org.openrewrite.staticanalysis.NoFinalizer Maven / Gradle / Ivy

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/*
 * Copyright 2021 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 

 * https://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.openrewrite.staticanalysis;

import org.openrewrite.ExecutionContext;
import org.openrewrite.Recipe;
import org.openrewrite.TreeVisitor;
import org.openrewrite.internal.ListUtils;
import org.openrewrite.java.JavaIsoVisitor;
import org.openrewrite.java.MethodMatcher;
import org.openrewrite.java.tree.J;

import java.time.Duration;
import java.util.Collections;
import java.util.Set;

public class NoFinalizer extends Recipe {
    @Override
    public String getDisplayName() {
        return "Remove `finalize()` method";
    }

    @Override
    public String getDescription() {
        return "Finalizers are deprecated. Use of `finalize()` can lead to performance issues, deadlocks, hangs, and other undesirable behavior.";
    }

    @Override
    public Set getTags() {
        return Collections.singleton("RSPEC-S1111");
    }

    @Override
    public Duration getEstimatedEffortPerOccurrence() {
        return Duration.ofMinutes(20);
    }

    @Override
    public TreeVisitor getVisitor() {
        return new NoFinalizerVisitor();
    }

    private static class NoFinalizerVisitor extends JavaIsoVisitor {
        private static final MethodMatcher FINALIZER = new MethodMatcher("java.lang.Object finalize()", true);

        @Override
        public J.ClassDeclaration visitClassDeclaration(J.ClassDeclaration classDecl, ExecutionContext ctx) {
            J.ClassDeclaration cd = super.visitClassDeclaration(classDecl, ctx);
            cd = cd.withBody(cd.getBody().withStatements(ListUtils.map(cd.getBody().getStatements(), stmt -> {
                if (stmt instanceof J.MethodDeclaration) {
                    if (FINALIZER.matches((J.MethodDeclaration) stmt, classDecl)) {
                        return null;
                    }
                }
                return stmt;
            })));

            return cd;
        }

    }

}