Recommendations for using objects between threads in Java

Question

I tried to search, but could not find the exact answer I was looking for, so I asked a new question.

If you want to share any mutable objects (objects) between multiple threads, are there any recommendations / principles / recommendations for this?

Or will it just change in each case?

Answer 1

Sharing mutable objects between threads is risky.

The safest way is to make objects immutable, you can freely share them.

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Answer 2

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Answer 4

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    public static void main(String[] args) throws InterruptedException {
        StringBuilder builder = new StringBuilder("");

        Thread one = new Thread() {
            public void run() {

                for (int i = 0; i < 1000; i++) {
                    //synchronized (builder) {
                        builder.append("thread one\n");
                    //}
                }
            }
        };
        Thread two = new Thread() {
            public void run() {

                for (int i = 0; i < 1000; i++) {
                    //synchronized (builder) {
                        builder.append("thread two\n");
                    //}
                }
            }
        };
        one.start();
        two.start();
        one.join();
        two.join();

        System.out.println(builder);
    }

Answer 5

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