Eclipse 为可访问代码提供死代码警告 [英] Eclipse gives dead code warning for reachable code

问题描述

以下代码会导致 Eclipse 显示死代码警告，尽管代码是可访问的.我在这里遗漏了什么，或者这是一个 Eclipse/javac 错误?

The following code causes Eclipse to display a dead code warning although the code is reachable. Am I missing something here, or is this an Eclipse/javac bug?

import java.util.ArrayList;

public class DeadCodeDemo {

    public static class SomeClosable implements AutoCloseable {
        @Override
        public void close() throws Exception {
        }
    }

    public static ArrayList<String> throwRuntime() {
        throw new RuntimeException();
    }

    public static void main(String[] args) {
        ArrayList<String> list = null;
        try {
            try (SomeClosable c = new SomeClosable()) {
                list = throwRuntime();
            }
            try (SomeClosable c = new SomeClosable()) {
                list.clear();
            }
        } catch (Exception e) {
            if (list != null) { // Warning: Redundant null check: The variable list cannot be null at this location
                System.out.println("List is not null");
            } else {
                System.out.println("List is null"); // Warning: Dead code
            }
        }
    }
}

代码打印List is null

我使用的是 Eclipse 4.7.3a (Oxygen.3a) 和 JDK 8_162

I'm using Eclipse 4.7.3a (Oxygen.3a) and JDK 8_162

推荐答案

我认为是 这个问题，仍然存在.

请记住，这是 Eclipse 警告，而不是 javac - 在该问题得到解决之前，这几乎是您应该关心的所有内容(即使它现在已有 7 年历史))

Just remember that this is Eclipse warning, not javac - and that is pretty much all you should care until that issue is resolved (even if it 7 years old now)

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