AutoCloseable使用与注意，try-with-resources（推荐）

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• 使用try-with-resources（推荐），不要使用try-finally。
• 实现AutoCloseable接口，并实现close方法。
• 使用try-with-resources可以捕获close中的异常，通过throwable的getSuppressed
• 在退出try-with-resources块的时候会自动调用close方法。下面是AutoCloseable的文档说明
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package org.ziegler.javabase.autoClaseable;

public class CloseableObjectA implements AutoCloseable {
    public CloseableObjectA() {
        System.out.println("CloseableObjectA");
    }

    @Override
    public void close() {
        System.out.println("CloseableObjectA.close");

        throw new RuntimeException("CloseableObjectA.close throw exception");
    }

    public void testException() {
        throw new RuntimeException("throwException test");
    }
}

package org.ziegler.javabase.autoClaseable;

public class CloseableObjectB implements AutoCloseable {
    public CloseableObjectB() {
        System.out.println("CloseableObjectB");
    }

    @Override
    public void close() {
        System.out.println("CloseableObjectB.close");
        throw new RuntimeException("CloseableObjectB.close throw exception");
    }
}

package org.ziegler.javabase.autoClaseable;

import org.junit.jupiter.api.Test;

public class CloseableTest {

    @Test
    void test() {

        try (CloseableObjectA closeableObjectA = new CloseableObjectA();
             CloseableObjectB closeableObjectB = new CloseableObjectB()) {

            System.out.println("closeableObjectA.toString() = " + closeableObjectA.toString());
            System.out.println("closeableObjectB.toString() = " + closeableObjectB.toString());

            closeableObjectA.testException();
        } catch (Throwable throwable) {
            System.out.println("throwable:" + throwable.getMessage());
            for (Throwable st : throwable.getSuppressed()) {
                System.out.println("suppressed:" + st.getMessage());
            }
        } finally {
            System.out.println("try-with-resources finally");
        }
    }
}