java 文件断点续下载源码及实例 支持Etag HTTP认证用户名密码
Hi，大家好，我是编程小6，很荣幸遇见你，我把这些年在开发过程中遇到的问题或想法写出来，今天说一说java 文件断点续下载源码及实例 支持Etag HTTP认证用户名密码,希望能够帮助你!!!。
以下为java下载网络文件的实例，可支持断点继续下载：
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;
Long size = -2L;
try{
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(url);
Header header;
CloseableHttpResponse closeableHttpResponse = httpClient.execute(httpget);
int statusCode = closeableHttpResponse.getStatusLine().getStatusCode();
if (statusCode > 400) {
return size;
}
header = closeableHttpResponse.getFirstHeader("Content-Length");
if (header != null) {
if (null != header.getValue()) {
size = Long.parseLong(header.getValue());
}
}
closeableHttpResponse.close();
httpClient.close();
}catch (Exception e){
e.printStackTrace();
}
return size;
}
public static String getFileEtag(String url, String authorUserName, String authorPassword) {
CloseableHttpClient httpClient;
String eTag = "";
try{
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(url);
Header header;
CloseableHttpResponse closeableHttpResponse = httpClient.execute(httpget);
int statusCode = closeableHttpResponse.getStatusLine().getStatusCode();
if (statusCode > 400) {
return eTag;
}
header = closeableHttpResponse.getFirstHeader("Etag");
if (header != null) {
if (null != header.getValue()) {
eTag = header.getValue().replace("\"","");
}
}else{
header = closeableHttpResponse.getFirstHeader("ETag");
if (null != header.getValue()) {
eTag = header.getValue().replace("\"","");
}
}
closeableHttpResponse.close();
httpClient.close();
}catch (Exception e){
e.printStackTrace();
}
return eTag;
}
public static boolean checkRange(String fileUrl, String authorUserName, String authorPassword) throws IOException {
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(fileUrl);
httpget.addHeader("Range", "bytes=0-");
CloseableHttpResponse closeableHttpResponse = httpClient.execute(httpget);
Header header = closeableHttpResponse.getFirstHeader("Content-Range");
if (header != null && header.getValue().length() > "bytes ".length()) {
closeableHttpResponse.close();
httpClient.close();
return true;
}
closeableHttpResponse.close();
httpClient.close();
return false;
}
public static String readFileContent(String path) throws IOException {
FileInputStream fis = null;
InputStreamReader isr = null;
BufferedReader br = null;
try {
fis = new FileInputStream(path);
isr = new InputStreamReader(fis, "UTF-8");
br = new BufferedReader(isr);
return br.readLine();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if(br != null){
br.close();
}
if(isr != null){
isr.close();
}
if(fis != null){
fis.close();
}
}
return null;
}
public static Boolean writeFileContent(String path, String content) {
Boolean result = true;
FileOutputStream fos = null;
OutputStreamWriter osw = null;
try {
fos = new FileOutputStream(path);
osw = new OutputStreamWriter(fos, "UTF-8");
osw.write(content);
osw.flush();
} catch (FileNotFoundException e) {
result= false;
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
result= false;
e.printStackTrace();
} catch (IOException e) {
result= false;
e.printStackTrace();
} finally {
try {
if(osw != null){
osw.close();
}
if(fos != null){
fos.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
}
public static void main(String[] args){
String fileUrl = "http://xxxxxxxx.zip";
String localPath = "D:\\file\\xxxxxx.zip";
String tempLocalPath = "D:\\file\\temp\\xxxxxx.zip";
String authorUserName = null;
String authorPassword = null;
boolean isReload = false;
try {
downloadFile(fileUrl,localPath, tempLocalPath, authorUserName, authorPassword, isReload);
} catch (Exception e) {
e.printStackTrace();
}
}
}今天的分享到此就结束了，感谢您的阅读，如果确实帮到您，您可以动动手指转发给其他人。
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