xbn.programs
Class ReportBadImports

java.lang.Object
  |
  +--xbn.XBNObject
        |
        +--xbn.programs.XBNStatic
              |
              +--xbn.programs.ReportBadImports

public class ReportBadImports

extends XBNStatic

An application to analyze a directory of Java code, reporting on all unneeded/redundant import statements. It detects imports that are not used, duplicate import statements, and also needless self-referencing star ('.*;') imports.

Source code: ReportBadImports.java.

Notes

This application does the same thing as PMD's rulesets/imports.xml ruleset, but has more specific error messages.

This application uses string analysis only, no reflection is involved. Specifically, it searches for the last word in each specific import statement ('AssertException' is the last word in 'import xbn.AssertException;'), to see that it exists elsewhere in the code (ignoring comments). It can tell the difference between 'MyAssertException' and 'AssertException'.

'.*;' import statements (star imports, the opposite of specific imports) are also analyzed for duplicates, and also that the package it is importing is one other than the package in which the containing class exists.

In order for this code to work properly...

This application will only work (as expected!) on Java code that can be successfully compiled.

Although the compiler knows that // contained in a string is not the beginning of a comment, you must denote this with

'/' + '/'

and not

'//'

The same is true with the multi-line comment delimiter:

'/' + '*' and '*' + '/'

instead of

'/*' and '*/'

Why? Because I don't want to have to write complicated string parsing, which can tell the difference between true comment delimiters, and those existing inside strings. :' )

Error codes

Key:

• Self-referencing: This import statement is importing the same package (or a class therein) as the class in which the import statement exists.
• Sub-import (specific only): This specific import is a class already imported by an existing star import. For example, the specific import import java.what.Ever; is a sub-import of import java.what.*;. Import statements that are sub-imports should be deleted.
• Unneeded (specific only): This specific import is unneeded, because it is not referenced anywhere in the code (outside of comments). Unneeded import statements should be deleted.
• Duplicate: This import statement exists at least twice.

Precedence: Duplicate state is always reported. Self-referencing trumps unneeded, and unneeded trumps sub-import. When one error type trumps another, the trumped error condition is not analyzed, and therefore unknown (denoted by a ?).

Code for import type		Error type
Star	Specific	Self-referencing	Unneeded	Sub-import	Duplicate
f	f	Yes	?	?	no
F	F	Yes	?	?	Yes
n/a	i	no	no	Yes	no
n/a	I	no	no	Yes	Yes
n/a	x	no	Yes	?	no
n/a	X	no	Yes	?	Yes
d	d	no	no	no	Yes

Import statements for testing

Adding these import statements into VWChar (right below existing import statements), and then running this application (or PMD) against it, will result in every possible error. There is no need to compile the code.

//To test xbn.programs.ReportBadImports...START
import xbn.array.*;
import xbn.array.*;
import xbn.array.UNNEEDED_and_SUB_IMPORT_and_SELF_REFERENCE;
import xbn.array.UNNEEDED_and_SUB_IMPORT_and_SELF_REFERENCE_and_DUPLICATE;
import xbn.array.UNNEEDED_and_SUB_IMPORT_and_SELF_REFERENCE_and_DUPLICATE;

import java.util.UNNEEDED;

//Duplicate, because of the actual import statement above
//this testing section.
import java.util.Arrays;

import java.util.UNNEEDED_and_DUPLICATE;
import java.util.UNNEEDED_and_DUPLICATE;

//No errors.
import java.bla.*;

import java.bla.UNNEEDED_and_SUB_IMPORT;
import java.bla.UNNEEDED_and_SUB_IMPORT_and_DUPLICATE;
import java.bla.UNNEEDED_and_SUB_IMPORT_and_DUPLICATE;
//To test xbn.programs.ReportBadImports...END

Fields inherited from class xbn.XBNObject

bFALSE_IN_PRODUCTION, bTRUE_IN_PRODUCTION, sCNSTR, sES, sLINE_SEP

Constructor Summary

ReportBadImports()
Create a ReportBadImports.

Method Summary

static void

main(String[] as_cmdLineParams) Run the application.

Methods inherited from class xbn.programs.XBNStatic

throwAXS

Methods inherited from class xbn.XBNObject

getXMsgPrefix, sop, sopl, sopl, throwAX, throwAXIfBadStr, throwAXIfNull, throwAXSpoof

Methods inherited from class java.lang.Object

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

Constructor Detail

ReportBadImports

public ReportBadImports()

Create a ReportBadImports. This constructor does nothing.

Method Detail

main

public static final void main(String[] as_cmdLineParams)

Run the application.