java - try-catch block java 9 中的 Stackwalker

Question

我正在尝试在异常 block 中打印堆栈遍历器，但它仅显示当前类

public class Test1 {
    public void test() throws Exception{
        Test2 test2 = new Test2();
        test2.test();
    }
}

public class Test2 {
    public void test() throws Exception{
        System.out.println(1/0);
    }
}

public class TestStackWalker {
      public static void main(String[] args) {
        Test1 test1 = new Test1();
        try {
            test1.test();
        } catch (Exception e) {
           StackWalker stack = StackWalker.getInstance();
           stack.forEach(System.out::println);
        }
    }
}

Answer 1

来自StackWalker文档:

The walk method opens a sequential stream of StackFrames for the current thread and then applies the given function to walk the StackFrame stream.

由于您是从主方法调用它 - 只分配了一个 StackFrame 并正在打印:

TestStackWalker.main(TestStackWalker.java:10)

如果您想访问异常堆栈跟踪的每个堆栈元素 - 使用 Throwable::getStackTrace它返回 StackTraceElement 数组:

class TestStackWalker {
    public static void main(String[] args) {
        Test1 test1 = new Test1();
        try {
            test1.test();
        } catch (Exception e) {
            Arrays.stream(e.getStackTrace()).forEach(System.out::println);
        }
    }
}

将打印:

Test2.test(Test2.java:3)
Test1.test(Test1.java:4)
TestStackWalker.main(TestStackWalker.java:7)

如果您只想打印 Throwable::printStackTrace应该足够了。