HMCL-dev · ToobLac · May 3, 2026 · May 3, 2026 · May 4, 2026 · May 4, 2026
diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/setting/LauncherSettings.java b/HMCL/src/main/java/org/jackhuang/hmcl/setting/LauncherSettings.java
@@ -178,6 +178,13 @@ public BooleanProperty disableAutoShowUpdateDialogProperty() {
         return disableAutoShowUpdateDialog;
     }
 
+    @SerializedName("autoDownloadUpdate")
+    private final BooleanProperty autoDownloadUpdate = new SimpleBooleanProperty(false);
+
+    public BooleanProperty autoDownloadUpdateProperty() {
+        return autoDownloadUpdate;
+    }
+
     /// Whether April Fools features are disabled.
     @SerializedName("disableAprilFools")
     private final BooleanProperty disableAprilFools = new SimpleBooleanProperty(false);

diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/ui/main/SettingsPage.java b/HMCL/src/main/java/org/jackhuang/hmcl/ui/main/SettingsPage.java
@@ -20,6 +20,7 @@
 import com.jfoenix.controls.JFXButton;
 import javafx.beans.InvalidationListener;
 import javafx.beans.WeakInvalidationListener;
+import javafx.beans.property.BooleanProperty;
 import javafx.beans.property.ObjectProperty;
 import javafx.beans.property.StringProperty;
 import javafx.css.PseudoClass;
@@ -86,7 +87,6 @@ public SettingsPage() {
             {
                 ObjectProperty<UpdateChannel> updateChannel;
                 {
-
                     JFXButton updateButton = FXUtils.newToggleButton4(SVG.UPDATE, 20);
                     updateButton.setOnAction(e -> onUpdate());
                     updateButton.setPadding(Insets.EMPTY);
@@ -139,17 +139,13 @@ protected int getTrailingTextIndex() {
                     updatePaneList.getContent().add(updatePane);
                 }
 
+                BooleanProperty preview;
                 {
                     LineToggleButton previewPane = new LineToggleButton();
                     previewPane.setTitle(i18n("update.preview"));
                     previewPane.setSubtitle(i18n("update.preview.subtitle"));
                     previewPane.selectedProperty().bindBidirectional(settings().acceptPreviewUpdateProperty());
-
-                    InvalidationListener checkUpdateListener = e -> {
-                        UpdateChecker.requestCheckUpdate(updateChannel.get(), previewPane.isSelected());
-                    };
-                    updateChannel.addListener(checkUpdateListener);
-                    previewPane.selectedProperty().addListener(checkUpdateListener);
+                    preview = previewPane.selectedProperty();
 
                     updatePaneList.getContent().add(previewPane);
                 }
@@ -162,6 +158,26 @@ protected int getTrailingTextIndex() {
                     updatePaneList.getContent().add(disableAutoShowUpdateDialogPane);
                 }
 
+                BooleanProperty autoDownloadUpdate;
+                {
+                    LineToggleButton autoDownloadUpdatePane = new LineToggleButton();
+                    autoDownloadUpdatePane.setTitle(i18n("update.auto_download"));
+                    autoDownloadUpdatePane.setSubtitle(i18n("update.auto_download.subtitle"));
+                    autoDownloadUpdatePane.selectedProperty().bindBidirectional(settings().autoDownloadUpdateProperty());
+                    autoDownloadUpdate = autoDownloadUpdatePane.selectedProperty();
+
+                    updatePaneList.getContent().add(autoDownloadUpdatePane);
+                }
+
+                {
+                    InvalidationListener checkUpdateListener = e -> {
+                        UpdateChecker.requestCheckUpdate(updateChannel.get(), preview.get(), autoDownloadUpdate.get());
+                    };
+                    updateChannel.addListener(checkUpdateListener);
+                    preview.addListener(checkUpdateListener);
+                    autoDownloadUpdate.addListener(checkUpdateListener);
+                }
+
                 rootPane.getChildren().addAll(ComponentList.createComponentListTitle(i18n("update")), updatePaneList);
             }
 

diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/upgrade/RemoteVersion.java b/HMCL/src/main/java/org/jackhuang/hmcl/upgrade/RemoteVersion.java
@@ -22,15 +22,24 @@
 import com.google.gson.JsonParseException;
 import org.jackhuang.hmcl.task.FileDownloadTask.IntegrityCheck;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
+import org.jackhuang.hmcl.util.io.FileUtils;
 import org.jackhuang.hmcl.util.io.NetworkUtils;
 import org.jetbrains.annotations.NotNull;
 
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Map;
 import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static org.jackhuang.hmcl.util.logging.Logger.LOG;
 
 public record RemoteVersion(UpdateChannel channel, String version, String url, Type type, IntegrityCheck integrityCheck,
                             boolean preview, boolean force) {
 
+    public static final Map<RemoteVersion, Path> downloadCache = new ConcurrentHashMap<>();
+
     public static RemoteVersion fetch(UpdateChannel channel, boolean preview, String url) throws IOException {
         try {
             JsonObject response = JsonUtils.fromNonNullJson(NetworkUtils.doGet(url), JsonObject.class);
@@ -53,6 +62,29 @@ public static RemoteVersion fetch(UpdateChannel channel, boolean preview, String
         return "[" + version + " from " + url + "]";
     }
 
+    public void tryDownload() {
+        Path downloaded = downloadCache.get(this);
+        if (downloaded != null && FileUtils.verifyHash(downloaded, integrityCheck().algorithm(), integrityCheck().checksum())) return;
+
+        try {
+            downloaded = Files.createTempFile("hmcl-update-", ".jar");
+        } catch (IOException e) {
+            LOG.warning("Failed to create temp file", e);
+            return;
+        }
+
+        var executor = new HMCLDownloadTask(this, downloaded).executor();
+        if (executor.test()) {
+            downloadCache.put(this, downloaded);
+        } else {
+            LOG.warning("Failed to download update for " + this, executor.getException());
+            try {
+                Files.deleteIfExists(downloaded);
+            } catch (IOException ignored) {
+            }
+        }
+    }
+
     public enum Type {
         JAR
     }

diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/upgrade/UpdateChecker.java b/HMCL/src/main/java/org/jackhuang/hmcl/upgrade/UpdateChecker.java
@@ -21,7 +21,6 @@
 import javafx.beans.binding.Bindings;
 import javafx.beans.binding.BooleanBinding;
 import javafx.beans.property.*;
-import javafx.beans.value.ObservableBooleanValue;
 import org.jackhuang.hmcl.Metadata;
 import org.jackhuang.hmcl.util.io.NetworkUtils;
 import org.jackhuang.hmcl.util.versioning.VersionNumber;
@@ -38,25 +37,14 @@ private UpdateChecker() {
     }
 
     private static final ObjectProperty<RemoteVersion> latestVersion = new SimpleObjectProperty<>();
-    private static final BooleanBinding outdated = Bindings.createBooleanBinding(
-            () -> {
-                RemoteVersion latest = latestVersion.get();
-                if (latest == null || isDevelopmentVersion(Metadata.VERSION)) {
-                    return false;
-                } else if (latest.force()
-                        || Metadata.isNightly()
-                        || latest.channel() == UpdateChannel.NIGHTLY
-                        || latest.channel() != UpdateChannel.getChannel()) {
-                    return !latest.version().equals(Metadata.VERSION);
-                } else {
-                    return VersionNumber.compare(Metadata.VERSION, latest.version()) < 0;
-                }
-            },
-            latestVersion);
-    private static final ReadOnlyBooleanWrapper checkingUpdate = new ReadOnlyBooleanWrapper(false);
+    private static final ReadOnlyBooleanWrapper outdated = new ReadOnlyBooleanWrapper(false);
+    private static final IntegerProperty runningThreads = new SimpleIntegerProperty(0);
+    private static final BooleanBinding checkingUpdate = Bindings.createBooleanBinding(() -> runningThreads.get() > 0, runningThreads);
+
+    private static UpdateTarget desiredTarget = null;
 
     public static void init() {
-        requestCheckUpdate(UpdateChannel.getChannel(), settings().acceptPreviewUpdateProperty().get());
+        requestCheckUpdate(UpdateChannel.getChannel(), settings().acceptPreviewUpdateProperty().get(), settings().autoDownloadUpdateProperty().get());
     }
 
     public static RemoteVersion getLatestVersion() {
@@ -71,16 +59,16 @@ public static boolean isOutdated() {
         return outdated.get();
     }
 
-    public static ObservableBooleanValue outdatedProperty() {
+    public static ReadOnlyBooleanProperty outdatedProperty() {
         return outdated;
     }
 
     public static boolean isCheckingUpdate() {
         return checkingUpdate.get();
     }
 
-    public static ReadOnlyBooleanProperty checkingUpdateProperty() {
-        return checkingUpdate.getReadOnlyProperty();
+    public static BooleanBinding checkingUpdateProperty() {
+        return checkingUpdate;
     }
 
     private static RemoteVersion checkUpdate(UpdateChannel channel, boolean preview) throws IOException {
@@ -101,29 +89,59 @@ private static boolean isDevelopmentVersion(String version) {
                 version.contains("SNAPSHOT"); // eg. 3.5.SNAPSHOT
     }
 
-    public static void requestCheckUpdate(UpdateChannel channel, boolean preview) {
+    private static boolean checkOutdated(RemoteVersion latest) {
+        if (latest == null || isDevelopmentVersion(Metadata.VERSION)) {
+            return false;
+        } else if (latest.force()
+                || Metadata.isNightly()
+                || latest.channel() == UpdateChannel.NIGHTLY
+                || latest.channel() != UpdateChannel.getChannel()) {
+            return !latest.version().equals(Metadata.VERSION);
+        } else {
+            return VersionNumber.compare(Metadata.VERSION, latest.version()) < 0;
+        }
+    }
+
+    public static void requestCheckUpdate(UpdateChannel channel, boolean preview, boolean download) {
+        requestCheckUpdate(new UpdateTarget(channel, preview, download));
+    }
+
+    private static void requestCheckUpdate(UpdateTarget target) {
         Platform.runLater(() -> {
-            if (isCheckingUpdate())
+            if (isCheckingUpdate() && target.concealedBy(desiredTarget))
                 return;
-            checkingUpdate.set(true);
+            runningThreads.set(runningThreads.get() + 1);
+            desiredTarget = target;
 
             thread(() -> {
                 RemoteVersion result = null;
+                boolean b = false;
                 try {
-                    result = checkUpdate(channel, preview);
-                    LOG.info("Latest version (" + channel + ", preview=" + preview + ") is " + result);
+                    result = checkUpdate(target.channel(), target.preview());
+                    b = checkOutdated(result);
+                    LOG.info("Latest version (" + target.channel() + ", preview=" + target.preview() + ") is " + result);
+                    if (target.download() && b) result.tryDownload();
                 } catch (Throwable e) {
                     LOG.warning("Failed to check for update", e);
                 }
+                boolean isOutdated = b;
 
                 RemoteVersion finalResult = result;
                 Platform.runLater(() -> {
-                    if (finalResult != null) {
+                    if (finalResult != null && target.concealedBy(desiredTarget)) {
-                    if (finalResult != null && target.concealedBy(desiredTarget)) {
+                    if (finalResult != null && target.isSameSource(desiredTarget)) {
-                    if (finalResult != null && target.concealedBy(desiredTarget)) {
+                    if (finalResult != null && target.isSameSource(desiredTarget)) {
                         latestVersion.set(finalResult);
+                        outdated.set(isOutdated);
                     }
-                    checkingUpdate.set(false);
+                    runningThreads.set(runningThreads.get() - 1);
                 });
             }, "Update Checker", true);
         });
     }
+
+    private record UpdateTarget(UpdateChannel channel, boolean preview, boolean download) {
+        public boolean concealedBy(UpdateTarget other) {
+            if (other == null) return false;
+            return other.channel == channel && other.preview == preview && (!download || other.download);
+        }
+    }
 }
diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/upgrade/UpdateHandler.java b/HMCL/src/main/java/org/jackhuang/hmcl/upgrade/UpdateHandler.java
@@ -33,6 +33,7 @@
 import org.jackhuang.hmcl.util.StringUtils;
 import org.jackhuang.hmcl.util.SwingUtils;
 import org.jackhuang.hmcl.util.TaskCancellationAction;
+import org.jackhuang.hmcl.util.io.FileUtils;
 import org.jackhuang.hmcl.util.io.JarUtils;
 import org.jackhuang.hmcl.util.platform.OperatingSystem;
 
@@ -106,22 +107,26 @@ public static void updateFrom(RemoteVersion version) {
         }
 
         Controllers.dialog(new UpgradeDialog(version, () -> {
-            Path downloaded;
-            try {
-                downloaded = Files.createTempFile("hmcl-update-", ".jar");
-            } catch (IOException e) {
-                LOG.warning("Failed to create temp file", e);
-                return;
-            }
-
-            Task<?> task = new HMCLDownloadTask(version, downloaded);
+            Path downloaded = RemoteVersion.downloadCache.get(version);
+            TaskExecutor executor;
+            if (downloaded != null && FileUtils.verifyHash(downloaded, version.integrityCheck().algorithm(), version.integrityCheck().checksum())) {
+                executor = Task.completed(null).executor();
+            } else {
+                try {
+                    downloaded = Files.createTempFile("hmcl-update-", ".jar");
+                } catch (IOException e) {
+                    LOG.warning("Failed to create temp file", e);
+                    return;
+                }
 
-            TaskExecutor executor = task.executor();
-            Controllers.taskDialog(executor, i18n("message.downloading"), TaskCancellationAction.NORMAL);
+                Task<?> task = new HMCLDownloadTask(version, downloaded);
+                executor = task.executor();
+                Controllers.taskDialog(executor, i18n("message.downloading"), TaskCancellationAction.NORMAL);
+            }
+            final Path finalDownloaded = downloaded;
             thread(() -> {
-                boolean success = executor.test();
-
-                if (success) {
+                if (executor.test()) {
+                    RemoteVersion.downloadCache.put(version, finalDownloaded);
                     try {
                         if (!IntegrityChecker.isSelfVerified() && !IntegrityChecker.DISABLE_SELF_INTEGRITY_CHECK) {
                             throw new IOException("Current JAR is not verified");
@@ -150,7 +155,7 @@ public static void updateFrom(RemoteVersion version) {
                             // Ignore
                         }
 
-                        requestUpdate(downloaded, getCurrentLocation());
+                        requestUpdate(finalDownloaded, getCurrentLocation());
                         EntryPoint.exit(0);
                     } catch (IOException e) {
                         LOG.warning("Failed to update to " + version, e);

diff --git a/HMCL/src/main/resources/assets/lang/I18N.properties b/HMCL/src/main/resources/assets/lang/I18N.properties
@@ -1699,6 +1699,8 @@ unofficial.hint=You are using an unofficial build of HMCL. We cannot guarantee i
 
 update=Update
 update.accept=Update
+update.auto_download=Auto download update
+update.auto_download.subtitle=Automatically download launcher updates and notify when ready to install.
 update.changelog=Changelog
 update.channel.dev=Beta
 update.channel.dev.hint=You are currently using a Beta channel build of the launcher. While it may include some extra features, it is also sometimes less stable than the Stable channel builds.\n\

diff --git a/HMCL/src/main/resources/assets/lang/I18N_zh.properties b/HMCL/src/main/resources/assets/lang/I18N_zh.properties
@@ -1490,6 +1490,8 @@ unofficial.hint=你正在使用非官方構建的 HMCL。我們無法保證其
 
 update=啟動器更新
 update.accept=更新
+update.auto_download=自動下載更新
+update.auto_download.subtitle=自動在背景下載更新，下載完成後顯示通知
 update.changelog=更新日誌
 update.channel.dev=開發版
 update.channel.dev.hint=你正在使用 HMCL 開發版。開發版包含一些未在穩定版中包含的測試性功能，僅用於體驗新功能。開發版功能未受充分驗證，使用起來可能不穩定！\n\

diff --git a/HMCL/src/main/resources/assets/lang/I18N_zh_CN.properties b/HMCL/src/main/resources/assets/lang/I18N_zh_CN.properties
@@ -1495,6 +1495,8 @@ unofficial.hint=你正在使用非官方构建的 HMCL。我们无法保证其
 
 update=启动器更新
 update.accept=更新
+update.auto_download=自动下载更新
+update.auto_download.subtitle=自动在后台下载更新，下载完成后显示通知
 update.changelog=更新日志
 update.channel.dev=开发版
 update.channel.dev.hint=你正在使用 HMCL 开发版。开发版包含一些未在稳定版中包含的测试性功能，仅用于体验新功能。开发版功能未受充分验证，使用起来可能不稳定！<a href="https://hmcl.huangyuhui.net/download">下载稳定版</a>\n\

diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/util/CacheRepository.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/util/CacheRepository.java
@@ -103,15 +103,7 @@ protected Path getFile(String algorithm, String hash) {
     protected boolean fileExists(String algorithm, String hash) {
         if (!DigestUtils.isSha1Digest(hash)) return false;
         Path file = getFile(algorithm, hash);
-        if (Files.exists(file)) {
-            try {
-                return DigestUtils.digestToString(algorithm, file).equalsIgnoreCase(hash);
-            } catch (IOException e) {
-                return false;
-            }
-        } else {
-            return false;
-        }
+        return FileUtils.verifyHash(file, algorithm, hash);
     }
 
     private void checkHash(String hash) throws IOException {

diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/util/io/FileUtils.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/util/io/FileUtils.java
@@ -20,6 +20,7 @@
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import org.glavo.chardet.DetectedCharset;
 import org.glavo.chardet.UniversalDetector;
+import org.jackhuang.hmcl.util.DigestUtils;
 import org.jackhuang.hmcl.util.StringUtils;
 import org.jackhuang.hmcl.util.function.ExceptionalConsumer;
 import org.jackhuang.hmcl.util.platform.OperatingSystem;
@@ -573,4 +574,17 @@ public static EnumSet<PosixFilePermission> parsePosixFilePermission(int unixMode
 
         return permissions;
     }
+
+    public static boolean verifyHash(Path file, String algorithm, String hash) {
+        if (Files.isRegularFile(file)) {
+            try {
+                return DigestUtils.digestToString(algorithm, file).equalsIgnoreCase(hash);
+            } catch (IOException e) {
+                LOG.warning("Failed to verify hash for file " + file, e);
+                return false;
+            }
+        } else {
+            return false;
+        }
+    }
 }