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Java趣味分享:try & finally

Java趣味分享:try & finally

考虑以下四个测试方法,它们会输出什么?

public class Test {

    public static void main(String/[/] args) {

        System.out.println(test1());

        System.out.println(test2());

        System.out.println(test3());

        System.out.println(test4());

    }

    private static int test1() {

        int i = 1;
        try {
            return i;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            i = 0;
        }

        return i;

    }

    private static int test2() {

        int i = 1;
        try {
            return i;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            i = 0;
            return i;
        }

    }

    private static User test3() {

        User user = new User("u1");
        try {
            return user;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            user = new User("u2");
        }

        return null;

    }

    private static User test4() {

        User user = new User("u1");
        try {
            return user;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            user.setName("u2");
        }

        return null;

    }

}

public class User {

    public User(String name) {
        this.name = name;
    }

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return name;
    }

}

答案如下:

1

0

u1

u2

结论

1、不管try,finally都会执行;

2、在try中return,在finally执行前会把结果保存起来,即使在finally中有修改也以try中保存的值为准,但如果是引用类型,修改的属性会以finally修改后的为准;

3、如果try/finally都有return,直接返回finally中的return。

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原文  https://www.maiyewang.com/archives/93687
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