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Use explicit this.field and this.method()

Recipe IDorg.openrewrite.staticanalysis.ExplicitThis
Artifactorg.openrewrite.recipe:rewrite-static-analysis

Add explicit 'this.' prefix to field and method access.

Single recipeOpenRewriteModerne Source Available License
Try in PlatformTry this recipe in the Moderne platform. Not a user yet? You’ll get a no-setup demo environment, with nothing to install or configure.

Examples​

java
Before
import java.util.function.Consumer;

class Parent {
    private String parentField;

    Parent(String value) {
        parentField = value;
    }
}

class Test extends Parent {
    private String value;
    private String field;
    private String field1;
    private String field2;
    private static String staticField;
    private String alreadyPrefixed;

    private String fieldInit1 = "initial";
    private String fieldInit2 = field1;
    private String fieldInit3 = field1 + field2;

    private static String staticFieldInit = staticField;

    static {
        staticField = "static initializer";
        staticHelper();
    }

    {
        field = "instance initializer";
        field1 = field2;
    }

    Test(String value) {
        super(value);
        // Shadowed parameter: looks like a bug but replacing would change semantics
        value = value;
        field = "constructor";
        field1 = field2;
    }

    Test() {
        this("default");
    }

    void instanceMethod(String parameter) {
        field = "value";
        field1 = field2;
        helper();
        staticField = "static context";
        staticMethod();

        String localVariable = parameter;
        String result = parameter + localVariable;

        this.alreadyPrefixed = "already has this";
        this.alreadyPrefixedMethod();
        super.toString();

        Consumer<String> lambda = s -> {
            field = s;
            field1 = field2;
        };

        Runnable runnable = () -> field = "lambda";
    }

    static void staticMethod() {
        staticField = "static context";
        staticHelper();
    }

    // Shadowed parameter: looks like a bug but replacing would change semantics
    void setField(String field) {
        field = field;
    }

    void helper() {}
    void alreadyPrefixedMethod() {}
    static void staticHelper() {}

    class Inner {
        private String innerField;

        void method() {
            innerField = "inner";
            field = "outer";
            Consumer<String> lambda = s -> {
                innerField = s;
                field = s;
            };
        }

        class Nested {
            private String nestedField;

            void method() {
                nestedField = "nested";
                innerField = "inner";
                field = "outer";
            }
        }
    }

    static class StaticNested {
        private String nestedField;
        private static String nestedStaticField;

        void method() {
            nestedField = "nested";
            nestedStaticField = "static";
            staticField = "outer static";
        }

        static void staticMethod() {
            nestedStaticField = "static";
            staticField = "outer static";
        }
    }

    void anonymousClassExample() {
        Runnable r = new Runnable() {
            private String anonymousField = "anonymous";

            @Override
            public void run() {
                field = "outer";
                String local = anonymousField;
            }
        };
    }
}
After
import java.util.function.Consumer;

class Parent {
    private String parentField;

    Parent(String value) {
        this.parentField = value;
    }
}

class Test extends Parent {
    private String value;
    private String field;
    private String field1;
    private String field2;
    private static String staticField;
    private String alreadyPrefixed;

    private String fieldInit1 = "initial";
    private String fieldInit2 = this.field1;
    private String fieldInit3 = this.field1 + this.field2;

    private static String staticFieldInit = staticField;

    static {
        staticField = "static initializer";
        staticHelper();
    }

    {
        this.field = "instance initializer";
        this.field1 = this.field2;
    }

    Test(String value) {
        super(value);
        // Shadowed parameter: looks like a bug but replacing would change semantics
        value = value;
        this.field = "constructor";
        this.field1 = this.field2;
    }

    Test() {
        this("default");
    }

    void instanceMethod(String parameter) {
        this.field = "value";
        this.field1 = this.field2;
        this.helper();
        staticField = "static context";
        staticMethod();

        String localVariable = parameter;
        String result = parameter + localVariable;

        this.alreadyPrefixed = "already has this";
        this.alreadyPrefixedMethod();
        super.toString();

        Consumer<String> lambda = s -> {
            this.field = s;
            this.field1 = this.field2;
        };

        Runnable runnable = () -> this.field = "lambda";
    }

    static void staticMethod() {
        staticField = "static context";
        staticHelper();
    }

    // Shadowed parameter: looks like a bug but replacing would change semantics
    void setField(String field) {
        field = field;
    }

    void helper() {}
    void alreadyPrefixedMethod() {}
    static void staticHelper() {}

    class Inner {
        private String innerField;

        void method() {
            this.innerField = "inner";
            Test.this.field = "outer";
            Consumer<String> lambda = s -> {
                this.innerField = s;
                Test.this.field = s;
            };
        }

        class Nested {
            private String nestedField;

            void method() {
                this.nestedField = "nested";
                Inner.this.innerField = "inner";
                Test.this.field = "outer";
            }
        }
    }

    static class StaticNested {
        private String nestedField;
        private static String nestedStaticField;

        void method() {
            this.nestedField = "nested";
            nestedStaticField = "static";
            staticField = "outer static";
        }

        static void staticMethod() {
            nestedStaticField = "static";
            staticField = "outer static";
        }
    }

    void anonymousClassExample() {
        Runnable r = new Runnable() {
            private String anonymousField = "anonymous";

            @Override
            public void run() {
                Test.this.field = "outer";
                String local = this.anonymousField;
            }
        };
    }
}

Usage​

Run this recipe

This recipe has no required configuration options. Users of Moderne can run it via the Moderne CLI.

You will need to have configured the Moderne CLI on your machine before you can run the following command.

shell
mod run . --recipe ExplicitThis

If the recipe is not available locally, then you can install it using:

mod config recipes jar install org.openrewrite.recipe:rewrite-static-analysis:2.38.0

Data tables​

Source files that had results
org.openrewrite.table.SourcesFileResults

Source files that were modified by the recipe run.

ColumnDescription
Source path before the runThe source path of the file before the run. null when a source file was created during the run.
Source path after the runA recipe may modify the source path. This is the path after the run. null when a source file was deleted during the run.
Parent of the recipe that made changesIn a hierarchical recipe, the parent of the recipe that made a change. Empty if this is the root of a hierarchy or if the recipe is not hierarchical at all.
Recipe that made changesThe specific recipe that made a change.
Estimated time savingAn estimated effort that a developer to fix manually instead of using this recipe, in unit of seconds.
CycleThe recipe cycle in which the change was made.
Source files that had search results
org.openrewrite.table.SearchResults

Search results that were found during the recipe run.

ColumnDescription
Source path of search result before the runThe source path of the file with the search result markers present.
Source path of search result after run the runA recipe may modify the source path. This is the path after the run. null when a source file was deleted during the run.
ResultThe trimmed printed tree of the LST element that the marker is attached to.
DescriptionThe content of the description of the marker.
Recipe that added the search markerThe specific recipe that added the Search marker.
Source files that errored on a recipe
org.openrewrite.table.SourcesFileErrors

The details of all errors produced by a recipe run.

ColumnDescription
Source pathThe file that failed to parse.
Recipe that made changesThe specific recipe that made a change.
Stack traceThe stack trace of the failure.
Recipe performance
org.openrewrite.table.RecipeRunStats

Statistics used in analyzing the performance of recipes.

ColumnDescription
The recipeThe recipe whose stats are being measured both individually and cumulatively.
Source file countThe number of source files the recipe ran over.
Source file changed countThe number of source files which were changed in the recipe run. Includes files created, deleted, and edited.
Cumulative scanning time (ns)The total time spent across the scanning phase of this recipe.
Max scanning time (ns)The max time scanning any one source file.
Cumulative edit time (ns)The total time spent across the editing phase of this recipe.
Max edit time (ns)The max time editing any one source file.