Command (emma 2.1.2 API)

java.lang.Object
- com.vladium.emma.Command

直接已知子类:

ctlCommand, instrCommand, mergeCommand, reportCommand, runCommand
```
public abstract class Command
extends Object
```
Base class for all our command line tools (Commands). Commands use the following simple pluggability pattern:
- each concrete Command implementation is expected to be in a class with full Java name prefix.name.nameCommand, where prefix is IAppConstants.APP_PACKAGE and name is the canonical Command name;
- each concrete Command implementation should be a public class with a public constructor with (String, String[]) signature;
- each Command can rely on a usage classpath resource named prefix.name.name_usage.res.
This pattern allows adding new commands (subclasses) without introducing compile time coupling to this base class and its Factory method.
作者:

Vlad Roubtsov, (C) 2003

字段概要

字段
限定符和类型	字段和说明
`protected static String`	`COMMA_DELIMITERS`
`protected String[]`	`m_args`
`protected boolean`	`m_exit`
`protected PrintWriter`	`m_out`
`protected File`	`m_propertyFile`
`protected Properties`	`m_propertyOverrides`
`protected String`	`m_usageCommandName`
`protected static String`	`PATH_DELIMITERS`
`protected static int`	`RC_OK`
`protected static int`	`RC_UNEXPECTED`
`protected static int`	`RC_USAGE`
`protected static int`	`STDOUT_WIDTH`
`protected static String[]`	`USAGE_OPT_NAMES`

构造器概要

构造器
限定符	构造器和说明
`protected`	`Command(String usageName, String[] args)` A public version of this constructor is called by the Factory method `create(String, String, String[])`.

方法概要

所有方法静态方法实例方法抽象方法具体方法
限定符和类型	方法和说明
`static Command`	`create(String name, String usageName, String[] args)` Factory method for Commands.
`protected void`	`exit(boolean showBuildID, String msg, Throwable t, int rc)` A helper method to terminate a Command execution with correct -exit semantics.
`protected String`	`getCanonicalCommandName()` Returns this command's canonical name (e.g, runCommand can be mapped to "emma run" or "emmarun" command line tools but its canonical name is simply "run").
`protected static String[]`	`getListOptValue(IOptsParser.IOpt opt, String delimiters, boolean processAtFiles)` A helper method to convert a command line option to a value list
`protected static boolean`	`getOptionalBooleanOptValue(IOptsParser.IOpt opt)` A helper method to convert a command line option to a boolean.
`protected IOptsParser`	`getOptParser(ClassLoader loader)` Loads the options parser associated with this command.
`protected void`	`processCmdPropertyOverrides(IOptsParser.IOpts parsedopts)` This method processes all -D property overrides specified on the command line.
`protected boolean`	`processFilePropertyOverrides()` This method processes the -properties override if it was specified.
`protected boolean`	`processOpt(IOptsParser.IOpt opt)` A helper method for handling a number of options common to all Commands.
`abstract void`	`run()` Implemented by subclasses to handle this command's unit of work and command line arguments.
`protected abstract String`	`usageArgsMsg()` Implemented by actual Command classes to specify the string that should follow command name prefix when dumping usage.
`protected void`	`usageexit(String msg, IOptsParser parser, int level)` A helper method to emit usage-related messages before a call to `exit(boolean, String, Throwable, int)`.
`protected String`	`usageMsgPrefix()` Returns a prefix used for usage-related error messaging.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 字段详细资料
  - m_usageCommandName
```
protected final String m_usageCommandName
```
  - m_args
```
protected final String[] m_args
```
  - m_out
```
protected final PrintWriter m_out
```
  - m_propertyFile
```
protected File m_propertyFile
```
  - m_propertyOverrides
```
protected Properties m_propertyOverrides
```
  - m_exit
```
protected boolean m_exit
```
  - COMMA_DELIMITERS
```
protected static final String COMMA_DELIMITERS
```
    另请参阅:
    
    常量字段值
  - PATH_DELIMITERS
```
protected static final String PATH_DELIMITERS
```
  - USAGE_OPT_NAMES
```
protected static final String[] USAGE_OPT_NAMES
```
  - STDOUT_WIDTH
```
protected static final int STDOUT_WIDTH
```
    另请参阅:
    
    常量字段值
  - RC_OK
```
protected static final int RC_OK
```
    另请参阅:
    
    常量字段值
  - RC_USAGE
```
protected static final int RC_USAGE
```
    另请参阅:
    
    常量字段值
  - RC_UNEXPECTED
```
protected static final int RC_UNEXPECTED
```
    另请参阅:
    
    常量字段值
- 构造器详细资料
  - Command
```
protected Command(String usageName,
                  String[] args)
```
    A public version of this constructor is called by the Factory method create(String, String, String[]). Subclasses must keep this constructor signature and make it public.
- 方法详细资料
  - create
```
public static Command create(String name,
                             String usageName,
                             String[] args)
```
    Factory method for Commands. See the class javadoc for the pluggability pattern implemented by this method.
    
    参数:
    
    name - canonical command name [may not be null or empty]
    
    usageName - command's usage (as seen on the command line) name [may not be null or empty]
    
    args - command's command line args [null is equivalent to an empty array]
    
    返回:
    
    a new Command instance ready to be run.
    
    抛出:
    
    EMMARuntimeException - if a Command with canonical name 'name' could not be instantiated
  - run
```
public abstract void run()
```
    Implemented by subclasses to handle this command's unit of work and command line arguments. This method may not return because it might call exit(boolean, String, Throwable, int).
  - usageArgsMsg
```
protected abstract String usageArgsMsg()
```
    Implemented by actual Command classes to specify the string that should follow command name prefix when dumping usage. See command classes for examples.
  - getCanonicalCommandName
```
protected final String getCanonicalCommandName()
```
    Returns this command's canonical name (e.g, runCommand can be mapped to "emma run" or "emmarun" command line tools but its canonical name is simply "run"). Note that canonical names are derived from full Java class names according to the pluggability pattern explained in the class javadoc comment.
  - usageMsgPrefix
```
protected final String usageMsgPrefix()
```
    Returns a prefix used for usage-related error messaging. This prefix is derived from the end user command line string for this command (e.g, "emma run" or "emmarun").
  - getOptParser
```
protected final IOptsParser getOptParser(ClassLoader loader)
```
    Loads the options parser associated with this command. The associated usage resource is found using the pluggability pattern explained in the class javadoc comment.
    
    参数:
    
    loader - classloader to use for loading the usage resource [may not be null]
  - processOpt
```
protected final boolean processOpt(IOptsParser.IOpt opt)
```
    A helper method for handling a number of options common to all Commands. Concrete Command classes should call this method first on every option and handle the option themselves only if this method returns 'false'.
    
    参数:
    
    opt - option to handle [may not be null]
    
    返回:
    
    true if 'opt' was recognized and handled
  - processCmdPropertyOverrides
```
protected final void processCmdPropertyOverrides(IOptsParser.IOpts parsedopts)
```
    This method processes all -D property overrides specified on the command line. To ensure that all -D overrides take precedence over all -properties overrides, this method must be called before processFilePropertyOverrides().
    
    参数:
    
    parsedopts - [may not be null]
  - processFilePropertyOverrides
```
protected final boolean processFilePropertyOverrides()
```
    This method processes the -properties override if it was specified. It should be called after all individual options have been handled via a loop that calls processOpt(IOptsParser.IOpt), because that will ensure that m_propertyFile has been set (otherwise, this method is a no-op). To ensure that file overrides have lower priority than named property overrides, this method should be called after processCmdPropertyOverrides(IOptsParser.IOpts).
    This method calls exit(boolean, String, Throwable, int) on any file I/O error.
    
    返回:
    
    false if the file could not be read due to an IOException
  - usageexit
```
protected final void usageexit(String msg,
                               IOptsParser parser,
                               int level)
```
    A helper method to emit usage-related messages before a call to exit(boolean, String, Throwable, int).
    
    参数:
    
    msg - message to precede detailed usage text [if null, no such message is emitted]
    
    parser - options parser instance used to emit detailed usage text [if null, no text is emitted]
    
    level - usage text detail level [@see IOptsParser#usage(PrintWriter, int, int)]
  - exit
```
protected final void exit(boolean showBuildID,
                          String msg,
                          Throwable t,
                          int rc)
                   throws EMMARuntimeException
```
    A helper method to terminate a Command execution with correct -exit semantics. If rc != RC_OK, this message will terminate either by a call to System.exit(rc) or by throwing an exception, depending on m_exit setting.
    
    参数:
    
    showBuildID - flag to indicate that pre-exit message should be prefixed with IAppConstants.APP_USAGE_BUILD_ID
    
    msg - message to precede exit exception stack traces, if any [ignored if null]
    
    t - exit exception [ignored if null, will be wrapped in an EMMARuntimeException if not an instance of that already]
    
    rc - one of RC_xxx constants
    
    抛出:
    
    EMMARuntimeException
  - getOptionalBooleanOptValue
```
protected static boolean getOptionalBooleanOptValue(IOptsParser.IOpt opt)
```
    A helper method to convert a command line option to a boolean.
    
    参数:
    
    opt - [may not be null]
    
    返回:
    
    true if the option has no values [e.g., '-f'] or if its first value evaluates to 'true' according to Property.toBoolean(String).
  - getListOptValue
```
protected static String[] getListOptValue(IOptsParser.IOpt opt,
                                          String delimiters,
                                          boolean processAtFiles)
                                   throws IOException
```
    A helper method to convert a command line option to a value list
    
    参数:
    
    opt - [may not be null]
    
    delimiters - [@see Strings#mergeAT(String[], String, boolean)]
    
    processAtFiles - [@see Strings#mergeAT(String[], String, boolean)]
    
    抛出:
    
    IOException - on any at-file I/O errors

类 Command

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

m_usageCommandName

m_args

m_out

m_propertyFile

m_propertyOverrides

m_exit

COMMA_DELIMITERS

PATH_DELIMITERS

USAGE_OPT_NAMES

STDOUT_WIDTH

RC_OK

RC_USAGE

RC_UNEXPECTED

构造器详细资料

Command

方法详细资料

create

run

usageArgsMsg

getCanonicalCommandName

usageMsgPrefix

getOptParser

processOpt

processCmdPropertyOverrides

processFilePropertyOverrides

usageexit

exit

getOptionalBooleanOptValue

getListOptValue