com.vaadin.flow.server.frontend.

java.lang.Object
- com.vaadin.flow.server.frontend.FrontendUtils

```
public class FrontendUtils
extends Object
```
A class for static methods and definitions that might be used in different locations.
For internal use only. May be renamed or removed in a future release.

Since:

2.0

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`FrontendUtils.CommandExecutionException`	Thrown when the command execution fails.
`static class`	`FrontendUtils.UnknownVersionException`	Thrown when detecting the version of a tool fails.

Field Summary

Fields
Modifier and Type	Field	Description
`static String`	`BOOTSTRAP_FILE_NAME`	File name of the bootstrap file that is generated in frontend `GENERATED` folder.
`static String`	`BRIGHT_BLUE`
`static String`	`CHUNKS`	A key in a Json object for chunks list.
`static String`	`CSS_IMPORTS`	A key in a Json object for css imports data.
`static String`	`DEAULT_FLOW_RESOURCES_FOLDER`	Deprecated. This is deprecated due to a typo.
`static String`	`DEFAULT_CONNECT_APPLICATION_PROPERTIES`	Default application properties file path in Vaadin project.
`static String`	`DEFAULT_CONNECT_JAVA_SOURCE_FOLDER`	Default Java source folder for OpenAPI generator.
`static String`	`DEFAULT_CONNECT_OPENAPI_JSON_FILE`	Default generated path for OpenAPI spec file.
`static String`	`DEFAULT_FLOW_RESOURCES_FOLDER`	Default folder where front-end resources present in the classpath jars are copied to.
`static String`	`DEFAULT_FRONTEND_DIR`	Path of the folder containing application frontend source files, it needs to be relative to the `DEFAULT_NODE_DIR` By default it is `/frontend` in the project folder.
`static String`	`DEFAULT_GENERATED_DIR`	Default folder name for flow generated stuff relative to the `InitParameters.BUILD_FOLDER`.
`static String`	`DEFAULT_NODE_DIR`	Default folder for the node related content.
`static String`	`DEFAULT_PROJECT_FRONTEND_GENERATED_DIR`	Default generated path for generated frontend files.
`static String`	`DISABLE_CHECK`
`static String`	`EXPORT_CHUNK`	The entry-point key used for the exported bundle.
`static String`	`FALLBACK`	A key in a Json object for fallback chunk.
`static String`	`FALLBACK_IMPORTS_NAME`	Name of the file that contains all application imports, javascript, theme and style annotations which are not discovered by the current scanning strategy (but they are in the project classpath).
`static String`	`FEATURE_FLAGS_FILE_NAME`	File name of the feature flags file that is generated in frontend `GENERATED` folder.
`static String`	`FLOW_NPM_PACKAGE_NAME`	The npm package name that will be used for the javascript files present in jar resources that will to be copied to the npm folder so as they are accessible to webpack.
`static String`	`FRONTEND`	Default folder used for source and generated folders.
`static String`	`GENERATED`	Default folder for client-side generated files inside the project root frontend folder.
`static String`	`GREEN`
`static String`	`IMPORTS_D_TS_NAME`	The TypeScript definitions for the `IMPORTS_NAME` file.
`static String`	`IMPORTS_NAME`	Name of the file that contains application imports, javascript, theme and style annotations.
`static String`	`INDEX_HTML`	File name of the index.html in client side.
`static String`	`INDEX_JS`	File name of the index.js in client side.
`static String`	`INDEX_TS`	File name of the index.ts in client side.
`static String`	`JS_MODULES`	A key in a Json object for js modules data.
`static String`	`NODE_MODULES`	Location for the installed node packages.
`static String`	`PARAM_FRONTEND_DIR`	A parameter for overriding the `DEFAULT_FRONTEND_DIR` folder.
`static String`	`PARAM_GENERATED_DIR`	A parameter for overriding the `DEFAULT_GENERATED_DIR` folder.
`static String`	`PARAM_IGNORE_VERSION_CHECKS`	Set to `true` to ignore node/npm tool version checks.
`static String`	`PARAM_TOKEN_FILE`	A parameter informing about the location of the `TOKEN_FILE`.
`static String`	`PROJECT_BASEDIR`
`static String`	`RED`
`static String`	`SERVICE_WORKER_SRC`	The name of the service worker source file for InjectManifest method of workbox-webpack-plugin.
`static String`	`SERVICE_WORKER_SRC_JS`	The JavaScript version of the service worker file, for checking if a user has a JavaScript version of a custom service worker file already.
`static String`	`THEME_IMPORTS_D_TS_NAME`
`static String`	`THEME_IMPORTS_NAME`
`static String`	`TOKEN_FILE`	File used to enable npm mode.
`static String`	`VITE_CONFIG`	The name of the vite configuration file.
`static String`	`VITE_DEVMODE_TS`	File name of Vite helper used in development mode.
`static String`	`VITE_GENERATED_CONFIG`	The name of the generated vite configuration file.
`static String`	`WEB_COMPONENT_BOOTSTRAP_FILE_NAME`	File name of the web component bootstrap file that is generated in frontend `GENERATED` folder.
`static String`	`WEB_COMPONENT_HTML`	File name of the web-component.html in client side.
`static String`	`WEBPACK_CONFIG`	The name of the webpack configuration file.
`static String`	`WEBPACK_GENERATED`	The name of the webpack generated configuration file.
`static String`	`WEBPACK_PREFIX_ALIAS`	A special prefix used by webpack to map imports placed in the `DEFAULT_FRONTEND_DIR`.
`static String`	`YELLOW`

Method Summary

All Methods
Modifier and Type	Method	Description
`static void`	`clearCachedStatsContent(VaadinService service)`	Clears the `stats.json` cache within this `VaadinContext`.
`static String`	`commandToString(String baseDir, List<String> command)`	Pretty prints a command line order.
`static void`	`console(String format, Object message)`	Intentionally send to console instead to log, useful when executing external processes.
`static ProcessBuilder`	`createProcessBuilder(List<String> command)`	Creates a process builder for the given list of program and arguments.
`static void`	`deleteDirectory(File directory)`	Recursively delete given directory and contents.
`static void`	`deleteNodeModules(File nodeModules)`	Try to remove the `node_modules` directory, if it exists inside the given base directory.
`static String`	`executeCommand(List<String> command)`	Executes a given command as a native process.
`static InputStream`	`getFrontendFileFromDevModeHandler(VaadinService service, String path)`	Get the contents of a frontend file from the running dev server.
`static String`	`getIndexHtmlContent(VaadinService service)`	Gets the content of the `frontend/index.html` file which is served by webpack or vite in dev-mode and read from classpath in production mode.
`static String`	`getOsName()`	Get the Operating System name from the `os.name` system property.
`static FrontendVersion`	`getPackageVersionFromJson(elemental.json.JsonObject sourceJson, String pkg, String versionOrigin)`	Tries to parse the given package's frontend version or if it doesn't exist, returns `null`.
`static String`	`getProjectFrontendDir(DeploymentConfiguration configuration)`	Get directory where project's frontend files are located.
`static String`	`getStatsAssetsByChunkName(VaadinService service)`	Load the asset chunks from `stats.json`.
`static String`	`getUnixPath(Path source)`	Get path as a String in Unix form.
`static String`	`getUnixRelativePath(Path source, Path target)`	Get relative path from a source path to a target path in Unix form.
`static File`	`getVaadinHomeDirectory()`	Gets vaadin home directory (`".vaadin"` folder in the user home dir).
`protected static FrontendVersion`	`getVersion(String tool, List<String> versionCommand)`
`static String`	`getWebComponentHtmlContent(VaadinService service)`	Gets the content of the `frontend/web-component.html` file which is served by webpack or vite in dev-mode and read from classpath in production mode.
`static boolean`	`isWebpackConfigFile(File file)`	Checks whether the `file` is a webpack configuration file with the expected content (includes a configuration generated by Flow).
`static boolean`	`isWindows()`	Check if the current os is Windows.
`static FrontendVersion`	`parseFrontendVersion(String versionString)`	Parse the version number of node/npm from version output string.
`static FallbackChunk`	`readFallbackChunk(elemental.json.JsonObject object)`	Read fallback chunk data from a json object.
`static File`	`resolveFrontendPath(File projectRoot, String path)`	Looks up the frontend resource at the given path.
`static File`	`resolveFrontendPath(File projectRoot, String path, File frontendDirectory)`	Looks up the fronted resource at the given path.
`static String`	`streamToString(InputStream inputStream)`	Read a stream and copy the content into a String using system line separators for all 'carriage return' characters.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - PROJECT_BASEDIR
```
public static final String PROJECT_BASEDIR
```
    See Also:
    
    Constant Field Values
  - DEFAULT_NODE_DIR
```
public static final String DEFAULT_NODE_DIR
```
    Default folder for the node related content. It's the base directory for Constants.PACKAGE_JSON, WEBPACK_CONFIG, NODE_MODULES. By default it's the project root folder.
    
    See Also:
    
    Constant Field Values
  - NODE_MODULES
```
public static final String NODE_MODULES
```
    Location for the installed node packages. This folder is always considered by node, even though we define extra folders with the NODE_PATH.
    
    See Also:
    
    Constant Field Values
  - FRONTEND
```
public static final String FRONTEND
```
    Default folder used for source and generated folders.
    
    See Also:
    
    Constant Field Values
  - GENERATED
```
public static final String GENERATED
```
    Default folder for client-side generated files inside the project root frontend folder.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_FRONTEND_DIR
```
public static final String DEFAULT_FRONTEND_DIR
```
    Path of the folder containing application frontend source files, it needs to be relative to the DEFAULT_NODE_DIR By default it is /frontend in the project folder.
    
    See Also:
    
    Constant Field Values
  - WEBPACK_CONFIG
```
public static final String WEBPACK_CONFIG
```
    The name of the webpack configuration file.
    
    See Also:
    
    Constant Field Values
  - VITE_CONFIG
```
public static final String VITE_CONFIG
```
    The name of the vite configuration file.
    
    See Also:
    
    Constant Field Values
  - VITE_GENERATED_CONFIG
```
public static final String VITE_GENERATED_CONFIG
```
    The name of the generated vite configuration file.
    
    See Also:
    
    Constant Field Values
  - WEBPACK_GENERATED
```
public static final String WEBPACK_GENERATED
```
    The name of the webpack generated configuration file.
    
    See Also:
    
    Constant Field Values
  - SERVICE_WORKER_SRC
```
public static final String SERVICE_WORKER_SRC
```
    The name of the service worker source file for InjectManifest method of workbox-webpack-plugin.
    
    See Also:
    
    Constant Field Values
  - SERVICE_WORKER_SRC_JS
```
public static final String SERVICE_WORKER_SRC_JS
```
    The JavaScript version of the service worker file, for checking if a user has a JavaScript version of a custom service worker file already.
    
    See Also:
    
    Constant Field Values
  - FLOW_NPM_PACKAGE_NAME
```
public static final String FLOW_NPM_PACKAGE_NAME
```
    The npm package name that will be used for the javascript files present in jar resources that will to be copied to the npm folder so as they are accessible to webpack.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_FLOW_RESOURCES_FOLDER
```
public static final String DEFAULT_FLOW_RESOURCES_FOLDER
```
    Default folder where front-end resources present in the classpath jars are copied to. Relative to the InitParameters.BUILD_FOLDER.
    
    See Also:
    
    Constant Field Values
  - DEAULT_FLOW_RESOURCES_FOLDER
```
@Deprecated
public static final String DEAULT_FLOW_RESOURCES_FOLDER
```
    Deprecated.
    This is deprecated due to a typo. Use DEFAULT_FLOW_RESOURCES_FOLDER instead.
    
    Default folder under build folder for copying front-end resources present in the classpath jars.
    
    See Also:
    
    DEFAULT_FLOW_RESOURCES_FOLDER, Constant Field Values
  - DEFAULT_GENERATED_DIR
```
public static final String DEFAULT_GENERATED_DIR
```
    Default folder name for flow generated stuff relative to the InitParameters.BUILD_FOLDER.
    
    See Also:
    
    Constant Field Values
  - IMPORTS_NAME
```
public static final String IMPORTS_NAME
```
    Name of the file that contains application imports, javascript, theme and style annotations. It is also the entry-point for webpack. It is always generated in the DEFAULT_GENERATED_DIR folder.
    
    See Also:
    
    Constant Field Values
  - IMPORTS_D_TS_NAME
```
public static final String IMPORTS_D_TS_NAME
```
    The TypeScript definitions for the IMPORTS_NAME file.
    
    See Also:
    
    Constant Field Values
  - THEME_IMPORTS_D_TS_NAME
```
public static final String THEME_IMPORTS_D_TS_NAME
```
    See Also:
    
    Constant Field Values
  - THEME_IMPORTS_NAME
```
public static final String THEME_IMPORTS_NAME
```
    See Also:
    
    Constant Field Values
  - BOOTSTRAP_FILE_NAME
```
public static final String BOOTSTRAP_FILE_NAME
```
    File name of the bootstrap file that is generated in frontend GENERATED folder. The bootstrap file is always executed in a Vaadin app.
    
    See Also:
    
    Constant Field Values
  - WEB_COMPONENT_BOOTSTRAP_FILE_NAME
```
public static final String WEB_COMPONENT_BOOTSTRAP_FILE_NAME
```
    File name of the web component bootstrap file that is generated in frontend GENERATED folder. The bootstrap file is always executed in an exported web component.
    
    See Also:
    
    Constant Field Values
  - FEATURE_FLAGS_FILE_NAME
```
public static final String FEATURE_FLAGS_FILE_NAME
```
    File name of the feature flags file that is generated in frontend GENERATED folder. The feature flags file contains code to define feature flags as globals that might be used by Vaadin web components or application code.
    
    See Also:
    
    Constant Field Values
  - INDEX_HTML
```
public static final String INDEX_HTML
```
    File name of the index.html in client side.
    
    See Also:
    
    Constant Field Values
  - WEB_COMPONENT_HTML
```
public static final String WEB_COMPONENT_HTML
```
    File name of the web-component.html in client side.
    
    See Also:
    
    Constant Field Values
  - INDEX_TS
```
public static final String INDEX_TS
```
    File name of the index.ts in client side.
    
    See Also:
    
    Constant Field Values
  - INDEX_JS
```
public static final String INDEX_JS
```
    File name of the index.js in client side.
    
    See Also:
    
    Constant Field Values
  - VITE_DEVMODE_TS
```
public static final String VITE_DEVMODE_TS
```
    File name of Vite helper used in development mode.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_CONNECT_JAVA_SOURCE_FOLDER
```
public static final String DEFAULT_CONNECT_JAVA_SOURCE_FOLDER
```
    Default Java source folder for OpenAPI generator.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_CONNECT_APPLICATION_PROPERTIES
```
public static final String DEFAULT_CONNECT_APPLICATION_PROPERTIES
```
    Default application properties file path in Vaadin project.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_CONNECT_OPENAPI_JSON_FILE
```
public static final String DEFAULT_CONNECT_OPENAPI_JSON_FILE
```
    Default generated path for OpenAPI spec file.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_PROJECT_FRONTEND_GENERATED_DIR
```
public static final String DEFAULT_PROJECT_FRONTEND_GENERATED_DIR
```
    Default generated path for generated frontend files.
    
    See Also:
    
    Constant Field Values
  - FALLBACK_IMPORTS_NAME
```
public static final String FALLBACK_IMPORTS_NAME
```
    Name of the file that contains all application imports, javascript, theme and style annotations which are not discovered by the current scanning strategy (but they are in the project classpath). This file is dynamically imported by the IMPORTS_NAME file. It is always generated in the DEFAULT_GENERATED_DIR folder.
    
    See Also:
    
    Constant Field Values
  - PARAM_GENERATED_DIR
```
public static final String PARAM_GENERATED_DIR
```
    A parameter for overriding the DEFAULT_GENERATED_DIR folder.
    
    See Also:
    
    Constant Field Values
  - PARAM_FRONTEND_DIR
```
public static final String PARAM_FRONTEND_DIR
```
    A parameter for overriding the DEFAULT_FRONTEND_DIR folder.
    
    See Also:
    
    Constant Field Values
  - PARAM_IGNORE_VERSION_CHECKS
```
public static final String PARAM_IGNORE_VERSION_CHECKS
```
    Set to true to ignore node/npm tool version checks.
    
    See Also:
    
    Constant Field Values
  - WEBPACK_PREFIX_ALIAS
```
public static final String WEBPACK_PREFIX_ALIAS
```
    A special prefix used by webpack to map imports placed in the DEFAULT_FRONTEND_DIR. e.g. import 'Frontend/foo.js'; references the filefrontend/foo.js.
    
    See Also:
    
    Constant Field Values
  - TOKEN_FILE
```
public static final String TOKEN_FILE
```
    File used to enable npm mode.
    
    See Also:
    
    Constant Field Values
  - CHUNKS
```
public static final String CHUNKS
```
    A key in a Json object for chunks list.
    
    See Also:
    
    Constant Field Values
  - FALLBACK
```
public static final String FALLBACK
```
    A key in a Json object for fallback chunk.
    
    See Also:
    
    Constant Field Values
  - EXPORT_CHUNK
```
public static final String EXPORT_CHUNK
```
    The entry-point key used for the exported bundle.
    
    See Also:
    
    Constant Field Values
  - CSS_IMPORTS
```
public static final String CSS_IMPORTS
```
    A key in a Json object for css imports data.
    
    See Also:
    
    Constant Field Values
  - JS_MODULES
```
public static final String JS_MODULES
```
    A key in a Json object for js modules data.
    
    See Also:
    
    Constant Field Values
  - PARAM_TOKEN_FILE
```
public static final String PARAM_TOKEN_FILE
```
    A parameter informing about the location of the TOKEN_FILE.
    
    See Also:
    
    Constant Field Values
  - DISABLE_CHECK
```
public static final String DISABLE_CHECK
```
    See Also:
    
    Constant Field Values
  - YELLOW
```
public static final String YELLOW
```
    See Also:
    
    Constant Field Values
  - RED
```
public static final String RED
```
    See Also:
    
    Constant Field Values
  - GREEN
```
public static final String GREEN
```
    See Also:
    
    Constant Field Values
  - BRIGHT_BLUE
```
public static final String BRIGHT_BLUE
```
    See Also:
    
    Constant Field Values
- Method Detail
  - getOsName
```
public static String getOsName()
```
    Get the Operating System name from the os.name system property.
    
    Returns:
    
    operating system name
  - isWindows
```
public static boolean isWindows()
```
    Check if the current os is Windows.
    
    Returns:
    
    true if windows
  - streamToString
```
public static String streamToString(InputStream inputStream)
```
    Read a stream and copy the content into a String using system line separators for all 'carriage return' characters.
    
    Parameters:
    
    inputStream - the input stream
    
    Returns:
    
    the string
  - createProcessBuilder
```
public static ProcessBuilder createProcessBuilder(List<String> command)
```
    Creates a process builder for the given list of program and arguments. If the program is defined as an absolute path, then the directory that contains the program is also appended to PATH so that the it can locate related tools.
    
    Parameters:
    
    command - a list with the program and arguments
    
    Returns:
    
    a configured process builder
  - clearCachedStatsContent
```
public static void clearCachedStatsContent(VaadinService service)
```
    Clears the stats.json cache within this VaadinContext.
    
    Parameters:
    
    service - the vaadin service.
  - getIndexHtmlContent
```
public static String getIndexHtmlContent(VaadinService service)
                                  throws IOException
```
    Gets the content of the frontend/index.html file which is served by webpack or vite in dev-mode and read from classpath in production mode.
    NOTE: In dev mode, the file content is fetched using an http request so that we don't need to have a separate index.html's content watcher. Auto-reloading will work automatically, like other files managed by webpack in `frontend/` folder.
    
    Parameters:
    
    service - the vaadin service
    
    Returns:
    
    the content of the index html file as a string, null if not found.
    
    Throws:
    
    IOException - on error when reading file
  - getWebComponentHtmlContent
```
public static String getWebComponentHtmlContent(VaadinService service)
                                         throws IOException
```
    Gets the content of the frontend/web-component.html file which is served by webpack or vite in dev-mode and read from classpath in production mode.
    NOTE: In dev mode, the file content is fetched using an http request so that we don't need to have a separate web-component.html's content watcher. Auto-reloading will work automatically, like other files managed by webpack in `frontend/` folder.
    
    Parameters:
    
    service - the vaadin service
    
    Returns:
    
    the content of the web-component.html file as a string, null if not found.
    
    Throws:
    
    IOException - on error when reading file
  - getFrontendFileFromDevModeHandler
```
public static InputStream getFrontendFileFromDevModeHandler(VaadinService service,
                                                            String path)
```
    Get the contents of a frontend file from the running dev server.
    
    Parameters:
    
    service - the Vaadin service.
    
    path - the file path.
    
    Returns:
    
    an input stream for reading the file contents; null if there is no such file or the dev server is not running.
  - resolveFrontendPath
```
public static File resolveFrontendPath(File projectRoot,
                                       String path)
```
    Looks up the frontend resource at the given path. If the path starts with ./, first look in projectRoot/frontend, then in projectRoot/node_modules/@vaadin/flow-frontend. If the path does not start with ./, look in node_modules instead.
    
    Parameters:
    
    projectRoot - the project root folder.
    
    path - the file path.
    
    Returns:
    
    an existing File , or null if the file doesn't exist.
  - resolveFrontendPath
```
public static File resolveFrontendPath(File projectRoot,
                                       String path,
                                       File frontendDirectory)
```
    Looks up the fronted resource at the given path. If the path starts with ./, first look in projectRoot/frontendDirectory, then in projectRoot/node_modules/@vaadin/flow-frontend. If the path does not start with ./, look in node_modules instead.
    
    Parameters:
    
    projectRoot - the project root folder.
    
    path - the file path.
    
    frontendDirectory - the frontend directory.
    
    Returns:
    
    an existing File , or null if the file doesn't exist.
  - getStatsAssetsByChunkName
```
public static String getStatsAssetsByChunkName(VaadinService service)
                                        throws IOException
```
    Load the asset chunks from stats.json. We will only read the file until we have reached the assetsByChunkName json and return that as a json object string. Note: The stats.json is cached when external stats is enabled or stats.json is provided from the class path. To clear the cache use clearCachedStatsContent(VaadinService).
    
    Parameters:
    
    service - the Vaadin service.
    
    Returns:
    
    json for assetsByChunkName object in stats.json or null if stats.json not found or content not found.
    
    Throws:
    
    IOException - if an I/O error occurs while creating the input stream.
  - getProjectFrontendDir
```
public static String getProjectFrontendDir(DeploymentConfiguration configuration)
```
    Get directory where project's frontend files are located.
    
    Parameters:
    
    configuration - the current deployment configuration
    
    Returns:
    
    DEFAULT_FRONTEND_DIR or value of PARAM_FRONTEND_DIR if it is set.
  - isWebpackConfigFile
```
public static boolean isWebpackConfigFile(File file)
                                   throws IOException
```
    Checks whether the file is a webpack configuration file with the expected content (includes a configuration generated by Flow).
    
    Parameters:
    
    file - a file to check
    
    Returns:
    
    true iff the file exists and includes a generated configuration
    
    Throws:
    
    IOException - if an I/O error occurs while reading the file
  - getUnixRelativePath
```
public static String getUnixRelativePath(Path source,
                                         Path target)
```
    Get relative path from a source path to a target path in Unix form. All the Windows' path separator will be replaced.
    
    Parameters:
    
    source - the source path
    
    target - the target path
    
    Returns:
    
    unix relative path from source to target
  - getUnixPath
```
public static String getUnixPath(Path source)
```
    Get path as a String in Unix form.
    
    Parameters:
    
    source - path to get
    
    Returns:
    
    path as a String in Unix form.
  - readFallbackChunk
```
public static FallbackChunk readFallbackChunk(elemental.json.JsonObject object)
```
    Read fallback chunk data from a json object.
    
    Parameters:
    
    object - json object to read fallback chunk data
    
    Returns:
    
    a fallback chunk data
  - getVersion
```
protected static FrontendVersion getVersion(String tool,
                                            List<String> versionCommand)
                                     throws FrontendUtils.UnknownVersionException
```
    Throws:
    
    FrontendUtils.UnknownVersionException
  - executeCommand
```
public static String executeCommand(List<String> command)
                             throws FrontendUtils.CommandExecutionException
```
    Executes a given command as a native process.
    
    Parameters:
    
    command - the command to be executed and it's arguments.
    
    Returns:
    
    process output string.
    
    Throws:
    
    FrontendUtils.CommandExecutionException - if the process completes exceptionally.
  - parseFrontendVersion
```
public static FrontendVersion parseFrontendVersion(String versionString)
                                            throws IOException
```
    Parse the version number of node/npm from version output string.
    
    Parameters:
    
    versionString - string containing version output, typically produced by tool --version
    
    Returns:
    
    FrontendVersion of versionString
    
    Throws:
    
    IOException - if parsing fails
  - getVaadinHomeDirectory
```
public static File getVaadinHomeDirectory()
```
    Gets vaadin home directory (".vaadin" folder in the user home dir).
    The directory is created if it's doesn't exist.
    
    Returns:
    
    a vaadin home directory
  - commandToString
```
public static String commandToString(String baseDir,
                                     List<String> command)
```
    Pretty prints a command line order. It split in lines adapting to 80 columns, and allowing copy and paste in console. It also removes the current directory to avoid security issues in log files.
    
    Parameters:
    
    baseDir - the current directory
    
    command - the command and it's arguments
    
    Returns:
    
    the string for printing in logs
  - getPackageVersionFromJson
```
public static FrontendVersion getPackageVersionFromJson(elemental.json.JsonObject sourceJson,
                                                        String pkg,
                                                        String versionOrigin)
```
    Tries to parse the given package's frontend version or if it doesn't exist, returns null. In case the value cannot be parsed, logs an error and returns null.
    
    Parameters:
    
    sourceJson - json object that has the package
    
    pkg - the package name
    
    versionOrigin - origin of the version (like a file), used in error message
    
    Returns:
    
    the frontend version the package or null
  - console
```
public static void console(String format,
                           Object message)
```
    Intentionally send to console instead to log, useful when executing external processes.
    
    Parameters:
    
    format - Format of the line to send to console, it must contain a `%s` outlet for the message
    
    message - the string to show
  - deleteNodeModules
```
public static void deleteNodeModules(File nodeModules)
                              throws IOException
```
    Try to remove the node_modules directory, if it exists inside the given base directory. Note that pnpm uses symlinks internally, so delete utilities that follow symlinks when deleting and/or modifying permissions may not work as intended.
    
    Parameters:
    
    nodeModules - the node_modules directory
    
    Throws:
    
    IOException - on failure to delete any one file, or if the directory name is not node_modules
  - deleteDirectory
```
public static void deleteDirectory(File directory)
                            throws IOException
```
    Recursively delete given directory and contents.
    Will not delete contents of symlink or junction directories, only the link file.
    
    Parameters:
    
    directory - directory to delete
    
    Throws:
    
    IOException - on failure to delete or read any one file

com.vaadin.flow.server.frontend.

Class FrontendUtils

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

PROJECT_BASEDIR

DEFAULT_NODE_DIR

NODE_MODULES

FRONTEND

GENERATED

DEFAULT_FRONTEND_DIR

WEBPACK_CONFIG

VITE_CONFIG

VITE_GENERATED_CONFIG

WEBPACK_GENERATED

SERVICE_WORKER_SRC

SERVICE_WORKER_SRC_JS

FLOW_NPM_PACKAGE_NAME

DEFAULT_FLOW_RESOURCES_FOLDER

DEAULT_FLOW_RESOURCES_FOLDER

DEFAULT_GENERATED_DIR

IMPORTS_NAME

IMPORTS_D_TS_NAME

THEME_IMPORTS_D_TS_NAME

THEME_IMPORTS_NAME

BOOTSTRAP_FILE_NAME

WEB_COMPONENT_BOOTSTRAP_FILE_NAME

FEATURE_FLAGS_FILE_NAME

INDEX_HTML

WEB_COMPONENT_HTML

INDEX_TS

INDEX_JS

VITE_DEVMODE_TS

DEFAULT_CONNECT_JAVA_SOURCE_FOLDER

DEFAULT_CONNECT_APPLICATION_PROPERTIES

DEFAULT_CONNECT_OPENAPI_JSON_FILE

DEFAULT_PROJECT_FRONTEND_GENERATED_DIR

FALLBACK_IMPORTS_NAME

PARAM_GENERATED_DIR

PARAM_FRONTEND_DIR

PARAM_IGNORE_VERSION_CHECKS

WEBPACK_PREFIX_ALIAS

TOKEN_FILE

CHUNKS

FALLBACK

EXPORT_CHUNK

CSS_IMPORTS

JS_MODULES

PARAM_TOKEN_FILE

DISABLE_CHECK

YELLOW

RED

GREEN

BRIGHT_BLUE

Method Detail

getOsName

isWindows

streamToString

createProcessBuilder

clearCachedStatsContent

getIndexHtmlContent

getWebComponentHtmlContent

getFrontendFileFromDevModeHandler

resolveFrontendPath

resolveFrontendPath

getStatsAssetsByChunkName

getProjectFrontendDir

isWebpackConfigFile

getUnixRelativePath

getUnixPath

readFallbackChunk

getVersion

executeCommand

parseFrontendVersion

getVaadinHomeDirectory

commandToString

getPackageVersionFromJson

console