CustomImportOrderCheck.java
///////////////////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
// Copyright (C) 2001-2024 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
///////////////////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.imports;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.StringTokenizer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.FullIdent;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
/**
* <p>
* Checks that the groups of import declarations appear in the order specified
* by the user. If there is an import but its group is not specified in the
* configuration such an import should be placed at the end of the import list.
* </p>
* <p>
* The rule consists of:
* </p>
* <ol>
* <li>
* STATIC group. This group sets the ordering of static imports.
* </li>
* <li>
* SAME_PACKAGE(n) group. This group sets the ordering of the same package imports.
* Imports are considered on SAME_PACKAGE group if <b>n</b> first domains in package
* name and import name are identical:
* <pre>
* package java.util.concurrent.locks;
*
* import java.io.File;
* import java.util.*; //#1
* import java.util.List; //#2
* import java.util.StringTokenizer; //#3
* import java.util.concurrent.*; //#4
* import java.util.concurrent.AbstractExecutorService; //#5
* import java.util.concurrent.locks.LockSupport; //#6
* import java.util.regex.Pattern; //#7
* import java.util.regex.Matcher; //#8
* </pre>
* If we have SAME_PACKAGE(3) on configuration file, imports #4-6 will be considered as
* a SAME_PACKAGE group (java.util.concurrent.*, java.util.concurrent.AbstractExecutorService,
* java.util.concurrent.locks.LockSupport). SAME_PACKAGE(2) will include #1-8.
* SAME_PACKAGE(4) will include only #6. SAME_PACKAGE(5) will result in no imports assigned
* to SAME_PACKAGE group because actual package java.util.concurrent.locks has only 4 domains.
* </li>
* <li>
* THIRD_PARTY_PACKAGE group. This group sets ordering of third party imports.
* Third party imports are all imports except STATIC, SAME_PACKAGE(n), STANDARD_JAVA_PACKAGE and
* SPECIAL_IMPORTS.
* </li>
* <li>
* STANDARD_JAVA_PACKAGE group. By default, this group sets ordering of standard java/javax imports.
* </li>
* <li>
* SPECIAL_IMPORTS group. This group may contain some imports that have particular meaning for the
* user.
* </li>
* </ol>
* <p>
* Rules are configured as a comma-separated ordered list.
* </p>
* <p>
* Note: '###' group separator is deprecated (in favor of a comma-separated list),
* but is currently supported for backward compatibility.
* </p>
* <p>
* To set RegExps for THIRD_PARTY_PACKAGE and STANDARD_JAVA_PACKAGE groups use
* thirdPartyPackageRegExp and standardPackageRegExp options.
* </p>
* <p>
* Pretty often one import can match more than one group. For example, static import from standard
* package or regular expressions are configured to allow one import match multiple groups.
* In this case, group will be assigned according to priorities:
* </p>
* <ol>
* <li>
* STATIC has top priority
* </li>
* <li>
* SAME_PACKAGE has second priority
* </li>
* <li>
* STANDARD_JAVA_PACKAGE and SPECIAL_IMPORTS will compete using "best match" rule: longer
* matching substring wins; in case of the same length, lower position of matching substring
* wins; if position is the same, order of rules in configuration solves the puzzle.
* </li>
* <li>
* THIRD_PARTY has the least priority
* </li>
* </ol>
* <p>
* Few examples to illustrate "best match":
* </p>
* <p>
* 1. patterns STANDARD_JAVA_PACKAGE = "Check", SPECIAL_IMPORTS="ImportOrderCheck" and input file:
* </p>
* <pre>
* import com.puppycrawl.tools.checkstyle.checks.imports.CustomImportOrderCheck;
* import com.puppycrawl.tools.checkstyle.checks.imports.ImportOrderCheck;
* </pre>
* <p>
* Result: imports will be assigned to SPECIAL_IMPORTS, because matching substring length is 16.
* Matching substring for STANDARD_JAVA_PACKAGE is 5.
* </p>
* <p>
* 2. patterns STANDARD_JAVA_PACKAGE = "Check", SPECIAL_IMPORTS="Avoid" and file:
* </p>
* <pre>
* import com.puppycrawl.tools.checkstyle.checks.imports.AvoidStarImportCheck;
* </pre>
* <p>
* Result: import will be assigned to SPECIAL_IMPORTS. Matching substring length is 5 for both
* patterns. However, "Avoid" position is lower than "Check" position.
* </p>
* <ul>
* <li>
* Property {@code customImportOrderRules} - Specify ordered list of import groups.
* Type is {@code java.lang.String[]}.
* Default value is {@code ""}.
* </li>
* <li>
* Property {@code separateLineBetweenGroups} - Force empty line separator between
* import groups.
* Type is {@code boolean}.
* Default value is {@code true}.
* </li>
* <li>
* Property {@code sortImportsInGroupAlphabetically} - Force grouping alphabetically,
* in <a href="https://en.wikipedia.org/wiki/ASCII#Order">ASCII sort order</a>.
* Type is {@code boolean}.
* Default value is {@code false}.
* </li>
* <li>
* Property {@code specialImportsRegExp} - Specify RegExp for SPECIAL_IMPORTS group imports.
* Type is {@code java.util.regex.Pattern}.
* Default value is {@code "^$"}.
* </li>
* <li>
* Property {@code standardPackageRegExp} - Specify RegExp for STANDARD_JAVA_PACKAGE group imports.
* Type is {@code java.util.regex.Pattern}.
* Default value is {@code "^(java|javax)\."}.
* </li>
* <li>
* Property {@code thirdPartyPackageRegExp} - Specify RegExp for THIRD_PARTY_PACKAGE group imports.
* Type is {@code java.util.regex.Pattern}.
* Default value is {@code ".*"}.
* </li>
* </ul>
* <p>
* Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
* </p>
* <p>
* Violation Message Keys:
* </p>
* <ul>
* <li>
* {@code custom.import.order}
* </li>
* <li>
* {@code custom.import.order.lex}
* </li>
* <li>
* {@code custom.import.order.line.separator}
* </li>
* <li>
* {@code custom.import.order.nonGroup.expected}
* </li>
* <li>
* {@code custom.import.order.nonGroup.import}
* </li>
* <li>
* {@code custom.import.order.separated.internally}
* </li>
* </ul>
*
* @since 5.8
*/
@FileStatefulCheck
public class CustomImportOrderCheck extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_LINE_SEPARATOR = "custom.import.order.line.separator";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_SEPARATED_IN_GROUP = "custom.import.order.separated.internally";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_LEX = "custom.import.order.lex";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_NONGROUP_IMPORT = "custom.import.order.nonGroup.import";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_NONGROUP_EXPECTED = "custom.import.order.nonGroup.expected";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_ORDER = "custom.import.order";
/** STATIC group name. */
public static final String STATIC_RULE_GROUP = "STATIC";
/** SAME_PACKAGE group name. */
public static final String SAME_PACKAGE_RULE_GROUP = "SAME_PACKAGE";
/** THIRD_PARTY_PACKAGE group name. */
public static final String THIRD_PARTY_PACKAGE_RULE_GROUP = "THIRD_PARTY_PACKAGE";
/** STANDARD_JAVA_PACKAGE group name. */
public static final String STANDARD_JAVA_PACKAGE_RULE_GROUP = "STANDARD_JAVA_PACKAGE";
/** SPECIAL_IMPORTS group name. */
public static final String SPECIAL_IMPORTS_RULE_GROUP = "SPECIAL_IMPORTS";
/** NON_GROUP group name. */
private static final String NON_GROUP_RULE_GROUP = "NOT_ASSIGNED_TO_ANY_GROUP";
/** Pattern used to separate groups of imports. */
private static final Pattern GROUP_SEPARATOR_PATTERN = Pattern.compile("\\s*###\\s*");
/** Specify ordered list of import groups. */
private final List<String> customImportOrderRules = new ArrayList<>();
/** Contains objects with import attributes. */
private final List<ImportDetails> importToGroupList = new ArrayList<>();
/** Specify RegExp for SAME_PACKAGE group imports. */
private String samePackageDomainsRegExp = "";
/** Specify RegExp for STANDARD_JAVA_PACKAGE group imports. */
private Pattern standardPackageRegExp = Pattern.compile("^(java|javax)\\.");
/** Specify RegExp for THIRD_PARTY_PACKAGE group imports. */
private Pattern thirdPartyPackageRegExp = Pattern.compile(".*");
/** Specify RegExp for SPECIAL_IMPORTS group imports. */
private Pattern specialImportsRegExp = Pattern.compile("^$");
/** Force empty line separator between import groups. */
private boolean separateLineBetweenGroups = true;
/**
* Force grouping alphabetically,
* in <a href="https://en.wikipedia.org/wiki/ASCII#Order"> ASCII sort order</a>.
*/
private boolean sortImportsInGroupAlphabetically;
/** Number of first domains for SAME_PACKAGE group. */
private int samePackageMatchingDepth;
/**
* Setter to specify RegExp for STANDARD_JAVA_PACKAGE group imports.
*
* @param regexp
* user value.
* @since 5.8
*/
public final void setStandardPackageRegExp(Pattern regexp) {
standardPackageRegExp = regexp;
}
/**
* Setter to specify RegExp for THIRD_PARTY_PACKAGE group imports.
*
* @param regexp
* user value.
* @since 5.8
*/
public final void setThirdPartyPackageRegExp(Pattern regexp) {
thirdPartyPackageRegExp = regexp;
}
/**
* Setter to specify RegExp for SPECIAL_IMPORTS group imports.
*
* @param regexp
* user value.
* @since 5.8
*/
public final void setSpecialImportsRegExp(Pattern regexp) {
specialImportsRegExp = regexp;
}
/**
* Setter to force empty line separator between import groups.
*
* @param value
* user value.
* @since 5.8
*/
public final void setSeparateLineBetweenGroups(boolean value) {
separateLineBetweenGroups = value;
}
/**
* Setter to force grouping alphabetically, in
* <a href="https://en.wikipedia.org/wiki/ASCII#Order">ASCII sort order</a>.
*
* @param value
* user value.
* @since 5.8
*/
public final void setSortImportsInGroupAlphabetically(boolean value) {
sortImportsInGroupAlphabetically = value;
}
/**
* Setter to specify ordered list of import groups.
*
* @param rules
* user value.
* @since 5.8
*/
public final void setCustomImportOrderRules(String... rules) {
Arrays.stream(rules)
.map(GROUP_SEPARATOR_PATTERN::split)
.flatMap(Arrays::stream)
.forEach(this::addRulesToList);
customImportOrderRules.add(NON_GROUP_RULE_GROUP);
}
@Override
public int[] getDefaultTokens() {
return getRequiredTokens();
}
@Override
public int[] getAcceptableTokens() {
return getRequiredTokens();
}
@Override
public int[] getRequiredTokens() {
return new int[] {
TokenTypes.IMPORT,
TokenTypes.STATIC_IMPORT,
TokenTypes.PACKAGE_DEF,
};
}
@Override
public void beginTree(DetailAST rootAST) {
importToGroupList.clear();
}
@Override
public void visitToken(DetailAST ast) {
if (ast.getType() == TokenTypes.PACKAGE_DEF) {
samePackageDomainsRegExp = createSamePackageRegexp(
samePackageMatchingDepth, ast);
}
else {
final String importFullPath = getFullImportIdent(ast);
final boolean isStatic = ast.getType() == TokenTypes.STATIC_IMPORT;
importToGroupList.add(new ImportDetails(importFullPath,
getImportGroup(isStatic, importFullPath), isStatic, ast));
}
}
@Override
public void finishTree(DetailAST rootAST) {
if (!importToGroupList.isEmpty()) {
finishImportList();
}
}
/** Examine the order of all the imports and log any violations. */
private void finishImportList() {
String currentGroup = getFirstGroup();
int currentGroupNumber = customImportOrderRules.lastIndexOf(currentGroup);
ImportDetails previousImportObjectFromCurrentGroup = null;
String previousImportFromCurrentGroup = null;
for (ImportDetails importObject : importToGroupList) {
final String importGroup = importObject.getImportGroup();
final String fullImportIdent = importObject.getImportFullPath();
if (importGroup.equals(currentGroup)) {
validateExtraEmptyLine(previousImportObjectFromCurrentGroup,
importObject, fullImportIdent);
if (isAlphabeticalOrderBroken(previousImportFromCurrentGroup, fullImportIdent)) {
log(importObject.getImportAST(), MSG_LEX,
fullImportIdent, previousImportFromCurrentGroup);
}
else {
previousImportFromCurrentGroup = fullImportIdent;
}
previousImportObjectFromCurrentGroup = importObject;
}
else {
// not the last group, last one is always NON_GROUP
if (customImportOrderRules.size() > currentGroupNumber + 1) {
final String nextGroup = getNextImportGroup(currentGroupNumber + 1);
if (importGroup.equals(nextGroup)) {
validateMissedEmptyLine(previousImportObjectFromCurrentGroup,
importObject, fullImportIdent);
currentGroup = nextGroup;
currentGroupNumber = customImportOrderRules.lastIndexOf(nextGroup);
previousImportFromCurrentGroup = fullImportIdent;
}
else {
logWrongImportGroupOrder(importObject.getImportAST(),
importGroup, nextGroup, fullImportIdent);
}
previousImportObjectFromCurrentGroup = importObject;
}
else {
logWrongImportGroupOrder(importObject.getImportAST(),
importGroup, currentGroup, fullImportIdent);
}
}
}
}
/**
* Log violation if empty line is missed.
*
* @param previousImport previous import from current group.
* @param importObject current import.
* @param fullImportIdent full import identifier.
*/
private void validateMissedEmptyLine(ImportDetails previousImport,
ImportDetails importObject, String fullImportIdent) {
if (isEmptyLineMissed(previousImport, importObject)) {
log(importObject.getImportAST(), MSG_LINE_SEPARATOR, fullImportIdent);
}
}
/**
* Log violation if extra empty line is present.
*
* @param previousImport previous import from current group.
* @param importObject current import.
* @param fullImportIdent full import identifier.
*/
private void validateExtraEmptyLine(ImportDetails previousImport,
ImportDetails importObject, String fullImportIdent) {
if (isSeparatedByExtraEmptyLine(previousImport, importObject)) {
log(importObject.getImportAST(), MSG_SEPARATED_IN_GROUP, fullImportIdent);
}
}
/**
* Get first import group.
*
* @return
* first import group of file.
*/
private String getFirstGroup() {
final ImportDetails firstImport = importToGroupList.get(0);
return getImportGroup(firstImport.isStaticImport(),
firstImport.getImportFullPath());
}
/**
* Examine alphabetical order of imports.
*
* @param previousImport
* previous import of current group.
* @param currentImport
* current import.
* @return
* true, if previous and current import are not in alphabetical order.
*/
private boolean isAlphabeticalOrderBroken(String previousImport,
String currentImport) {
return sortImportsInGroupAlphabetically
&& previousImport != null
&& compareImports(currentImport, previousImport) < 0;
}
/**
* Examine empty lines between groups.
*
* @param previousImportObject
* previous import in current group.
* @param currentImportObject
* current import.
* @return
* true, if current import NOT separated from previous import by empty line.
*/
private boolean isEmptyLineMissed(ImportDetails previousImportObject,
ImportDetails currentImportObject) {
return separateLineBetweenGroups
&& getCountOfEmptyLinesBetween(
previousImportObject.getEndLineNumber(),
currentImportObject.getStartLineNumber()) != 1;
}
/**
* Examine that imports separated by more than one empty line.
*
* @param previousImportObject
* previous import in current group.
* @param currentImportObject
* current import.
* @return
* true, if current import separated from previous by more than one empty line.
*/
private boolean isSeparatedByExtraEmptyLine(ImportDetails previousImportObject,
ImportDetails currentImportObject) {
return previousImportObject != null
&& getCountOfEmptyLinesBetween(
previousImportObject.getEndLineNumber(),
currentImportObject.getStartLineNumber()) > 0;
}
/**
* Log wrong import group order.
*
* @param importAST
* import ast.
* @param importGroup
* import group.
* @param currentGroupNumber
* current group number we are checking.
* @param fullImportIdent
* full import name.
*/
private void logWrongImportGroupOrder(DetailAST importAST, String importGroup,
String currentGroupNumber, String fullImportIdent) {
if (NON_GROUP_RULE_GROUP.equals(importGroup)) {
log(importAST, MSG_NONGROUP_IMPORT, fullImportIdent);
}
else if (NON_GROUP_RULE_GROUP.equals(currentGroupNumber)) {
log(importAST, MSG_NONGROUP_EXPECTED, importGroup, fullImportIdent);
}
else {
log(importAST, MSG_ORDER, importGroup, currentGroupNumber, fullImportIdent);
}
}
/**
* Get next import group.
*
* @param currentGroupNumber
* current group number.
* @return
* next import group.
*/
private String getNextImportGroup(int currentGroupNumber) {
int nextGroupNumber = currentGroupNumber;
while (customImportOrderRules.size() > nextGroupNumber + 1) {
if (hasAnyImportInCurrentGroup(customImportOrderRules.get(nextGroupNumber))) {
break;
}
nextGroupNumber++;
}
return customImportOrderRules.get(nextGroupNumber);
}
/**
* Checks if current group contains any import.
*
* @param currentGroup
* current group.
* @return
* true, if current group contains at least one import.
*/
private boolean hasAnyImportInCurrentGroup(String currentGroup) {
boolean result = false;
for (ImportDetails currentImport : importToGroupList) {
if (currentGroup.equals(currentImport.getImportGroup())) {
result = true;
break;
}
}
return result;
}
/**
* Get import valid group.
*
* @param isStatic
* is static import.
* @param importPath
* full import path.
* @return import valid group.
*/
private String getImportGroup(boolean isStatic, String importPath) {
RuleMatchForImport bestMatch = new RuleMatchForImport(NON_GROUP_RULE_GROUP, 0, 0);
if (isStatic && customImportOrderRules.contains(STATIC_RULE_GROUP)) {
bestMatch.group = STATIC_RULE_GROUP;
bestMatch.matchLength = importPath.length();
}
else if (customImportOrderRules.contains(SAME_PACKAGE_RULE_GROUP)) {
final String importPathTrimmedToSamePackageDepth =
getFirstDomainsFromIdent(samePackageMatchingDepth, importPath);
if (samePackageDomainsRegExp.equals(importPathTrimmedToSamePackageDepth)) {
bestMatch.group = SAME_PACKAGE_RULE_GROUP;
bestMatch.matchLength = importPath.length();
}
}
for (String group : customImportOrderRules) {
if (STANDARD_JAVA_PACKAGE_RULE_GROUP.equals(group)) {
bestMatch = findBetterPatternMatch(importPath,
STANDARD_JAVA_PACKAGE_RULE_GROUP, standardPackageRegExp, bestMatch);
}
if (SPECIAL_IMPORTS_RULE_GROUP.equals(group)) {
bestMatch = findBetterPatternMatch(importPath,
group, specialImportsRegExp, bestMatch);
}
}
if (NON_GROUP_RULE_GROUP.equals(bestMatch.group)
&& customImportOrderRules.contains(THIRD_PARTY_PACKAGE_RULE_GROUP)
&& thirdPartyPackageRegExp.matcher(importPath).find()) {
bestMatch.group = THIRD_PARTY_PACKAGE_RULE_GROUP;
}
return bestMatch.group;
}
/**
* Tries to find better matching regular expression:
* longer matching substring wins; in case of the same length,
* lower position of matching substring wins.
*
* @param importPath
* Full import identifier
* @param group
* Import group we are trying to assign the import
* @param regExp
* Regular expression for import group
* @param currentBestMatch
* object with currently best match
* @return better match (if found) or the same (currentBestMatch)
*/
private static RuleMatchForImport findBetterPatternMatch(String importPath, String group,
Pattern regExp, RuleMatchForImport currentBestMatch) {
RuleMatchForImport betterMatchCandidate = currentBestMatch;
final Matcher matcher = regExp.matcher(importPath);
while (matcher.find()) {
final int matchStart = matcher.start();
final int length = matcher.end() - matchStart;
if (length > betterMatchCandidate.matchLength
|| length == betterMatchCandidate.matchLength
&& matchStart < betterMatchCandidate.matchPosition) {
betterMatchCandidate = new RuleMatchForImport(group, length, matchStart);
}
}
return betterMatchCandidate;
}
/**
* Checks compare two import paths.
*
* @param import1
* current import.
* @param import2
* previous import.
* @return a negative integer, zero, or a positive integer as the
* specified String is greater than, equal to, or less
* than this String, ignoring case considerations.
*/
private static int compareImports(String import1, String import2) {
int result = 0;
final String separator = "\\.";
final String[] import1Tokens = import1.split(separator);
final String[] import2Tokens = import2.split(separator);
for (int i = 0; i != import1Tokens.length && i != import2Tokens.length; i++) {
final String import1Token = import1Tokens[i];
final String import2Token = import2Tokens[i];
result = import1Token.compareTo(import2Token);
if (result != 0) {
break;
}
}
if (result == 0) {
result = Integer.compare(import1Tokens.length, import2Tokens.length);
}
return result;
}
/**
* Counts empty lines between given parameters.
*
* @param fromLineNo
* One-based line number of previous import.
* @param toLineNo
* One-based line number of current import.
* @return count of empty lines between given parameters, exclusive,
* eg., (fromLineNo, toLineNo).
*/
private int getCountOfEmptyLinesBetween(int fromLineNo, int toLineNo) {
int result = 0;
final String[] lines = getLines();
for (int i = fromLineNo + 1; i <= toLineNo - 1; i++) {
// "- 1" because the numbering is one-based
if (CommonUtil.isBlank(lines[i - 1])) {
result++;
}
}
return result;
}
/**
* Forms import full path.
*
* @param token
* current token.
* @return full path or null.
*/
private static String getFullImportIdent(DetailAST token) {
String ident = "";
if (token != null) {
ident = FullIdent.createFullIdent(token.findFirstToken(TokenTypes.DOT)).getText();
}
return ident;
}
/**
* Parses ordering rule and adds it to the list with rules.
*
* @param ruleStr
* String with rule.
* @throws IllegalArgumentException when SAME_PACKAGE rule parameter is not positive integer
* @throws IllegalStateException when ruleStr is unexpected value
*/
private void addRulesToList(String ruleStr) {
if (STATIC_RULE_GROUP.equals(ruleStr)
|| THIRD_PARTY_PACKAGE_RULE_GROUP.equals(ruleStr)
|| STANDARD_JAVA_PACKAGE_RULE_GROUP.equals(ruleStr)
|| SPECIAL_IMPORTS_RULE_GROUP.equals(ruleStr)) {
customImportOrderRules.add(ruleStr);
}
else if (ruleStr.startsWith(SAME_PACKAGE_RULE_GROUP)) {
final String rule = ruleStr.substring(ruleStr.indexOf('(') + 1,
ruleStr.indexOf(')'));
samePackageMatchingDepth = Integer.parseInt(rule);
if (samePackageMatchingDepth <= 0) {
throw new IllegalArgumentException(
"SAME_PACKAGE rule parameter should be positive integer: " + ruleStr);
}
customImportOrderRules.add(SAME_PACKAGE_RULE_GROUP);
}
else {
throw new IllegalStateException("Unexpected rule: " + ruleStr);
}
}
/**
* Creates samePackageDomainsRegExp of the first package domains.
*
* @param firstPackageDomainsCount
* number of first package domains.
* @param packageNode
* package node.
* @return same package regexp.
*/
private static String createSamePackageRegexp(int firstPackageDomainsCount,
DetailAST packageNode) {
final String packageFullPath = getFullImportIdent(packageNode);
return getFirstDomainsFromIdent(firstPackageDomainsCount, packageFullPath);
}
/**
* Extracts defined amount of domains from the left side of package/import identifier.
*
* @param firstPackageDomainsCount
* number of first package domains.
* @param packageFullPath
* full identifier containing path to package or imported object.
* @return String with defined amount of domains or full identifier
* (if full identifier had less domain than specified)
*/
private static String getFirstDomainsFromIdent(
final int firstPackageDomainsCount, final String packageFullPath) {
final StringBuilder builder = new StringBuilder(256);
final StringTokenizer tokens = new StringTokenizer(packageFullPath, ".");
int count = firstPackageDomainsCount;
while (count > 0 && tokens.hasMoreTokens()) {
builder.append(tokens.nextToken());
count--;
}
return builder.toString();
}
/**
* Contains import attributes as line number, import full path, import
* group.
*/
private static final class ImportDetails {
/** Import full path. */
private final String importFullPath;
/** Import group. */
private final String importGroup;
/** Is static import. */
private final boolean staticImport;
/** Import AST. */
private final DetailAST importAST;
/**
* Initialise importFullPath, importGroup, staticImport, importAST.
*
* @param importFullPath
* import full path.
* @param importGroup
* import group.
* @param staticImport
* if import is static.
* @param importAST
* import ast
*/
private ImportDetails(String importFullPath, String importGroup, boolean staticImport,
DetailAST importAST) {
this.importFullPath = importFullPath;
this.importGroup = importGroup;
this.staticImport = staticImport;
this.importAST = importAST;
}
/**
* Get import full path variable.
*
* @return import full path variable.
*/
public String getImportFullPath() {
return importFullPath;
}
/**
* Get import start line number from ast.
*
* @return import start line from ast.
*/
public int getStartLineNumber() {
return importAST.getLineNo();
}
/**
* Get import end line number from ast.
* <p>
* <b>Note:</b> It can be different from <b>startLineNumber</b> when import statement span
* multiple lines.
* </p>
*
* @return import end line from ast.
*/
public int getEndLineNumber() {
return importAST.getLastChild().getLineNo();
}
/**
* Get import group.
*
* @return import group.
*/
public String getImportGroup() {
return importGroup;
}
/**
* Checks if import is static.
*
* @return true, if import is static.
*/
public boolean isStaticImport() {
return staticImport;
}
/**
* Get import ast.
*
* @return import ast.
*/
public DetailAST getImportAST() {
return importAST;
}
}
/**
* Contains matching attributes assisting in definition of "best matching"
* group for import.
*/
private static final class RuleMatchForImport {
/** Position of matching string for current best match. */
private final int matchPosition;
/** Length of matching string for current best match. */
private int matchLength;
/** Import group for current best match. */
private String group;
/**
* Constructor to initialize the fields.
*
* @param group
* Matched group.
* @param length
* Matching length.
* @param position
* Matching position.
*/
private RuleMatchForImport(String group, int length, int position) {
this.group = group;
matchLength = length;
matchPosition = position;
}
}
}