com.puppycrawl.tools.checkstyle.checks.imports.ImportOrderCheck Maven / Gradle / Ivy
///////////////////////////////////////////////////////////////////////////////////////////////
// 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.Locale;
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;
import com.puppycrawl.tools.checkstyle.utils.UnmodifiableCollectionUtil;
/**
*
* Checks the ordering/grouping of imports. Features are:
*
*
* -
* groups type/static imports: ensures that groups of imports come in a specific order
* (e.g., java. comes first, javax. comes second, then everything else)
*
* -
* adds a separation between type import groups : ensures that a blank line sit between each group
*
* -
* type/static import groups aren't separated internally: ensures that each group aren't separated
* internally by blank line or comment
*
* -
* sorts type/static imports inside each group: ensures that imports within each group are in
* lexicographic order
*
* -
* sorts according to case: ensures that the comparison between imports is case-sensitive, in
* ASCII sort order
*
* -
* arrange static imports: ensures the relative order between type imports and static imports
* (see
* ImportOrderOption)
*
*
*
* -
* Property {@code caseSensitive} - Control whether string comparison should be
* case-sensitive or not. Case-sensitive sorting is in
* ASCII sort order.
* It affects both type imports and static imports.
* Type is {@code boolean}.
* Default value is {@code true}.
*
* -
* Property {@code groups} - Specify list of type import groups. Every group identified
* either by a common prefix string, or by a regular expression enclosed in forward slashes
* (e.g. {@code /regexp/}). All type imports, which does not match any group, falls into an
* additional group, located at the end.
* Thus, the empty list of type groups (the default value) means one group for all type imports.
* Type is {@code java.lang.String[]}.
* Default value is {@code ""}.
*
* -
* Property {@code option} - Specify policy on the relative order between type imports and static
* imports.
* Type is {@code com.puppycrawl.tools.checkstyle.checks.imports.ImportOrderOption}.
* Default value is {@code under}.
*
* -
* Property {@code ordered} - Control whether type imports within each group should be
* sorted.
* It doesn't affect sorting for static imports.
* Type is {@code boolean}.
* Default value is {@code true}.
*
* -
* Property {@code separated} - Control whether type import groups should be separated
* by, at least, one blank line or comment and aren't separated internally.
* It doesn't affect separations for static imports.
* Type is {@code boolean}.
* Default value is {@code false}.
*
* -
* Property {@code separatedStaticGroups} - Control whether static import groups should
* be separated by, at least, one blank line or comment and aren't separated internally.
* This property has effect only when the property {@code option} is set to {@code top}
* or {@code bottom} and when property {@code staticGroups} is enabled.
* Type is {@code boolean}.
* Default value is {@code false}.
*
* -
* Property {@code sortStaticImportsAlphabetically} - Control whether
* static imports located at top or bottom are sorted within the group.
* Type is {@code boolean}.
* Default value is {@code false}.
*
* -
* Property {@code staticGroups} - Specify list of static import groups. Every group
* identified either by a common prefix string, or by a regular expression enclosed in forward
* slashes (e.g. {@code /regexp/}). All static imports, which does not match any group, fall into
* an additional group, located at the end. Thus, the empty list of static groups (the default
* value) means one group for all static imports. This property has effect only when the property
* {@code option} is set to {@code top} or {@code bottom}.
* Type is {@code java.lang.String[]}.
* Default value is {@code ""}.
*
* -
* Property {@code useContainerOrderingForStatic} - Control whether to use container
* ordering (Eclipse IDE term) for static imports or not.
* Type is {@code boolean}.
* Default value is {@code false}.
*
*
*
* Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
*
*
* Violation Message Keys:
*
*
* -
* {@code import.groups.separated.internally}
*
* -
* {@code import.ordering}
*
* -
* {@code import.separation}
*
*
*
* @since 3.2
*/
@FileStatefulCheck
public class ImportOrderCheck
extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_SEPARATION = "import.separation";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_ORDERING = "import.ordering";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_SEPARATED_IN_GROUP = "import.groups.separated.internally";
/** The special wildcard that catches all remaining groups. */
private static final String WILDCARD_GROUP_NAME = "*";
/** The Forward slash. */
private static final String FORWARD_SLASH = "/";
/** Empty array of pattern type needed to initialize check. */
private static final Pattern[] EMPTY_PATTERN_ARRAY = new Pattern[0];
/**
* Specify list of type import groups. Every group identified either by a common prefix
* string, or by a regular expression enclosed in forward slashes (e.g. {@code /regexp/}).
* All type imports, which does not match any group, falls into an additional group,
* located at the end. Thus, the empty list of type groups (the default value) means one group
* for all type imports.
*/
private String[] groups = CommonUtil.EMPTY_STRING_ARRAY;
/**
* Specify list of static import groups. Every group identified either by a common prefix
* string, or by a regular expression enclosed in forward slashes (e.g. {@code /regexp/}).
* All static imports, which does not match any group, fall into an additional group, located
* at the end. Thus, the empty list of static groups (the default value) means one group for all
* static imports. This property has effect only when the property {@code option} is set to
* {@code top} or {@code bottom}.
*/
private String[] staticGroups = CommonUtil.EMPTY_STRING_ARRAY;
/**
* Control whether type import groups should be separated by, at least, one blank
* line or comment and aren't separated internally. It doesn't affect separations for static
* imports.
*/
private boolean separated;
/**
* Control whether static import groups should be separated by, at least, one blank
* line or comment and aren't separated internally. This property has effect only when the
* property {@code option} is set to {@code top} or {@code bottom} and when property
* {@code staticGroups} is enabled.
*/
private boolean separatedStaticGroups;
/**
* Control whether type imports within each group should be sorted.
* It doesn't affect sorting for static imports.
*/
private boolean ordered = true;
/**
* Control whether string comparison should be case-sensitive or not. Case-sensitive
* sorting is in ASCII sort order.
* It affects both type imports and static imports.
*/
private boolean caseSensitive = true;
/** Last imported group. */
private int lastGroup;
/** Line number of last import. */
private int lastImportLine;
/** Name of last import. */
private String lastImport;
/** If last import was static. */
private boolean lastImportStatic;
/** Whether there were any imports. */
private boolean beforeFirstImport;
/**
* Whether static and type import groups should be split apart.
* When the {@code option} property is set to {@code INFLOW}, {@code ABOVE} or {@code UNDER},
* both the type and static imports use the properties {@code groups} and {@code separated}.
* When the {@code option} property is set to {@code TOP} or {@code BOTTOM}, static imports
* uses the properties {@code staticGroups} and {@code separatedStaticGroups}.
**/
private boolean staticImportsApart;
/**
* Control whether static imports located at top or bottom are
* sorted within the group.
*/
private boolean sortStaticImportsAlphabetically;
/**
* Control whether to use container ordering (Eclipse IDE term) for static imports
* or not.
*/
private boolean useContainerOrderingForStatic;
/**
* Specify policy on the relative order between type imports and static imports.
*/
private ImportOrderOption option = ImportOrderOption.UNDER;
/**
* Complied array of patterns for property {@code groups}.
*/
private Pattern[] groupsReg = EMPTY_PATTERN_ARRAY;
/**
* Complied array of patterns for property {@code staticGroups}.
*/
private Pattern[] staticGroupsReg = EMPTY_PATTERN_ARRAY;
/**
* Setter to specify policy on the relative order between type imports and static imports.
*
* @param optionStr string to decode option from
* @throws IllegalArgumentException if unable to decode
* @since 5.0
*/
public void setOption(String optionStr) {
option = ImportOrderOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
}
/**
* Setter to specify list of type import groups. Every group identified either by a
* common prefix string, or by a regular expression enclosed in forward slashes
* (e.g. {@code /regexp/}). All type imports, which does not match any group, falls into an
* additional group, located at the end. Thus, the empty list of type groups (the default value)
* means one group for all type imports.
*
* @param packageGroups a comma-separated list of package names/prefixes.
* @since 3.2
*/
public void setGroups(String... packageGroups) {
groups = UnmodifiableCollectionUtil.copyOfArray(packageGroups, packageGroups.length);
groupsReg = compilePatterns(packageGroups);
}
/**
* Setter to specify list of static import groups. Every group identified either by a
* common prefix string, or by a regular expression enclosed in forward slashes
* (e.g. {@code /regexp/}). All static imports, which does not match any group, fall into an
* additional group, located at the end. Thus, the empty list of static groups (the default
* value) means one group for all static imports. This property has effect only when
* the property {@code option} is set to {@code top} or {@code bottom}.
*
* @param packageGroups a comma-separated list of package names/prefixes.
* @since 8.12
*/
public void setStaticGroups(String... packageGroups) {
staticGroups = UnmodifiableCollectionUtil.copyOfArray(packageGroups, packageGroups.length);
staticGroupsReg = compilePatterns(packageGroups);
}
/**
* Setter to control whether type imports within each group should be sorted.
* It doesn't affect sorting for static imports.
*
* @param ordered
* whether lexicographic ordering of imports within a group
* required or not.
* @since 3.2
*/
public void setOrdered(boolean ordered) {
this.ordered = ordered;
}
/**
* Setter to control whether type import groups should be separated by, at least,
* one blank line or comment and aren't separated internally.
* It doesn't affect separations for static imports.
*
* @param separated
* whether groups should be separated by one blank line or comment.
* @since 3.2
*/
public void setSeparated(boolean separated) {
this.separated = separated;
}
/**
* Setter to control whether static import groups should be separated by, at least,
* one blank line or comment and aren't separated internally.
* This property has effect only when the property
* {@code option} is set to {@code top} or {@code bottom} and when property {@code staticGroups}
* is enabled.
*
* @param separatedStaticGroups
* whether groups should be separated by one blank line or comment.
* @since 8.12
*/
public void setSeparatedStaticGroups(boolean separatedStaticGroups) {
this.separatedStaticGroups = separatedStaticGroups;
}
/**
* Setter to control whether string comparison should be case-sensitive or not.
* Case-sensitive sorting is in
* ASCII sort order.
* It affects both type imports and static imports.
*
* @param caseSensitive
* whether string comparison should be case-sensitive.
* @since 3.3
*/
public void setCaseSensitive(boolean caseSensitive) {
this.caseSensitive = caseSensitive;
}
/**
* Setter to control whether static imports located at top or
* bottom are sorted within the group.
*
* @param sortAlphabetically true or false.
* @since 6.5
*/
public void setSortStaticImportsAlphabetically(boolean sortAlphabetically) {
sortStaticImportsAlphabetically = sortAlphabetically;
}
/**
* Setter to control whether to use container ordering (Eclipse IDE term) for static
* imports or not.
*
* @param useContainerOrdering whether to use container ordering for static imports or not.
* @since 7.1
*/
public void setUseContainerOrderingForStatic(boolean useContainerOrdering) {
useContainerOrderingForStatic = useContainerOrdering;
}
@Override
public int[] getDefaultTokens() {
return getRequiredTokens();
}
@Override
public int[] getAcceptableTokens() {
return getRequiredTokens();
}
@Override
public int[] getRequiredTokens() {
return new int[] {TokenTypes.IMPORT, TokenTypes.STATIC_IMPORT};
}
@Override
public void beginTree(DetailAST rootAST) {
lastGroup = Integer.MIN_VALUE;
lastImportLine = Integer.MIN_VALUE;
lastImportStatic = false;
beforeFirstImport = true;
staticImportsApart =
option == ImportOrderOption.TOP || option == ImportOrderOption.BOTTOM;
}
// -@cs[CyclomaticComplexity] SWITCH was transformed into IF-ELSE.
@Override
public void visitToken(DetailAST ast) {
final FullIdent ident;
final boolean isStatic;
if (ast.getType() == TokenTypes.IMPORT) {
ident = FullIdent.createFullIdentBelow(ast);
isStatic = false;
}
else {
ident = FullIdent.createFullIdent(ast.getFirstChild()
.getNextSibling());
isStatic = true;
}
// using set of IF instead of SWITCH to analyze Enum options to satisfy coverage.
// https://github.com/checkstyle/checkstyle/issues/1387
if (option == ImportOrderOption.TOP || option == ImportOrderOption.ABOVE) {
final boolean isStaticAndNotLastImport = isStatic && !lastImportStatic;
doVisitToken(ident, isStatic, isStaticAndNotLastImport, ast);
}
else if (option == ImportOrderOption.BOTTOM || option == ImportOrderOption.UNDER) {
final boolean isLastImportAndNonStatic = lastImportStatic && !isStatic;
doVisitToken(ident, isStatic, isLastImportAndNonStatic, ast);
}
else if (option == ImportOrderOption.INFLOW) {
// "previous" argument is useless here
doVisitToken(ident, isStatic, true, ast);
}
else {
throw new IllegalStateException(
"Unexpected option for static imports: " + option);
}
lastImportLine = ast.findFirstToken(TokenTypes.SEMI).getLineNo();
lastImportStatic = isStatic;
beforeFirstImport = false;
}
/**
* Shares processing...
*
* @param ident the import to process.
* @param isStatic whether the token is static or not.
* @param previous previous non-static but current is static (above), or
* previous static but current is non-static (under).
* @param ast node of the AST.
*/
private void doVisitToken(FullIdent ident, boolean isStatic, boolean previous, DetailAST ast) {
final String name = ident.getText();
final int groupIdx = getGroupNumber(isStatic && staticImportsApart, name);
if (groupIdx > lastGroup) {
if (!beforeFirstImport
&& ast.getLineNo() - lastImportLine < 2
&& needSeparator(isStatic)) {
log(ast, MSG_SEPARATION, name);
}
}
else if (groupIdx == lastGroup) {
doVisitTokenInSameGroup(isStatic, previous, name, ast);
}
else {
log(ast, MSG_ORDERING, name);
}
if (isSeparatorInGroup(groupIdx, isStatic, ast.getLineNo())) {
log(ast, MSG_SEPARATED_IN_GROUP, name);
}
lastGroup = groupIdx;
lastImport = name;
}
/**
* Checks whether import groups should be separated.
*
* @param isStatic whether the token is static or not.
* @return true if imports groups should be separated.
*/
private boolean needSeparator(boolean isStatic) {
final boolean typeImportSeparator = !isStatic && separated;
final boolean staticImportSeparator;
if (staticImportsApart) {
staticImportSeparator = isStatic && separatedStaticGroups;
}
else {
staticImportSeparator = separated;
}
final boolean separatorBetween = isStatic != lastImportStatic
&& (separated || separatedStaticGroups);
return typeImportSeparator || staticImportSeparator || separatorBetween;
}
/**
* Checks whether imports group separated internally.
*
* @param groupIdx group number.
* @param isStatic whether the token is static or not.
* @param line the line of the current import.
* @return true if imports group are separated internally.
*/
private boolean isSeparatorInGroup(int groupIdx, boolean isStatic, int line) {
final boolean inSameGroup = groupIdx == lastGroup;
return (inSameGroup || !needSeparator(isStatic)) && isSeparatorBeforeImport(line);
}
/**
* Checks whether there is any separator before current import.
*
* @param line the line of the current import.
* @return true if there is separator before current import which isn't the first import.
*/
private boolean isSeparatorBeforeImport(int line) {
return line - lastImportLine > 1;
}
/**
* Shares processing...
*
* @param isStatic whether the token is static or not.
* @param previous previous non-static but current is static (above), or
* previous static but current is non-static (under).
* @param name the name of the current import.
* @param ast node of the AST.
*/
private void doVisitTokenInSameGroup(boolean isStatic,
boolean previous, String name, DetailAST ast) {
if (ordered) {
if (option == ImportOrderOption.INFLOW) {
if (isWrongOrder(name, isStatic)) {
log(ast, MSG_ORDERING, name);
}
}
else {
final boolean shouldFireError =
// previous non-static but current is static (above)
// or
// previous static but current is non-static (under)
previous
||
// current and previous static or current and
// previous non-static
lastImportStatic == isStatic
&& isWrongOrder(name, isStatic);
if (shouldFireError) {
log(ast, MSG_ORDERING, name);
}
}
}
}
/**
* Checks whether import name is in wrong order.
*
* @param name import name.
* @param isStatic whether it is a static import name.
* @return true if import name is in wrong order.
*/
private boolean isWrongOrder(String name, boolean isStatic) {
final boolean result;
if (isStatic) {
if (useContainerOrderingForStatic) {
result = compareContainerOrder(lastImport, name, caseSensitive) > 0;
}
else if (staticImportsApart) {
result = sortStaticImportsAlphabetically
&& compare(lastImport, name, caseSensitive) > 0;
}
else {
result = compare(lastImport, name, caseSensitive) > 0;
}
}
else {
// out of lexicographic order
result = compare(lastImport, name, caseSensitive) > 0;
}
return result;
}
/**
* Compares two import strings.
* We first compare the container of the static import, container being the type enclosing
* the static element being imported. When this returns 0, we compare the qualified
* import name. For e.g. this is what is considered to be container names:
*
* import static HttpConstants.COLON => HttpConstants
* import static HttpHeaders.addHeader => HttpHeaders
* import static HttpHeaders.setHeader => HttpHeaders
* import static HttpHeaders.Names.DATE => HttpHeaders.Names
*
*
* According to this logic, HttpHeaders.Names would come after HttpHeaders.
* For more details, see
* static imports comparison method in Eclipse.
*
*
* @param importName1 first import name
* @param importName2 second import name
* @param caseSensitive whether the comparison of fully qualified import names is
* case-sensitive
* @return the value {@code 0} if str1 is equal to str2; a value
* less than {@code 0} if str is less than the str2 (container order
* or lexicographical); and a value greater than {@code 0} if str1 is greater than str2
* (container order or lexicographically)
*/
private static int compareContainerOrder(String importName1, String importName2,
boolean caseSensitive) {
final String container1 = getImportContainer(importName1);
final String container2 = getImportContainer(importName2);
final int compareContainersOrderResult;
if (caseSensitive) {
compareContainersOrderResult = container1.compareTo(container2);
}
else {
compareContainersOrderResult = container1.compareToIgnoreCase(container2);
}
final int result;
if (compareContainersOrderResult == 0) {
result = compare(importName1, importName2, caseSensitive);
}
else {
result = compareContainersOrderResult;
}
return result;
}
/**
* Extracts import container name from fully qualified import name.
* An import container name is the type which encloses the static element being imported.
* For example, HttpConstants, HttpHeaders, HttpHeaders.Names are import container names:
*
* import static HttpConstants.COLON => HttpConstants
* import static HttpHeaders.addHeader => HttpHeaders
* import static HttpHeaders.setHeader => HttpHeaders
* import static HttpHeaders.Names.DATE => HttpHeaders.Names
*
*
* @param qualifiedImportName fully qualified import name.
* @return import container name.
*/
private static String getImportContainer(String qualifiedImportName) {
final int lastDotIndex = qualifiedImportName.lastIndexOf('.');
return qualifiedImportName.substring(0, lastDotIndex);
}
/**
* Finds out what group the specified import belongs to.
*
* @param isStatic whether the token is static or not.
* @param name the import name to find.
* @return group number for given import name.
*/
private int getGroupNumber(boolean isStatic, String name) {
final Pattern[] patterns;
if (isStatic) {
patterns = staticGroupsReg;
}
else {
patterns = groupsReg;
}
int number = getGroupNumber(patterns, name);
if (isStatic && option == ImportOrderOption.BOTTOM) {
number += groups.length + 1;
}
else if (!isStatic && option == ImportOrderOption.TOP) {
number += staticGroups.length + 1;
}
return number;
}
/**
* Finds out what group the specified import belongs to.
*
* @param patterns groups to check.
* @param name the import name to find.
* @return group number for given import name.
*/
private static int getGroupNumber(Pattern[] patterns, String name) {
int bestIndex = patterns.length;
int bestEnd = -1;
int bestPos = Integer.MAX_VALUE;
// find out what group this belongs in
// loop over patterns and get index
for (int i = 0; i < patterns.length; i++) {
final Matcher matcher = patterns[i].matcher(name);
if (matcher.find()) {
if (matcher.start() < bestPos) {
bestIndex = i;
bestEnd = matcher.end();
bestPos = matcher.start();
}
else if (matcher.start() == bestPos && matcher.end() > bestEnd) {
bestIndex = i;
bestEnd = matcher.end();
}
}
}
return bestIndex;
}
/**
* Compares two strings.
*
* @param string1
* the first string
* @param string2
* the second string
* @param caseSensitive
* whether the comparison is case-sensitive
* @return the value {@code 0} if string1 is equal to string2; a value
* less than {@code 0} if string1 is lexicographically less
* than the string2; and a value greater than {@code 0} if
* string1 is lexicographically greater than string2
*/
private static int compare(String string1, String string2,
boolean caseSensitive) {
final int result;
if (caseSensitive) {
result = string1.compareTo(string2);
}
else {
result = string1.compareToIgnoreCase(string2);
}
return result;
}
/**
* Compiles the list of package groups and the order they should occur in the file.
*
* @param packageGroups a comma-separated list of package names/prefixes.
* @return array of compiled patterns.
* @throws IllegalArgumentException if any of the package groups are not valid.
*/
private static Pattern[] compilePatterns(String... packageGroups) {
final Pattern[] patterns = new Pattern[packageGroups.length];
for (int i = 0; i < packageGroups.length; i++) {
String pkg = packageGroups[i];
final Pattern grp;
// if the pkg name is the wildcard, make it match zero chars
// from any name, so it will always be used as last resort.
if (WILDCARD_GROUP_NAME.equals(pkg)) {
// matches any package
grp = Pattern.compile("");
}
else if (pkg.startsWith(FORWARD_SLASH)) {
if (!pkg.endsWith(FORWARD_SLASH)) {
throw new IllegalArgumentException("Invalid group: " + pkg);
}
pkg = pkg.substring(1, pkg.length() - 1);
grp = Pattern.compile(pkg);
}
else {
final StringBuilder pkgBuilder = new StringBuilder(pkg);
if (!pkg.endsWith(".")) {
pkgBuilder.append('.');
}
grp = Pattern.compile("^" + Pattern.quote(pkgBuilder.toString()));
}
patterns[i] = grp;
}
return patterns;
}
}
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