Package com.puppycrawl.tools.checkstyle.checks.imports

Class ImportOrderCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable
    public class ImportOrderCheck
extends AbstractCheck
    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 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 boolean. Default value is true.
    • Property 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. /regexp/). If an import matches two or more groups, the best match is selected (closest to the start, and the longest match). 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 java.lang.String[]. Default value is "".
    • Property option - Specify policy on the relative order between type imports and static imports. Type is com.puppycrawl.tools.checkstyle.checks.imports.ImportOrderOption. Default value is under.
    • Property ordered - Control whether type imports within each group should be sorted. It doesn't affect sorting for static imports. Type is boolean. Default value is true.
    • Property 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 boolean. Default value is false.
    • Property 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 option is set to top or bottom and when property staticGroups is enabled. Type is boolean. Default value is false.
    • Property sortStaticImportsAlphabetically - Control whether static imports located at top or bottom are sorted within the group. Type is boolean. Default value is false.
    • Property 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. /regexp/). If an import matches two or more groups, the best match is selected (closest to the start, and the longest match). 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 option is set to top or bottom. Type is java.lang.String[]. Default value is "".
    • Property useContainerOrderingForStatic - Control whether to use container ordering (Eclipse IDE term) for static imports or not. Type is boolean. Default value is false.

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • import.groups.separated.internally
    • import.ordering
    • import.separation
    Since:
    3.2

    • Field Detail

      • groups

        private String[] 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. /regexp/). If an import matches two or more groups, the best match is selected (closest to the start, and the longest match). 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.

      • staticGroups

        private String[] 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. /regexp/). If an import matches two or more groups, the best match is selected (closest to the start, and the longest match). 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 option is set to top or bottom.

      • separated

        private boolean 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.

      • separatedStaticGroups

        private boolean 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 option is set to top or bottom and when property staticGroups is enabled.

      • ordered

        private boolean ordered
        Control whether type imports within each group should be sorted. It doesn't affect sorting for static imports.

      • caseSensitive

        private boolean 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.

      • lastGroup

        private int lastGroup
        Last imported group.

      • lastImportLine

        private int lastImportLine
        Line number of last import.

      • beforeFirstImport

        private boolean beforeFirstImport
        Whether there were any imports.

      • staticImportsApart

        private boolean staticImportsApart
        Whether static and type import groups should be split apart. When the option property is set to INFLOW, ABOVE or UNDER, both the type and static imports use the properties groups and separated. When the option property is set to TOP or BOTTOM, static imports uses the properties staticGroups and separatedStaticGroups.

      • sortStaticImportsAlphabetically

        private boolean sortStaticImportsAlphabetically
        Control whether static imports located at top or bottom are sorted within the group.

      • useContainerOrderingForStatic

        private boolean useContainerOrderingForStatic
        Control whether to use container ordering (Eclipse IDE term) for static imports or not.

      • option

        private ImportOrderOption option
        Specify policy on the relative order between type imports and static imports.

      • groupsReg

        private Pattern[] groupsReg
        Complied array of patterns for property groups.

    • Method Detail

      • setOption

        public void setOption​(String optionStr)
        Setter to specify policy on the relative order between type imports and static imports.
        Parameters:
        optionStr - string to decode option from
        Throws:
        IllegalArgumentException - if unable to decode
        Since:
        5.0

      • setGroups

        public void setGroups​(String... packageGroups)
        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. /regexp/). If an import matches two or more groups, the best match is selected (closest to the start, and the longest match). 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.
        Parameters:
        packageGroups - a comma-separated list of package names/prefixes.
        Since:
        3.2

      • setStaticGroups

        public void setStaticGroups​(String... 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. /regexp/). If an import matches two or more groups, the best match is selected (closest to the start, and the longest match). 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 option is set to top or bottom.
        Parameters:
        packageGroups - a comma-separated list of package names/prefixes.
        Since:
        8.12

      • setOrdered

        public void setOrdered​(boolean ordered)
        Setter to control whether type imports within each group should be sorted. It doesn't affect sorting for static imports.
        Parameters:
        ordered - whether lexicographic ordering of imports within a group required or not.
        Since:
        3.2

      • setSeparated

        public void setSeparated​(boolean separated)
        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.
        Parameters:
        separated - whether groups should be separated by one blank line or comment.
        Since:
        3.2

      • setSeparatedStaticGroups

        public void setSeparatedStaticGroups​(boolean separatedStaticGroups)
        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 option is set to top or bottom and when property staticGroups is enabled.
        Parameters:
        separatedStaticGroups - whether groups should be separated by one blank line or comment.
        Since:
        8.12

      • setCaseSensitive

        public void setCaseSensitive​(boolean caseSensitive)
        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.
        Parameters:
        caseSensitive - whether string comparison should be case-sensitive.
        Since:
        3.3

      • setSortStaticImportsAlphabetically

        public void setSortStaticImportsAlphabetically​(boolean sortAlphabetically)
        Setter to control whether static imports located at top or bottom are sorted within the group.
        Parameters:
        sortAlphabetically - true or false.
        Since:
        6.5

      • setUseContainerOrderingForStatic

        public void setUseContainerOrderingForStatic​(boolean useContainerOrdering)
        Setter to control whether to use container ordering (Eclipse IDE term) for static imports or not.
        Parameters:
        useContainerOrdering - whether to use container ordering for static imports or not.
        Since:
        7.1

      • getAcceptableTokens

        public int[] getAcceptableTokens()
        Description copied from class: AbstractCheck
        The configurable token set. Used to protect Checks against malicious users who specify an unacceptable token set in the configuration file. The default implementation returns the check's default tokens.
        Specified by:
        getAcceptableTokens in class AbstractCheck
        Returns:
        the token set this check is designed for.
        See Also:
        TokenTypes

      • beginTree

        public void beginTree​(DetailAST rootAST)
        Description copied from class: AbstractCheck
        Called before the starting to process a tree. Ideal place to initialize information that is to be collected whilst processing a tree.
        Overrides:
        beginTree in class AbstractCheck
        Parameters:
        rootAST - the root of the tree

      • doVisitToken

        private void doVisitToken​(FullIdent ident,
                          boolean isStatic,
                          boolean previous,
                          DetailAST ast)
        Shares processing...
        Parameters:
        ident - the import to process.
        isStatic - whether the token is static or not.
        previous - previous non-static but current is static (above), or previous static but current is non-static (under).
        ast - node of the AST.

      • needSeparator

        private boolean needSeparator​(boolean isStatic)
        Checks whether import groups should be separated.
        Parameters:
        isStatic - whether the token is static or not.
        Returns:
        true if imports groups should be separated.

      • isSeparatorInGroup

        private boolean isSeparatorInGroup​(int groupIdx,
                                   boolean isStatic,
                                   int line)
        Checks whether imports group separated internally.
        Parameters:
        groupIdx - group number.
        isStatic - whether the token is static or not.
        line - the line of the current import.
        Returns:
        true if imports group are separated internally.

      • isSeparatorBeforeImport

        private boolean isSeparatorBeforeImport​(int line)
        Checks whether there is any separator before current import.
        Parameters:
        line - the line of the current import.
        Returns:
        true if there is separator before current import which isn't the first import.

      • doVisitTokenInSameGroup

        private void doVisitTokenInSameGroup​(boolean isStatic,
                                     boolean previous,
                                     String name,
                                     DetailAST ast)
        Shares processing...
        Parameters:
        isStatic - whether the token is static or not.
        previous - previous non-static but current is static (above), or previous static but current is non-static (under).
        name - the name of the current import.
        ast - node of the AST.

      • isWrongOrder

        private boolean isWrongOrder​(String name,
                             boolean isStatic)
        Checks whether import name is in wrong order.
        Parameters:
        name - import name.
        isStatic - whether it is a static import name.
        Returns:
        true if import name is in wrong order.

      • compareContainerOrder

        private static int compareContainerOrder​(String importName1,
                                         String importName2,
                                         boolean caseSensitive)
        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.

        Parameters:
        importName1 - first import name
        importName2 - second import name
        caseSensitive - whether the comparison of fully qualified import names is case-sensitive
        Returns:
        the value 0 if str1 is equal to str2; a value less than 0 if str is less than the str2 (container order or lexicographical); and a value greater than 0 if str1 is greater than str2 (container order or lexicographically)

      • getImportContainer

        private static String getImportContainer​(String qualifiedImportName)
        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
        Parameters:
        qualifiedImportName - fully qualified import name.
        Returns:
        import container name.

      • getGroupNumber

        private int getGroupNumber​(boolean isStatic,
                           String name)
        Finds out what group the specified import belongs to.
        Parameters:
        isStatic - whether the token is static or not.
        name - the import name to find.
        Returns:
        group number for given import name.

      • getGroupNumber

        private static int getGroupNumber​(Pattern[] patterns,
                                  String name)
        Finds out what group the specified import belongs to.
        Parameters:
        patterns - groups to check.
        name - the import name to find.
        Returns:
        group number for given import name.

      • compare

        private static int compare​(String string1,
                           String string2,
                           boolean caseSensitive)
        Compares two strings.
        Parameters:
        string1 - the first string
        string2 - the second string
        caseSensitive - whether the comparison is case-sensitive
        Returns:
        the value 0 if string1 is equal to string2; a value less than 0 if string1 is lexicographically less than the string2; and a value greater than 0 if string1 is lexicographically greater than string2

      • compilePatterns

        private static Pattern[] compilePatterns​(String... packageGroups)
        Compiles the list of package groups and the order they should occur in the file.
        Parameters:
        packageGroups - a comma-separated list of package names/prefixes.
        Returns:
        array of compiled patterns.
        Throws:
        IllegalArgumentException - if any of the package groups are not valid.