import java.nio.file.Files; import java.nio.file.Paths; import java.nio.file.StandardCopyOption; import java.util.*; /** * Created by 01312170 on 14-12-24. */ public class HttpClientUtils { private static int BUF = 4096; private static int FILE_BUF = 1024 * 1024; /** * 下载 * @param fileUrl 文件HTTP地址 * @param localPath 文件本地路径 * @param tempLocalPath 文件本地临时路径 * @param isReload 是否需要重新下载 * @param authorUserName 认证用户名 * @param authorUserName 认证密码 * @return * @throws IOException * @throws URISyntaxException */ public static boolean downloadFile(String fileUrl, String localPath, String tempLocalPath, String authorUserName, String authorPassword, boolean isReload) throws Exception { Map<String, Long> params = new HashMap<String, Long>(); boolean result = true; // 获取服务器上文件大小 long fileSize = getFileSize(fileUrl , authorUserName, authorPassword); params.put("fileSize", fileSize); params.put("currentSize", 0L); // 实际大小小于等于0，无需下载 if (fileSize <= 0) { //return params; return false; } // 本地大小与实际大小不同，需要重新下载 long localSize = 0; File file = new File(localPath); if (!(file.getParentFile().exists() && file.getParentFile().isDirectory())) { file.getParentFile().mkdirs(); } File tempFile = new File(tempLocalPath); if (!(tempFile.getParentFile().exists() && tempFile.getParentFile().isDirectory())) { tempFile.getParentFile().mkdirs(); } String fileEtag = getFileEtag(fileUrl , authorUserName, authorPassword); String etagFilePath = ""; if(fileEtag != null){ etagFilePath = tempFile.getParentFile().getPath().concat(File.separator).concat(tempFile.getName()).concat("_etag.txt"); if(new File(etagFilePath).exists()){ String oldFileEtag = readFileContent(etagFilePath); if(oldFileEtag == null){ System.out.println("==========读取文件失败============"); return false; } if(!fileEtag.equals(oldFileEtag)){ isReload = true; //写入新的etag if(!writeFileContent(etagFilePath, fileEtag)){ System.out.println("==========写入文件失败============"); return false; }; }else{ //临时目录不存在，目标目录存在，且目标目录文件大小和线上大小相同则不需要下载，直接返回下载成功 if(!tempFile.exists() && file.exists() && file.length() == fileSize){ return true; } } }else{ if(!writeFileContent(etagFilePath, fileEtag)){ System.out.println("==========写入文件失败============"); return false; }; } } // 检测是否支持断点下载 if (checkRange(fileUrl, authorUserName, authorPassword)) { if(tempFile.exists()){ if(tempFile.length() == fileSize){ moveFile(tempFile.getAbsolutePath(), file.getAbsolutePath()); return true; } } //支持分段 RandomAccessFile tempLocalFile = new RandomAccessFile(tempLocalPath, "rw"); localSize = tempLocalFile.length(); if (localSize > fileSize || isReload) { localSize = 0; tempLocalFile.setLength(0); } CloseableHttpResponse response = null; try { URIBuilder uriBuilder = new URIBuilder(fileUrl); CloseableHttpClient httpClient; if(null != authorUserName && null != authorPassword){ CredentialsProvider provider = new BasicCredentialsProvider(); UsernamePasswordCredentials credentials = new UsernamePasswordCredentials(authorUserName, authorPassword); provider.setCredentials(AuthScope.ANY, credentials); httpClient = HttpClients.custom().setDefaultCredentialsProvider(provider).build(); }else{ httpClient = HttpClients.createDefault(); } HttpGet httpGet = new HttpGet(uriBuilder.build()); httpGet.addHeader("Range", "bytes=" + localSize + "-"); response = httpClient.execute(httpGet); HttpEntity entity = response.getEntity(); if (entity != null) { InputStream instream = entity.getContent(); try { byte[] _r = new byte[FILE_BUF]; int length; while ((length = instream.read(_r)) != -1) { tempLocalFile.seek(localSize); tempLocalFile.write(_r, 0, length); localSize = localSize + length; } } catch (Exception e) { result = false; e.printStackTrace(); throw new Exception(); } finally { instream.close(); } } }catch (Exception e){ result = false; e.printStackTrace(); throw new Exception(); }finally { if(response != null){ response.close(); } if(tempLocalFile != null){ tempLocalFile.close(); } } } else { //不支持分段 RandomAccessFile tempLocalFile = new RandomAccessFile(tempLocalPath, "rw"); localSize = 0; CloseableHttpResponse response = null; try { URIBuilder uriBuilder = new URIBuilder(fileUrl); CloseableHttpClient httpClient; if(null != authorUserName && null != authorPassword){ CredentialsProvider provider = new BasicCredentialsProvider(); UsernamePasswordCredentials credentials = new UsernamePasswordCredentials(authorUserName, authorPassword); provider.setCredentials(AuthScope.ANY, credentials); httpClient = HttpClients.custom().setDefaultCredentialsProvider(provider).build(); }else{ httpClient = HttpClients.createDefault(); } HttpGet httpGet = new HttpGet(uriBuilder.build()); response = httpClient.execute(httpGet); HttpEntity entity = response.getEntity(); if (entity != null) { InputStream instream = entity.getContent(); try { byte[] _r = new byte[FILE_BUF]; int length; while ((length = instream.read(_r)) != -1) { tempLocalFile.seek(localSize); tempLocalFile.write(_r, 0, length); localSize = localSize + length; } } catch (Exception e) { result = false; e.printStackTrace(); throw new Exception(); } finally { if(instream != null){ instream.close(); } } } } catch (Exception e){ e.printStackTrace(); result = false; throw new Exception(); } finally { if(response != null){ response.close(); } if(tempLocalFile != null){ tempLocalFile.close(); } } } if (localSize == fileSize) { try{ moveFile(tempLocalPath, localPath); }catch (Exception e){ result = false; e.printStackTrace(); } }else{ result = false; } params.put("currentSize", localSize); //下载完成，并且在linux系统下，更改权限 return result; } public static void moveFile(String source, String target) { try { Files.move(Paths.get(source), Paths.get(target), StandardCopyOption.REPLACE_EXISTING); System.out.println("File is moved successful!"); } catch (Exception e) { System.out.println("File is failed to move!"); e.printStackTrace(); } } public static long getFileSize(String url, String authorUserName, String authorPassword) { CloseableHttpClient httpClient; Lon