Java 使用JSch使用多线程下载文件
我正在尝试使用多个线程从远程服务器下载多个文件。然而,当我使用多个线程时,我得到 java.lang.IOException:管道已关闭 当我只使用一个线程时,同样的代码可以正常工作 是否不可能使用JSch从同一远程服务器同时下载多个文件 SftpTest.javaJava 使用JSch使用多线程下载文件,java,jsch,Java,Jsch,我正在尝试使用多个线程从远程服务器下载多个文件。然而,当我使用多个线程时,我得到 java.lang.IOException:管道已关闭 当我只使用一个线程时,同样的代码可以正常工作 是否不可能使用JSch从同一远程服务器同时下载多个文件 SftpTest.java public class SftpTest { private static List<SftpAccessor> accessorList = new ArrayList<SftpAccessor>();
public class SftpTest {
private static List<SftpAccessor> accessorList = new ArrayList<SftpAccessor>();
private static List<Payload> files = new ArrayList<Payload>();
private static ExecutorService writerThreadPool = Executors.newFixedThreadPool(10);
public static void main(String args[]) throws JSchException, InterruptedException {
SSH srcServer = new SSH();
srcServer.setHostname("10.22.65.140");
srcServer.setKey("D:\\jars\\dmwvmcol01.ec2user.pem");
srcServer.setPort("22");
srcServer.setUsername("ec2-user");
SftpAccessor acc = new SftpAccessor(srcServer);
accessorList.add(acc);
files.addAll(acc.ls("/data/test/src", false, "*", 1));
for (Payload file : files) {
writerThreadPool.submit(new LocalWriterThread(file));
}
writerThreadPool.shutdown();
writerThreadPool.awaitTermination(20, TimeUnit.MINUTES);
}}
SftpAccessor.java
public class SftpAccessor {
private JSch jsch = new JSch();
private ChannelSftp channelSftp = null;
private Session session = null;
String errorMsg = null;
public SftpAccessor(SSH ssh) throws JSchException {
jsch.addIdentity(ssh.getKey());
session = jsch.getSession(ssh.getUsername(), ssh.getHostname(), Integer.parseInt(ssh.getPort()));
session.setHostKeyAlias(ssh.getKey());
java.util.Properties config = new java.util.Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
session.connect();
channelSftp = (ChannelSftp) session.openChannel("sftp");
channelSftp.connect();
}
public List<Payload> ls(String directory, boolean recursive, String filemask, int delayMinutes) {
List<Payload> files = new ArrayList<Payload>();
try {
channelSftp.cd(directory);
@SuppressWarnings("unchecked")
Vector<ChannelSftp.LsEntry> entries = channelSftp.ls(filemask);
for (ChannelSftp.LsEntry entry : entries) {
try {
if (entry.getAttrs().isDir()) {
if (recursive) {
List<Payload> filesToAdd = ls(directory + "/" + entry.getFilename(), recursive, filemask, delayMinutes);
files.addAll(filesToAdd);
}
}
else {
Date lastmodified = new Date(entry.getAttrs().getMTime() * 1000L);
Date currdate = new Date(new Date().getTime() - (delayMinutes * 60 * 1000L));
if (lastmodified.before(currdate)) {
String filename = entry.getFilename();
entry.getAttrs().getMTime();
Payload file = new Payload();
System.out.println("Getting input Stream for " + directory + "/" + filename);
file.setInputStream(channelSftp.get(directory + "/" + filename));
file.setFilename(filename);
file.setLastModified(lastmodified);
files.add(file);
}
}
}
catch (Exception e) {
e.printStackTrace();
}
}
}
catch (SftpException e) {
}
return files;
}}
JSch不是线程安全的。即使是这样,在单个SSH会话上使用并行下载也几乎没有任何性能优势。它会像串行下载一样慢。此外,您可能会达到并发文件句柄的服务器端限制 您应该为每个线程/下载打开单独的会话
public class SSH {
String hostname;
String port;
String username;
String key;
public String getHostname() {
return hostname;
}
public void setHostname(String hostname) {
this.hostname = hostname;
}
public String getPort() {
return port;
}
public void setPort(String port) {
this.port = port;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getKey() {
return key;
}
public void setKey(String key) {
this.key = key;
} }
public class SftpAccessor {
private JSch jsch = new JSch();
private ChannelSftp channelSftp = null;
private Session session = null;
String errorMsg = null;
public SftpAccessor(SSH ssh) throws JSchException {
jsch.addIdentity(ssh.getKey());
session = jsch.getSession(ssh.getUsername(), ssh.getHostname(), Integer.parseInt(ssh.getPort()));
session.setHostKeyAlias(ssh.getKey());
java.util.Properties config = new java.util.Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
session.connect();
channelSftp = (ChannelSftp) session.openChannel("sftp");
channelSftp.connect();
}
public List<Payload> ls(String directory, boolean recursive, String filemask, int delayMinutes) {
List<Payload> files = new ArrayList<Payload>();
try {
channelSftp.cd(directory);
@SuppressWarnings("unchecked")
Vector<ChannelSftp.LsEntry> entries = channelSftp.ls(filemask);
for (ChannelSftp.LsEntry entry : entries) {
try {
if (entry.getAttrs().isDir()) {
if (recursive) {
List<Payload> filesToAdd = ls(directory + "/" + entry.getFilename(), recursive, filemask, delayMinutes);
files.addAll(filesToAdd);
}
}
else {
Date lastmodified = new Date(entry.getAttrs().getMTime() * 1000L);
Date currdate = new Date(new Date().getTime() - (delayMinutes * 60 * 1000L));
if (lastmodified.before(currdate)) {
String filename = entry.getFilename();
entry.getAttrs().getMTime();
Payload file = new Payload();
System.out.println("Getting input Stream for " + directory + "/" + filename);
file.setInputStream(channelSftp.get(directory + "/" + filename));
file.setFilename(filename);
file.setLastModified(lastmodified);
files.add(file);
}
}
}
catch (Exception e) {
e.printStackTrace();
}
}
}
catch (SftpException e) {
}
return files;
}}
public class Payload {
private String filename;
private InputStream inputStream;
private Date lastModified;
public String getFilename() {
return filename;
}
public void setFilename(String filename) {
this.filename = filename;
}
public Date getLastModified() {
return lastModified;
}
public void setLastModified(Date lastModified) {
this.lastModified = lastModified;
}
public InputStream getInputStream() {
return inputStream;
}
public void setInputStream(InputStream inputStream) {
this.inputStream = inputStream;
}}