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Implement session locking in SftpController to ensure thread safety during concurrent SFTP operations. Introduce a method to handle session locks and improve error handling by forcing reconnections on exceptions. This change addresses potential issues with shared ChannelSftp instances in concurrent requests.

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liumangmang
2026-02-04 15:03:37 +08:00
parent e792fb919d
commit a61a88f36b
1 changed files with 143 additions and 47 deletions
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190
backend/src/main/java/com/sshmanager/controller/SftpController.java
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@@ -20,6 +20,7 @@ import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Supplier;
import java.util.stream.Collectors;
@RestController
@@ -33,6 +34,11 @@ public class SftpController {
private final SftpService sftpService;
private final Map<String, SftpService.SftpSession> sessions = new ConcurrentHashMap<>();
/**
* JSch ChannelSftp is not thread-safe. If the frontend triggers concurrent requests (e.g. rapid ".." navigation),
* sharing one ChannelSftp can crash with internal stream exceptions. We serialize all SFTP ops per (user, connection).
*/
private final Map<String, Object> sessionLocks = new ConcurrentHashMap<>();
public SftpController(ConnectionService connectionService,
UserRepository userRepository,
@@ -51,6 +57,13 @@ public class SftpController {
return userId + ":" + connectionId;
}
private <T> T withSessionLock(String key, Supplier<T> action) {
Object lock = sessionLocks.computeIfAbsent(key, k -> new Object());
synchronized (lock) {
return action.get();
}
}
private SftpService.SftpSession getOrCreateSession(Long connectionId, Long userId) throws Exception {
String key = sessionKey(userId, connectionId);
SftpService.SftpSession session = sessions.get(key);
@@ -72,12 +85,24 @@ public class SftpController {
Authentication authentication) {
try {
Long userId = getCurrentUserId(authentication);
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
List<SftpService.FileInfo> files = sftpService.listFiles(session, path);
List<SftpFileInfo> dtos = files.stream()
.map(f -> new SftpFileInfo(f.name, f.directory, f.size, f.mtime))
.collect(Collectors.toList());
return ResponseEntity.ok(dtos);
String key = sessionKey(userId, connectionId);
return withSessionLock(key, () -> {
try {
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
List<SftpService.FileInfo> files = sftpService.listFiles(session, path);
List<SftpFileInfo> dtos = files.stream()
.map(f -> new SftpFileInfo(f.name, f.directory, f.size, f.mtime))
.collect(Collectors.toList());
return ResponseEntity.ok(dtos);
} catch (Exception e) {
// If the underlying SFTP channel got into a bad state, force reconnect on next request.
SftpService.SftpSession existing = sessions.remove(key);
if (existing != null) {
existing.disconnect();
}
throw new RuntimeException(e);
}
});
} catch (Exception e) {
String errorMsg = toSftpErrorMessage(e, path, "list");
log.warn("SFTP list failed: connectionId={}, path={}, error={}", connectionId, path, errorMsg, e);
@@ -91,12 +116,16 @@ public class SftpController {
if (e.getMessage() != null && !e.getMessage().trim().isEmpty()) {
return e.getMessage();
}
Throwable cause = e.getCause();
if (cause instanceof SftpException) {
return SftpService.formatSftpExceptionMessage((SftpException) cause, path, operation);
}
if (e instanceof SftpException) {
return SftpService.formatSftpExceptionMessage((SftpException) e, path, operation);
// Unwrap nested RuntimeExceptions to find the underlying SftpException (if any).
Throwable cur = e;
for (int i = 0; i < 10 && cur != null; i++) {
if (cur instanceof SftpException) {
return SftpService.formatSftpExceptionMessage((SftpException) cur, path, operation);
}
if (cur.getMessage() != null && !cur.getMessage().trim().isEmpty()) {
return cur.getMessage();
}
cur = cur.getCause();
}
return operation + " failed";
}
@@ -107,11 +136,22 @@ public class SftpController {
Authentication authentication) {
try {
Long userId = getCurrentUserId(authentication);
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
String pwd = sftpService.pwd(session);
Map<String, String> result = new HashMap<>();
result.put("path", pwd);
return ResponseEntity.ok(result);
String key = sessionKey(userId, connectionId);
return withSessionLock(key, () -> {
try {
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
String pwd = sftpService.pwd(session);
Map<String, String> result = new HashMap<>();
result.put("path", pwd);
return ResponseEntity.ok(result);
} catch (Exception e) {
SftpService.SftpSession existing = sessions.remove(key);
if (existing != null) {
existing.disconnect();
}
throw new RuntimeException(e);
}
});
} catch (Exception e) {
log.warn("SFTP pwd failed: connectionId={}", connectionId, e);
Map<String, String> err = new HashMap<>();
@@ -127,13 +167,24 @@ public class SftpController {
Authentication authentication) {
try {
Long userId = getCurrentUserId(authentication);
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
byte[] data = sftpService.download(session, path);
String filename = path.contains("/") ? path.substring(path.lastIndexOf('/') + 1) : path;
return ResponseEntity.ok()
.header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + filename + "\"")
.contentType(MediaType.APPLICATION_OCTET_STREAM)
.body(data);
String key = sessionKey(userId, connectionId);
return withSessionLock(key, () -> {
try {
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
byte[] data = sftpService.download(session, path);
String filename = path.contains("/") ? path.substring(path.lastIndexOf('/') + 1) : path;
return ResponseEntity.ok()
.header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + filename + "\"")
.contentType(MediaType.APPLICATION_OCTET_STREAM)
.body(data);
} catch (Exception e) {
SftpService.SftpSession existing = sessions.remove(key);
if (existing != null) {
existing.disconnect();
}
throw new RuntimeException(e);
}
});
} catch (Exception e) {
return ResponseEntity.status(500).build();
}
@@ -147,14 +198,25 @@ public class SftpController {
Authentication authentication) {
try {
Long userId = getCurrentUserId(authentication);
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
String remotePath = (path == null || path.isEmpty() || path.equals("/"))
? "/" + file.getOriginalFilename()
: (path.endsWith("/") ? path + file.getOriginalFilename() : path + "/" + file.getOriginalFilename());
sftpService.upload(session, remotePath, file.getBytes());
Map<String, String> result = new HashMap<>();
result.put("message", "Uploaded");
return ResponseEntity.ok(result);
String key = sessionKey(userId, connectionId);
return withSessionLock(key, () -> {
try {
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
String remotePath = (path == null || path.isEmpty() || path.equals("/"))
? "/" + file.getOriginalFilename()
: (path.endsWith("/") ? path + file.getOriginalFilename() : path + "/" + file.getOriginalFilename());
sftpService.upload(session, remotePath, file.getBytes());
Map<String, String> result = new HashMap<>();
result.put("message", "Uploaded");
return ResponseEntity.ok(result);
} catch (Exception e) {
SftpService.SftpSession existing = sessions.remove(key);
if (existing != null) {
existing.disconnect();
}
throw new RuntimeException(e);
}
});
} catch (Exception e) {
Map<String, String> error = new HashMap<>();
error.put("error", e.getMessage());
@@ -170,11 +232,22 @@ public class SftpController {
Authentication authentication) {
try {
Long userId = getCurrentUserId(authentication);
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
sftpService.delete(session, path, directory);
Map<String, String> result = new HashMap<>();
result.put("message", "Deleted");
return ResponseEntity.ok(result);
String key = sessionKey(userId, connectionId);
return withSessionLock(key, () -> {
try {
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
sftpService.delete(session, path, directory);
Map<String, String> result = new HashMap<>();
result.put("message", "Deleted");
return ResponseEntity.ok(result);
} catch (Exception e) {
SftpService.SftpSession existing = sessions.remove(key);
if (existing != null) {
existing.disconnect();
}
throw new RuntimeException(e);
}
});
} catch (Exception e) {
Map<String, String> error = new HashMap<>();
error.put("error", e.getMessage());
@@ -189,11 +262,22 @@ public class SftpController {
Authentication authentication) {
try {
Long userId = getCurrentUserId(authentication);
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
sftpService.mkdir(session, path);
Map<String, String> result = new HashMap<>();
result.put("message", "Created");
return ResponseEntity.ok(result);
String key = sessionKey(userId, connectionId);
return withSessionLock(key, () -> {
try {
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
sftpService.mkdir(session, path);
Map<String, String> result = new HashMap<>();
result.put("message", "Created");
return ResponseEntity.ok(result);
} catch (Exception e) {
SftpService.SftpSession existing = sessions.remove(key);
if (existing != null) {
existing.disconnect();
}
throw new RuntimeException(e);
}
});
} catch (Exception e) {
Map<String, String> error = new HashMap<>();
error.put("error", e.getMessage());
@@ -209,11 +293,22 @@ public class SftpController {
Authentication authentication) {
try {
Long userId = getCurrentUserId(authentication);
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
sftpService.rename(session, oldPath, newPath);
Map<String, String> result = new HashMap<>();
result.put("message", "Renamed");
return ResponseEntity.ok(result);
String key = sessionKey(userId, connectionId);
return withSessionLock(key, () -> {
try {
SftpService.SftpSession session = getOrCreateSession(connectionId, userId);
sftpService.rename(session, oldPath, newPath);
Map<String, String> result = new HashMap<>();
result.put("message", "Renamed");
return ResponseEntity.ok(result);
} catch (Exception e) {
SftpService.SftpSession existing = sessions.remove(key);
if (existing != null) {
existing.disconnect();
}
throw new RuntimeException(e);
}
});
} catch (Exception e) {
Map<String, String> error = new HashMap<>();
error.put("error", e.getMessage());
@@ -267,6 +362,7 @@ public class SftpController {
if (session != null) {
session.disconnect();
}
sessionLocks.remove(key);
Map<String, String> result = new HashMap<>();
result.put("message", "Disconnected");
return ResponseEntity.ok(result);