重构 MyBatis 生成输出布局与结果反馈

src/main/java/com/example/workutils/biz/mybatisgenerator/MyBatisGeneratorWindow.java

@@ -2,6 +2,11 @@ package com.example.workutils.biz.mybatisgenerator;
 
 import com.example.workutils.biz.mybatisgenerator.application.GenerateArtifactsRequest;
 import com.example.workutils.biz.mybatisgenerator.application.GenerateArtifactsUseCase;
+import com.example.workutils.biz.mybatisgenerator.application.GenerationPlan;
+import com.example.workutils.biz.mybatisgenerator.application.GenerationPlanner;
+import com.example.workutils.biz.mybatisgenerator.application.GenerationResult;
+import com.example.workutils.biz.mybatisgenerator.application.OutputLayout;
+import com.example.workutils.biz.mybatisgenerator.application.OutputLayoutPolicy;
 import com.example.workutils.biz.mybatisgenerator.application.QueryTablesRequest;
 import com.example.workutils.biz.mybatisgenerator.application.QueryTablesUseCase;
 import com.example.workutils.biz.mybatisgenerator.presentation.DatasourceSummary;
@@ -34,7 +39,6 @@ import javafx.stage.Stage;
 
 import java.io.File;
 import java.io.IOException;
-import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -57,8 +61,10 @@ public class MyBatisGeneratorWindow {
     private final WorkUtilsProperties properties;
     private final QueryTablesUseCase queryTablesUseCase;
     private final GenerateArtifactsUseCase generateArtifactsUseCase;
+    private final OutputLayoutPolicy outputLayoutPolicy;
+    private final GenerationPlanner generationPlanner;
     private final AsyncOperationController<List<String>> queryOperation;
-    private final AsyncOperationController<String> generateOperation;
+    private final AsyncOperationController<GenerationResult> generateOperation;
 
     // ---- UI 组件 ----
     private TextField patternField;
@@ -67,6 +73,8 @@ public class MyBatisGeneratorWindow {
     private TextField modelDirField;
     private TextField xmlDirField;
     private TextField mapperDirField;
+    private TextField projectRootField;
+    private CheckBox customOutputCb;
     private TreeView<String> projectTree;
     private ComboBox<String> datasourceCmb;
     private Label dbUrlLabel;
@@ -115,9 +123,11 @@ public class MyBatisGeneratorWindow {
         this.generateArtifactsUseCase = new GenerateArtifactsUseCase(
                 request -> callback.generate(
                         request.tables(),
-                        request.modelDirectory(),
+                        request.outputLayout().modelDirectory().toString(),
-                        request.xmlDirectory(),
+                        request.outputLayout().xmlDirectory().toString(),
-                        request.mapperDirectory()));
+                        request.outputLayout().mapperDirectory().toString()));
+        this.outputLayoutPolicy = new OutputLayoutPolicy();
+        this.generationPlanner = new GenerationPlanner();
         this.queryOperation = new AsyncOperationController<>(
                 AppExecutors.io(), Platform::runLater);
         this.generateOperation = new AsyncOperationController<>(
@@ -429,7 +439,32 @@ public class MyBatisGeneratorWindow {
         Label dirLabel = new Label("输出目录设置:");
         dirLabel.setFont(Theme.heading(fsSection()));
         dirLabel.setTextFill(Theme.TEXT_PRIMARY);
-        box.getChildren().add(dirLabel);
+        projectRootField = new TextField();
+        projectRootField.getStyleClass().add(Theme.CSS_TEXT_FIELD);
+        HBox.setHgrow(projectRootField, Priority.ALWAYS);
+        projectRootField.setOnAction(e -> refreshDerivedDirectories());
+        projectRootField.focusedProperty().addListener((obs, oldValue, focused) -> {
+            if (!focused) refreshDerivedDirectories();
+        });
+
+        Button browseRootBtn = StyledButton.small(
+                "浏览...", Font.font("Microsoft YaHei", fsBody() - 1));
+        browseRootBtn.setOnAction(e -> onBrowseProjectRoot());
+        Button useTreeBtn = StyledButton.small(
+                "使用选中项目", Font.font("Microsoft YaHei", fsBody() - 1));
+        useTreeBtn.setOnAction(e -> useSelectedProjectRoot());
+        Label rootLabel = new Label("项目根目录:");
+        rootLabel.setPrefWidth(110);
+        HBox rootRow = new HBox(
+                Theme.S2, rootLabel, projectRootField, browseRootBtn, useTreeBtn);
+        rootRow.setAlignment(Pos.CENTER_LEFT);
+
+        customOutputCb = new CheckBox("自定义输出目录（高级）");
+        customOutputCb.setSelected(false);
+        customOutputCb.selectedProperty().addListener((obs, oldValue, custom) -> {
+            setDirectoryFieldsEditable(custom);
+            if (!custom) refreshDerivedDirectories();
+        });
 
         HBox modelRow = createDirRow("Model (PO)", fm -> modelDirField = fm);
         modelDirField = (TextField) modelRow.getChildren().get(1);
@@ -438,9 +473,12 @@ public class MyBatisGeneratorWindow {
         HBox mapperRow = createDirRow("Mapper 接口", fm -> mapperDirField = fm);
         mapperDirField = (TextField) mapperRow.getChildren().get(1);
 
-        loadDefaultDirs();
+        initializeProjectRoot();
+        setDirectoryFieldsEditable(false);
 
-        box.getChildren().addAll(modelRow, xmlRow, mapperRow);
+        box.getChildren().addAll(
+                dirLabel, rootRow, customOutputCb,
+                modelRow, xmlRow, mapperRow);
         return box;
     }
 
@@ -458,6 +496,7 @@ public class MyBatisGeneratorWindow {
 
         Button browseBtn = StyledButton.small("浏览...", Font.font("Microsoft YaHei", fsBody() - 1));
         browseBtn.setOnAction(e -> onBrowseDir(field));
+        browseBtn.disableProperty().bind(field.editableProperty().not());
 
         Button fillBtn = StyledButton.small("填充", Font.font("Microsoft YaHei", fsBody() - 1));
         fillBtn.setOnAction(e -> {
@@ -469,44 +508,85 @@ public class MyBatisGeneratorWindow {
                 }
             }
         });
+        fillBtn.disableProperty().bind(field.editableProperty().not());
 
         if (fieldRef != null) fieldRef.accept(field);
         row.getChildren().addAll(lbl, field, browseBtn, fillBtn);
         return row;
     }
 
-    private void loadDefaultDirs() {
+    private void initializeProjectRoot() {
-        Properties p = new Properties();
+        Path root = Paths.get("").toAbsolutePath().normalize();
-        // 1. classpath 内置默认值
+        try {
-        try (InputStream is = getClass().getClassLoader().getResourceAsStream("mybatis-generator.properties")) {
+            List<String> paths = fileOperationHelper.getProjectPaths();
-            if (is != null) p.load(is);
+            if (!paths.isEmpty() && Files.isDirectory(Paths.get(paths.get(0)))) {
-        } catch (Exception ignored) {}
+                root = Paths.get(paths.get(0)).toAbsolutePath().normalize();
-        // 2. data/ 外部配置覆盖
+            }
-        Path dataFile = properties.getMybatisGeneratorFilePath();
+        } catch (Exception ignored) {
-        if (java.nio.file.Files.exists(dataFile)) {
+        }
-            try (InputStream is = new java.io.FileInputStream(dataFile.toFile())) {
+        projectRootField.setText(root.toString().replace('\\', '/'));
-                Properties externalProps = new Properties();
+        refreshDerivedDirectories();
-                externalProps.load(is);
-                p.putAll(externalProps);
-            } catch (Exception ignored) {}
     }
 
-        setDirField(modelDirField, p.getProperty("model_target_project", "./generator"));
+    private void setDirectoryFieldsEditable(boolean editable) {
-        setDirField(xmlDirField, p.getProperty("sqlmapper_target_project", "./generator"));
+        modelDirField.setEditable(editable);
-        setDirField(mapperDirField, p.getProperty("dao_target_project", "./generator"));
+        xmlDirField.setEditable(editable);
+        mapperDirField.setEditable(editable);
     }
 
-    private void setDirField(TextField field, String dir) {
+    private void refreshDerivedDirectories() {
-        if (field == null || dir == null) return;
+        if (customOutputCb != null && customOutputCb.isSelected()) return;
-        if (dir.startsWith("./") || dir.startsWith(".\\")) {
+        try {
-            field.setText(new File(dir).getAbsolutePath().replace('\\', '/'));
+            OutputLayout layout = outputLayoutPolicy.derive(
-        } else {
+                    Paths.get(projectRootField.getText().trim()));
-            field.setText(dir.replace('\\', '/'));
+            setDirectoryFields(layout);
+        } catch (IllegalArgumentException error) {
+            modelDirField.clear();
+            xmlDirField.clear();
+            mapperDirField.clear();
         }
     }
 
+    private void setDirectoryFields(OutputLayout layout) {
+        modelDirField.setText(pathText(layout.modelDirectory()));
+        xmlDirField.setText(pathText(layout.xmlDirectory()));
+        mapperDirField.setText(pathText(layout.mapperDirectory()));
+    }
+
+    private String pathText(Path path) {
+        return path.toString().replace('\\', '/');
+    }
+
     // ==================== 事件 ====================
 
+    private void onBrowseProjectRoot() {
+        DirectoryChooser chooser = new DirectoryChooser();
+        chooser.setTitle("选择项目根目录");
+        Path current = parseProjectRoot();
+        if (current != null && Files.isDirectory(current)) {
+            chooser.setInitialDirectory(current.toFile());
+        }
+        File selected = chooser.showDialog(stage);
+        if (selected != null) {
+            projectRootField.setText(pathText(selected.toPath()));
+            refreshDerivedDirectories();
+        }
+    }
+
+    private void useSelectedProjectRoot() {
+        TreeItem<String> selected = projectTree.getSelectionModel().getSelectedItem();
+        String path = buildTreePath(selected);
+        if (path != null && Files.isDirectory(Paths.get(path))) {
+            projectRootField.setText(pathText(Paths.get(path)));
+            refreshDerivedDirectories();
+        }
+    }
+
+    private Path parseProjectRoot() {
+        String text = projectRootField == null ? "" : projectRootField.getText().trim();
+        return text.isEmpty() ? null : Paths.get(text).toAbsolutePath().normalize();
+    }
+
     private void onBrowseDir(TextField targetField) {
         DirectoryChooser chooser = new DirectoryChooser();
         chooser.setTitle("选择目录");
@@ -565,28 +645,97 @@ public class MyBatisGeneratorWindow {
 
     private void onGenerate() {
         try {
-            GenerateArtifactsRequest request = new GenerateArtifactsRequest(
+            List<String> selectedTables = tableItems.stream()
-                    tableItems.stream()
                     .filter(TableItem::isSelected)
                     .map(TableItem::getTableName)
-                            .collect(Collectors.toList()),
+                    .collect(Collectors.toList());
-                    getDirText(modelDirField),
+            OutputLayout layout = buildOutputLayout();
-                    getDirText(xmlDirField),
+            GenerateArtifactsRequest request = new GenerateArtifactsRequest(
-                    getDirText(mapperDirField));
+                    selectedTables, layout);
+            GenerationPlan plan = generationPlanner.plan(selectedTables, layout);
+            if (!confirmGeneration(plan)) return;
             generateOperation.start(
                     "正在生成代码",
                     context -> generateArtifactsUseCase.execute(request),
-                    result -> showInfo("生成结果", result),
+                    result -> showInfo("生成结果", formatGenerationResult(result)),
                     error -> showAlert("生成失败: " + error.getMessage()));
-        } catch (IllegalArgumentException error) {
+        } catch (RuntimeException error) {
             showAlert(error.getMessage());
         }
     }
 
+    private OutputLayout buildOutputLayout() {
+        Path root = parseProjectRoot();
+        if (root == null) {
+            throw new IllegalArgumentException("请选择项目根目录");
+        }
+        if (!customOutputCb.isSelected()) {
+            return outputLayoutPolicy.derive(root);
+        }
+        return outputLayoutPolicy.custom(
+                root,
+                Paths.get(getDirText(modelDirField)),
+                Paths.get(getDirText(xmlDirField)),
+                Paths.get(getDirText(mapperDirField)));
+    }
+
+    private boolean confirmGeneration(GenerationPlan plan) {
+        Alert alert = new Alert(Alert.AlertType.CONFIRMATION);
+        alert.setTitle("确认生成");
+        alert.setHeaderText("即将为 " + plan.tables().size() + " 个表生成代码");
+        alert.setContentText(buildGenerationSummary(plan));
+        alert.initOwner(stage);
+        return alert.showAndWait().filter(ButtonType.OK::equals).isPresent();
+    }
+
+    private String buildGenerationSummary(GenerationPlan plan) {
+        return "表: " + String.join(", ", plan.tables())
+                + "\n\nModel: " + formatRisk(plan.modelRisk())
+                + "\nXML Mapper: " + formatRisk(plan.xmlRisk())
+                + "\nMapper 接口: " + formatRisk(plan.mapperRisk())
+                + "\n\n已有文件可能被生成器覆盖，请确认后继续。";
+    }
+
+    private String formatRisk(
+            com.example.workutils.biz.mybatisgenerator.application.DirectoryRisk risk) {
+        String state = risk.willCreate()
+                ? "待创建"
+                : "已有 " + risk.existingFileCount() + " 个相关文件";
+        return pathText(risk.directory()) + "（" + state + "）";
+    }
+
+    private String formatGenerationResult(GenerationResult result) {
+        StringBuilder text = new StringBuilder();
+        text.append("新增文件: ").append(result.createdFiles().size()).append('\n');
+        appendFiles(text, result.createdFiles());
+        text.append("\n更新文件: ").append(result.updatedFiles().size()).append('\n');
+        appendFiles(text, result.updatedFiles());
+        text.append("\n未变化文件: ").append(result.unchangedFiles().size()).append('\n');
+        if (!result.warnings().isEmpty()) {
+            text.append("\n警告:\n");
+            result.warnings().forEach(warning -> text.append("- ").append(warning).append('\n'));
+        }
+        if (!result.generatorMessage().isBlank()) {
+            text.append("\n生成器消息:\n").append(result.generatorMessage());
+        }
+        return text.toString();
+    }
+
+    private void appendFiles(StringBuilder text, List<Path> files) {
+        int visibleCount = Math.min(files.size(), 20);
+        for (int index = 0; index < visibleCount; index++) {
+            text.append("- ").append(pathText(files.get(index))).append('\n');
+        }
+        if (files.size() > visibleCount) {
+            text.append("... 另有 ").append(files.size() - visibleCount).append(" 个文件\n");
+        }
+    }
+
     private void resetForm() {
         patternField.clear();
         tableItems.clear();
-        loadDefaultDirs();
+        customOutputCb.setSelected(false);
+        initializeProjectRoot();
     }
 
     private String getDirText(TextField field) {

src/main/java/com/example/workutils/biz/mybatisgenerator/application/DirectoryRisk.java

@@ -0,0 +1,21 @@
+package com.example.workutils.biz.mybatisgenerator.application;
+
+import java.nio.file.Path;
+import java.util.Objects;
+
+public record DirectoryRisk(
+        Path directory,
+        boolean exists,
+        boolean writable,
+        boolean willCreate,
+        long existingFileCount) {
+
+    public DirectoryRisk {
+        directory = Objects.requireNonNull(directory, "directory")
+                .toAbsolutePath()
+                .normalize();
+        if (existingFileCount < 0) {
+            throw new IllegalArgumentException("existingFileCount 不能为负数");
+        }
+    }
+}

src/main/java/com/example/workutils/biz/mybatisgenerator/application/GenerateArtifactsRequest.java

@@ -5,23 +5,13 @@ import java.util.Objects;
 
 public record GenerateArtifactsRequest(
         List<String> tables,
-        String modelDirectory,
+        OutputLayout outputLayout) {
-        String xmlDirectory,
-        String mapperDirectory) {
 
     public GenerateArtifactsRequest {
         tables = List.copyOf(Objects.requireNonNull(tables, "tables"));
         if (tables.isEmpty()) {
             throw new IllegalArgumentException("请至少选择一个表");
         }
-        modelDirectory = directoryOrDefault(modelDirectory);
+        outputLayout = Objects.requireNonNull(outputLayout, "outputLayout");
-        xmlDirectory = directoryOrDefault(xmlDirectory);
-        mapperDirectory = directoryOrDefault(mapperDirectory);
-    }
-
-    private static String directoryOrDefault(String value) {
-        return value == null || value.isBlank()
-                ? "./generator"
-                : value.trim();
     }
 }

src/main/java/com/example/workutils/biz/mybatisgenerator/application/GenerateArtifactsUseCase.java

@@ -10,12 +10,26 @@ public final class GenerateArtifactsUseCase {
     }
 
     private final Gateway gateway;
+    private final GenerationPlanner planner;
 
     public GenerateArtifactsUseCase(Gateway gateway) {
-        this.gateway = Objects.requireNonNull(gateway, "gateway");
+        this(gateway, new GenerationPlanner());
     }
 
-    public String execute(GenerateArtifactsRequest request) throws Exception {
+    GenerateArtifactsUseCase(
-        return gateway.generate(Objects.requireNonNull(request, "request"));
+            Gateway gateway,
+            GenerationPlanner planner) {
+        this.gateway = Objects.requireNonNull(gateway, "gateway");
+        this.planner = Objects.requireNonNull(planner, "planner");
+    }
+
+    public GenerationResult execute(GenerateArtifactsRequest request) throws Exception {
+        GenerateArtifactsRequest safeRequest =
+                Objects.requireNonNull(request, "request");
+        planner.plan(safeRequest.tables(), safeRequest.outputLayout());
+        OutputSnapshot before = OutputSnapshot.capture(safeRequest.outputLayout());
+        String message = gateway.generate(safeRequest);
+        OutputSnapshot after = OutputSnapshot.capture(safeRequest.outputLayout());
+        return before.compare(after, message);
     }
 }

src/main/java/com/example/workutils/biz/mybatisgenerator/application/GenerationPlan.java

@@ -0,0 +1,30 @@
+package com.example.workutils.biz.mybatisgenerator.application;
+
+import java.util.List;
+import java.util.Objects;
+
+public record GenerationPlan(
+        List<String> tables,
+        DirectoryRisk modelRisk,
+        DirectoryRisk xmlRisk,
+        DirectoryRisk mapperRisk) {
+
+    public GenerationPlan {
+        tables = List.copyOf(Objects.requireNonNull(tables, "tables"));
+        modelRisk = Objects.requireNonNull(modelRisk, "modelRisk");
+        xmlRisk = Objects.requireNonNull(xmlRisk, "xmlRisk");
+        mapperRisk = Objects.requireNonNull(mapperRisk, "mapperRisk");
+    }
+
+    public void validateWritableDirectories() {
+        validate(modelRisk);
+        validate(xmlRisk);
+        validate(mapperRisk);
+    }
+
+    private void validate(DirectoryRisk risk) {
+        if (risk.exists() && !risk.writable()) {
+            throw new IllegalArgumentException("输出目录不可写: " + risk.directory());
+        }
+    }
+}

src/main/java/com/example/workutils/biz/mybatisgenerator/application/GenerationPlanner.java

@@ -0,0 +1,47 @@
+package com.example.workutils.biz.mybatisgenerator.application;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Locale;
+import java.util.Objects;
+import java.util.stream.Stream;
+
+public final class GenerationPlanner {
+
+    public GenerationPlan plan(List<String> tables, OutputLayout layout) {
+        Objects.requireNonNull(layout, "layout");
+        GenerationPlan plan = new GenerationPlan(
+                List.copyOf(Objects.requireNonNull(tables, "tables")),
+                inspect(layout.modelDirectory(), ".java"),
+                inspect(layout.xmlDirectory(), ".xml"),
+                inspect(layout.mapperDirectory(), ".java"));
+        plan.validateWritableDirectories();
+        return plan;
+    }
+
+    private DirectoryRisk inspect(Path directory, String extension) {
+        boolean exists = Files.isDirectory(directory);
+        return new DirectoryRisk(
+                directory,
+                exists,
+                !exists || Files.isWritable(directory),
+                !exists,
+                exists ? countFiles(directory, extension) : 0);
+    }
+
+    private long countFiles(Path directory, String extension) {
+        try (Stream<Path> paths = Files.walk(directory)) {
+            String suffix = extension.toLowerCase(Locale.ROOT);
+            return paths.filter(Files::isRegularFile)
+                    .filter(path -> path.getFileName().toString()
+                            .toLowerCase(Locale.ROOT).endsWith(suffix))
+                    .count();
+        } catch (IOException error) {
+            throw new UncheckedIOException(
+                    "无法检查输出目录: " + directory, error);
+        }
+    }
+}

src/main/java/com/example/workutils/biz/mybatisgenerator/application/GenerationResult.java

@@ -0,0 +1,21 @@
+package com.example.workutils.biz.mybatisgenerator.application;
+
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Objects;
+
+public record GenerationResult(
+        List<Path> createdFiles,
+        List<Path> updatedFiles,
+        List<Path> unchangedFiles,
+        List<String> warnings,
+        String generatorMessage) {
+
+    public GenerationResult {
+        createdFiles = List.copyOf(Objects.requireNonNull(createdFiles, "createdFiles"));
+        updatedFiles = List.copyOf(Objects.requireNonNull(updatedFiles, "updatedFiles"));
+        unchangedFiles = List.copyOf(Objects.requireNonNull(unchangedFiles, "unchangedFiles"));
+        warnings = List.copyOf(Objects.requireNonNull(warnings, "warnings"));
+        generatorMessage = generatorMessage == null ? "" : generatorMessage;
+    }
+}

src/main/java/com/example/workutils/biz/mybatisgenerator/application/OutputLayout.java

@@ -0,0 +1,24 @@
+package com.example.workutils.biz.mybatisgenerator.application;
+
+import java.nio.file.Path;
+import java.util.Objects;
+
+public record OutputLayout(
+        Path projectRoot,
+        Path modelDirectory,
+        Path xmlDirectory,
+        Path mapperDirectory) {
+
+    public OutputLayout {
+        projectRoot = normalize(projectRoot, "projectRoot");
+        modelDirectory = normalize(modelDirectory, "modelDirectory");
+        xmlDirectory = normalize(xmlDirectory, "xmlDirectory");
+        mapperDirectory = normalize(mapperDirectory, "mapperDirectory");
+    }
+
+    private static Path normalize(Path path, String name) {
+        return Objects.requireNonNull(path, name)
+                .toAbsolutePath()
+                .normalize();
+    }
+}

src/main/java/com/example/workutils/biz/mybatisgenerator/application/OutputLayoutPolicy.java

@@ -0,0 +1,39 @@
+package com.example.workutils.biz.mybatisgenerator.application;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Objects;
+
+public final class OutputLayoutPolicy {
+
+    public OutputLayout derive(Path projectRoot) {
+        Path root = requireProjectRoot(projectRoot);
+        return new OutputLayout(
+                root,
+                root.resolve("src/main/java"),
+                root.resolve("src/main/resources"),
+                root.resolve("src/main/java"));
+    }
+
+    public OutputLayout custom(
+            Path projectRoot,
+            Path modelDirectory,
+            Path xmlDirectory,
+            Path mapperDirectory) {
+        return new OutputLayout(
+                requireProjectRoot(projectRoot),
+                Objects.requireNonNull(modelDirectory, "modelDirectory"),
+                Objects.requireNonNull(xmlDirectory, "xmlDirectory"),
+                Objects.requireNonNull(mapperDirectory, "mapperDirectory"));
+    }
+
+    private Path requireProjectRoot(Path projectRoot) {
+        Path root = Objects.requireNonNull(projectRoot, "projectRoot")
+                .toAbsolutePath()
+                .normalize();
+        if (!Files.isDirectory(root)) {
+            throw new IllegalArgumentException("项目根目录不存在或不是目录: " + root);
+        }
+        return root;
+    }
+}

src/main/java/com/example/workutils/biz/mybatisgenerator/application/OutputSnapshot.java

@@ -0,0 +1,103 @@
+package com.example.workutils.biz.mybatisgenerator.application;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Stream;
+
+public final class OutputSnapshot {
+
+    private final Map<Path, FileFingerprint> files;
+    private final List<String> warnings;
+
+    private OutputSnapshot(
+            Map<Path, FileFingerprint> files,
+            List<String> warnings) {
+        this.files = Map.copyOf(files);
+        this.warnings = List.copyOf(warnings);
+    }
+
+    public static OutputSnapshot capture(OutputLayout layout) {
+        Map<Path, FileFingerprint> files = new LinkedHashMap<>();
+        List<String> warnings = new ArrayList<>();
+        Set<Path> roots = new LinkedHashSet<>(List.of(
+                layout.modelDirectory(),
+                layout.xmlDirectory(),
+                layout.mapperDirectory()));
+        for (Path root : roots) {
+            captureRoot(root, files, warnings);
+        }
+        return new OutputSnapshot(files, warnings);
+    }
+
+    public GenerationResult compare(
+            OutputSnapshot after,
+            String generatorMessage) {
+        List<Path> created = new ArrayList<>();
+        List<Path> updated = new ArrayList<>();
+        List<Path> unchanged = new ArrayList<>();
+        for (Map.Entry<Path, FileFingerprint> entry : after.files.entrySet()) {
+            FileFingerprint previous = files.get(entry.getKey());
+            if (previous == null) {
+                created.add(entry.getKey());
+            } else if (!previous.equals(entry.getValue())) {
+                updated.add(entry.getKey());
+            } else {
+                unchanged.add(entry.getKey());
+            }
+        }
+        created.sort(Path::compareTo);
+        updated.sort(Path::compareTo);
+        unchanged.sort(Path::compareTo);
+        List<String> combinedWarnings = new ArrayList<>(warnings);
+        combinedWarnings.addAll(after.warnings);
+        return new GenerationResult(
+                created, updated, unchanged,
+                combinedWarnings, generatorMessage);
+    }
+
+    private static void captureRoot(
+            Path root,
+            Map<Path, FileFingerprint> files,
+            List<String> warnings) {
+        if (!Files.isDirectory(root)) {
+            return;
+        }
+        try (Stream<Path> paths = Files.walk(root)) {
+            paths.filter(Files::isRegularFile)
+                    .filter(OutputSnapshot::isGeneratedSource)
+                    .forEach(path -> captureFile(path, files, warnings));
+        } catch (IOException error) {
+            warnings.add("无法扫描输出目录 " + root + ": " + error.getMessage());
+        }
+    }
+
+    private static void captureFile(
+            Path path,
+            Map<Path, FileFingerprint> files,
+            List<String> warnings) {
+        Path normalized = path.toAbsolutePath().normalize();
+        try {
+            files.put(normalized, new FileFingerprint(
+                    Files.size(normalized),
+                    Files.getLastModifiedTime(normalized).toMillis()));
+        } catch (IOException error) {
+            warnings.add("无法读取输出文件 " + normalized + ": " + error.getMessage());
+        }
+    }
+
+    private static boolean isGeneratedSource(Path path) {
+        String name = path.getFileName().toString().toLowerCase(Locale.ROOT);
+        return name.endsWith(".java") || name.endsWith(".xml");
+    }
+
+    private record FileFingerprint(long size, long modifiedMillis) {
+    }
+}

src/test/java/com/example/workutils/biz/mybatisgenerator/MyBatisGeneratorWindowArchitectureTest.java

@@ -0,0 +1,27 @@
+package com.example.workutils.biz.mybatisgenerator;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class MyBatisGeneratorWindowArchitectureTest {
+
+    @Test
+    void usesProjectRootPolicyAndAdvancedCustomDirectoryMode() throws IOException {
+        String source = Files.readString(Path.of(
+                "src/main/java/com/example/workutils/biz/mybatisgenerator/MyBatisGeneratorWindow.java"));
+
+        assertTrue(source.contains("projectRootField"));
+        assertTrue(source.contains("customOutputCb"));
+        assertTrue(source.contains("OutputLayoutPolicy"));
+        assertTrue(source.contains("setDirectoryFieldsEditable"));
+        assertTrue(source.contains("buildGenerationSummary"));
+        assertTrue(source.contains("formatGenerationResult"));
+        assertFalse(source.contains("Files.walk"));
+    }
+}

src/test/java/com/example/workutils/biz/mybatisgenerator/application/GenerationPlannerTest.java

@@ -0,0 +1,52 @@
+package com.example.workutils.biz.mybatisgenerator.application;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class GenerationPlannerTest {
+
+    @TempDir
+    Path tempDir;
+
+    @Test
+    void reportsExistingFilesAndDirectoriesWaitingToBeCreated() throws IOException {
+        Path javaRoot = Files.createDirectories(tempDir.resolve("src/main/java"));
+        Files.writeString(javaRoot.resolve("Account.java"), "class Account {}");
+        Files.writeString(javaRoot.resolve("README.txt"), "ignored");
+        OutputLayout layout = new OutputLayout(
+                tempDir,
+                javaRoot,
+                tempDir.resolve("src/main/resources"),
+                javaRoot);
+
+        GenerationPlan plan = new GenerationPlanner().plan(
+                List.of("account", "trade"), layout);
+
+        assertEquals(List.of("account", "trade"), plan.tables());
+        assertEquals(1, plan.modelRisk().existingFileCount());
+        assertEquals(1, plan.mapperRisk().existingFileCount());
+        assertFalse(plan.xmlRisk().exists());
+        assertTrue(plan.xmlRisk().willCreate());
+    }
+
+    @Test
+    void rejectsAPlanContainingAnUnwritableExistingDirectory() {
+        DirectoryRisk blocked = new DirectoryRisk(
+                tempDir.resolve("blocked"), true, false, false, 0);
+        GenerationPlan plan = new GenerationPlan(
+                List.of("account"), blocked, blocked, blocked);
+
+        assertThrows(IllegalArgumentException.class,
+                plan::validateWritableDirectories);
+    }
+}

src/test/java/com/example/workutils/biz/mybatisgenerator/application/GeneratorRequestTest.java

@@ -1,7 +1,9 @@
 package com.example.workutils.biz.mybatisgenerator.application;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
 
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -10,6 +12,9 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 
 class GeneratorRequestTest {
 
+    @TempDir
+    Path tempDir;
+
     @Test
     void queryRequiresAndTrimsPattern() {
         assertEquals("trade%",
@@ -19,23 +24,22 @@ class GeneratorRequestTest {
     }
 
     @Test
-    void generateCopiesTablesAndDefaultsDirectories() {
+    void generateCopiesTablesAndKeepsOutputLayout() {
         List<String> tables = new ArrayList<>(List.of("trade_order"));
+        OutputLayout layout = new OutputLayoutPolicy().derive(tempDir);
         GenerateArtifactsRequest request = new GenerateArtifactsRequest(
-                tables, " ", null, "./custom");
+                tables, layout);
 
         tables.add("trade_item");
 
         assertEquals(List.of("trade_order"), request.tables());
-        assertEquals("./generator", request.modelDirectory());
+        assertEquals(layout, request.outputLayout());
-        assertEquals("./generator", request.xmlDirectory());
-        assertEquals("./custom", request.mapperDirectory());
     }
 
     @Test
     void generateRequiresSelectedTable() {
         assertThrows(IllegalArgumentException.class,
                 () -> new GenerateArtifactsRequest(
-                        List.of(), "a", "b", "c"));
+                        List.of(), new OutputLayoutPolicy().derive(tempDir)));
     }
 }

src/test/java/com/example/workutils/biz/mybatisgenerator/application/GeneratorUseCaseTest.java

@@ -1,7 +1,10 @@
 package com.example.workutils.biz.mybatisgenerator.application;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
 
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicReference;
@@ -10,6 +13,9 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 
 class GeneratorUseCaseTest {
 
+    @TempDir
+    Path tempDir;
+
     @Test
     void queryDelegatesAndCopiesResult() throws Exception {
         List<String> gatewayResult =
@@ -25,20 +31,27 @@ class GeneratorUseCaseTest {
     }
 
     @Test
-    void generateDelegatesCompleteRequest() throws Exception {
+    void generateDelegatesRequestAndReturnsFileDifference() throws Exception {
         AtomicReference<GenerateArtifactsRequest> received =
                 new AtomicReference<>();
+        OutputLayout layout = new OutputLayoutPolicy().derive(tempDir);
         GenerateArtifactsUseCase useCase =
                 new GenerateArtifactsUseCase(request -> {
                     received.set(request);
+                    Files.createDirectories(request.outputLayout().modelDirectory());
+                    Files.writeString(
+                            request.outputLayout().modelDirectory().resolve("TradeOrder.java"),
+                            "class TradeOrder {}");
                     return "generated";
                 });
         GenerateArtifactsRequest request = new GenerateArtifactsRequest(
-                List.of("trade_order"), "model", "xml", "mapper");
+                List.of("trade_order"), layout);
 
-        String result = useCase.execute(request);
+        GenerationResult result = useCase.execute(request);
 
-        assertEquals("generated", result);
+        assertEquals("generated", result.generatorMessage());
+        assertEquals(List.of(layout.modelDirectory().resolve("TradeOrder.java")),
+                result.createdFiles());
         assertEquals(request, received.get());
     }
 }

src/test/java/com/example/workutils/biz/mybatisgenerator/application/OutputLayoutPolicyTest.java

@@ -0,0 +1,52 @@
+package com.example.workutils.biz.mybatisgenerator.application;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+class OutputLayoutPolicyTest {
+
+    @TempDir
+    Path tempDir;
+
+    @Test
+    void derivesStandardDirectoriesFromProjectRoot() {
+        OutputLayout layout = new OutputLayoutPolicy().derive(tempDir);
+
+        Path root = tempDir.toAbsolutePath().normalize();
+        assertEquals(root, layout.projectRoot());
+        assertEquals(root.resolve("src/main/java"), layout.modelDirectory());
+        assertEquals(root.resolve("src/main/resources"), layout.xmlDirectory());
+        assertEquals(root.resolve("src/main/java"), layout.mapperDirectory());
+    }
+
+    @Test
+    void rejectsARegularFileAsProjectRoot() throws IOException {
+        Path file = Files.createFile(tempDir.resolve("pom.xml"));
+
+        assertThrows(IllegalArgumentException.class,
+                () -> new OutputLayoutPolicy().derive(file));
+    }
+
+    @Test
+    void keepsExplicitCustomDirectories() {
+        OutputLayout layout = new OutputLayoutPolicy().custom(
+                tempDir,
+                tempDir.resolve("model-output"),
+                tempDir.resolve("xml-output"),
+                tempDir.resolve("mapper-output"));
+
+        assertEquals(tempDir.resolve("model-output").toAbsolutePath().normalize(),
+                layout.modelDirectory());
+        assertEquals(tempDir.resolve("xml-output").toAbsolutePath().normalize(),
+                layout.xmlDirectory());
+        assertEquals(tempDir.resolve("mapper-output").toAbsolutePath().normalize(),
+                layout.mapperDirectory());
+    }
+}

src/test/java/com/example/workutils/biz/mybatisgenerator/application/OutputSnapshotTest.java

@@ -0,0 +1,43 @@
+package com.example.workutils.biz.mybatisgenerator.application;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.FileTime;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class OutputSnapshotTest {
+
+    @TempDir
+    Path tempDir;
+
+    @Test
+    void classifiesCreatedUpdatedAndUnchangedFiles() throws IOException {
+        Path javaRoot = Files.createDirectories(tempDir.resolve("src/main/java"));
+        Path xmlRoot = Files.createDirectories(tempDir.resolve("src/main/resources"));
+        Path updated = Files.writeString(javaRoot.resolve("Account.java"), "before");
+        Path unchanged = Files.writeString(xmlRoot.resolve("Account.xml"), "same");
+        OutputLayout layout = new OutputLayout(tempDir, javaRoot, xmlRoot, javaRoot);
+        OutputSnapshot before = OutputSnapshot.capture(layout);
+
+        Files.writeString(updated, "after-content");
+        Files.setLastModifiedTime(updated, FileTime.fromMillis(
+                Files.getLastModifiedTime(updated).toMillis() + 2_000));
+        Path created = Files.writeString(javaRoot.resolve("AccountMapper.java"), "new");
+        OutputSnapshot after = OutputSnapshot.capture(layout);
+
+        GenerationResult result = before.compare(after, "generated");
+
+        assertEquals(java.util.List.of(created.toAbsolutePath().normalize()),
+                result.createdFiles());
+        assertEquals(java.util.List.of(updated.toAbsolutePath().normalize()),
+                result.updatedFiles());
+        assertEquals(java.util.List.of(unchanged.toAbsolutePath().normalize()),
+                result.unchangedFiles());
+        assertEquals("generated", result.generatorMessage());
+    }
+}