Package org.plumelib.bcelutil

Class SimpleLog

java.lang.Object
org.plumelib.bcelutil.SimpleLog
public final class SimpleLog extends Object
A logging class with the following features.
  • Can be enabled and disabled (when disabled, all operations are no-ops),
  • Can indent/exdent log output,
  • Writes to a file or to standard output, and
  • Can provide a stack trace.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    boolean
    enabled
    If false, do no output.
    private @Nullable String
    filename
    The file for logging output.
    private static final String
    INDENT_STR_ONE_LEVEL
    Indentation string for one level of indentation.
    private int
    indentLevel
    The current indentation level.
    private @Nullable String
    indentString
    Cache for the current indentation string, or null if needs to be recomputed.
    private List<String>
    indentStrings
    Cache of indentation strings that have been computed so far.
    private @MonotonicNonNull PrintStream
    logfile
    Where to write logging output.

  • Constructor Summary

    Constructors
    Constructor
    Description
    SimpleLog()
    Create a new SimpleLog object with logging to standard out enabled.
    SimpleLog(boolean enabled)
    Create a new SimpleLog object with logging to standard out.
    SimpleLog(@Nullable String filename)
    Create a new SimpleLog object with logging to a file enabled.
    SimpleLog(@Nullable String filename, boolean enabled)
    Create a new SimpleLog object with logging to a file.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    enabled()
    Return whether logging is enabled.
    void
    exdent()
    Decreases indentation by one level.
    private String
    getIndentString()
    Return the current indentation string.
    void
    indent()
    Increases indentation by one level.
    void
    log(String format, @Nullable Object... args)
    Log a message.
    void
    logStackTrace()
    Print a stack trace to the log.
    void
    resetIndent()
    Resets indentation to none.
    private void
    setLogfile()
    Set the private field logfile (if it is not set), based on the private field filename.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • enabled

      public boolean enabled
      If false, do no output.

    • logfile

      private @MonotonicNonNull PrintStream logfile
      Where to write logging output. Null if nothing has been output yet.

    • filename

      private @Nullable String filename
      The file for logging output. If null, System.out is used.

    • indentLevel

      private int indentLevel
      The current indentation level.

    • INDENT_STR_ONE_LEVEL

      private static final String INDENT_STR_ONE_LEVEL
      Indentation string for one level of indentation.
      See Also:

    • indentString

      private @Nullable String indentString
      Cache for the current indentation string, or null if needs to be recomputed. Never access this directly; always call getIndentString().

    • indentStrings

      private List<String> indentStrings
      Cache of indentation strings that have been computed so far.

  • Constructor Details

    • SimpleLog

      public SimpleLog()
      Create a new SimpleLog object with logging to standard out enabled.

    • SimpleLog

      public SimpleLog(boolean enabled)
      Create a new SimpleLog object with logging to standard out.
      Parameters:
      enabled - whether the logger starts out enabled

    • SimpleLog

      public SimpleLog(@Nullable String filename)
      Create a new SimpleLog object with logging to a file enabled.
      Parameters:
      filename - file name, or use "-" or null for System.out

    • SimpleLog

      public SimpleLog(@Nullable String filename, boolean enabled)
      Create a new SimpleLog object with logging to a file.
      Parameters:
      filename - file name, or use "-" or null for System.out
      enabled - whether the logger starts out enabled

  • Method Details

    • enabled

      public boolean enabled()
      Return whether logging is enabled.
      Returns:
      whether logging is enabled

    • setLogfile

      @EnsuresNonNull("logfile") private void setLogfile()
      Set the private field logfile (if it is not set), based on the private field filename.

      This creates the file if it does not exist. This should be called lazily, when output is performed. Otherwise, it would be annoying to create a zero-size logfile if no output is ever written.

    • log

      @FormatMethod public void log(String format, @Nullable Object... args)
      Log a message. The message is prepended with the current indentation string. The indentation is only applied at the start of the message, not for every line break within the message.
      Parameters:
      format - format string for message
      args - values to be substituted into format

    • logStackTrace

      public void logStackTrace()
      Print a stack trace to the log.

    • getIndentString

      private String getIndentString()
      Return the current indentation string.
      Returns:
      the current indentation string

    • indent

      public void indent()
      Increases indentation by one level.

    • exdent

      public void exdent()
      Decreases indentation by one level.

    • resetIndent

      public void resetIndent()
      Resets indentation to none. Has no effect if logging is disabled.