Java如何主动从当前线程获取异常信息

// 主动获取当前线程异常栈信息
StackTraceElement[] stackTraceElements = Thread.currentThread().getStackTrace();

// 以日志的方式打出  \n  每一行错误栈信息结束后换行
log.error(StringUtils.join(stackTraceElements, '\n'));

Thread.UncaughtExceptionHandler exceptionHandler = (t, e) -> {
    System.out.println("报错线程:" + t.getName());
    System.out.println("线程抛出的异常:" + e);
};
Thread thread = new Thread(() -> {
    throw new RuntimeException("throw a new Exception ! ");
});
thread.setUncaughtExceptionHandler(exceptionHandler); // 设置异常处理器
thread.start();

Thread.UncaughtExceptionHandler exceptionHandler = (t, e) -> {
    System.out.println("报错线程:" + t.getName());
    System.out.println("线程抛出的异常:" + e);
};
Thread.setDefaultUncaughtExceptionHandler(exceptionHandler);

UncaughtExceptionHandler源码
// Thread.UncaughtExceptionHandler 
@FunctionalInterface
public interface UncaughtExceptionHandler {
    void uncaughtException(Thread t, Throwable e);
}

// 作用于当个Thread线程
private volatile UncaughtExceptionHandler uncaughtExceptionHandler;
// static修饰，其可以作用于所有Thread线程
private static volatile UncaughtExceptionHandler defaultUncaughtExceptionHandler;

public UncaughtExceptionHandler getUncaughtExceptionHandler() {
    return uncaughtExceptionHandler != null ?
        uncaughtExceptionHandler : group;
}

// Thread#getUncaughtExceptionHandler
public UncaughtExceptionHandler getUncaughtExceptionHandler() {
    return uncaughtExceptionHandler != null ?
        uncaughtExceptionHandler : group;
}

public class ThreadGroup implements Thread.UncaughtExceptionHandler {
    // ……
    public void uncaughtException(Thread t, Throwable e) {
        // 父级ThreadGroup的处理方法
        if (parent != null) {
            parent.uncaughtException(t, e);
        } else {
            // Thread 的全局默认处理方法
            Thread.UncaughtExceptionHandler ueh =
                Thread.getDefaultUncaughtExceptionHandler();
            if (ueh != null) {
                ueh.uncaughtException(t, e);
            } else if (!(e instanceof ThreadDeath)) {
                System.err.print("Exception in thread \""
                                 + t.getName() + "\" ");
                e.printStackTrace(System.err);
            }
        }
    }
    // ……
}

// ThreadPoolExecutor#afterExecute
class ExtendedExecutor extends ThreadPoolExecutor {
  protected void afterExecute(Runnable r, Throwable t) {
    super.afterExecute(r, t);
    // 如果Runnable是Future类型，那么异常将会直接通过Future返回
    if (t == null && r instanceof Future<?>) {
      try {
        Object result = ((Future<?>) r).get();
      } catch (CancellationException ce) {
          t = ce;
      } catch (ExecutionException ee) {
          t = ee.getCause();
      } catch (InterruptedException ie) {
          Thread.currentThread().interrupt(); // ignore/reset
      }
    }
    // 非Future类型
    if (t != null)
      System.out.println(t);
  }
}

// ThreadPoolExecutor#runWorker
final void runWorker(Worker w) {
    Thread wt = Thread.currentThread();
    Runnable task = w.firstTask; // 实际提交的任务
            // …………
            try {
                beforeExecute(wt, task); // task执行前的操作
                Throwable thrown = null; // 异常信息保存
                try {
                    task.run(); // 执行任务
                } catch (RuntimeException x) {
                    thrown = x; throw x;
                } catch (Error x) {
                    thrown = x; throw x;
                } catch (Throwable x) {
                    thrown = x; throw new Error(x);
                } finally {
                    afterExecute(task, thrown); // task执行后的操作，也就包括了异常的捕获工作
                }
            } finally {
                task = null;
                w.completedTasks++;
                w.unlock();
            }
        // ……
}

// ThreadPoolExecutor#afterExecute
protected void afterExecute(Runnable r, Throwable t) { }

// AbstractExecutorService#submit
public <T> Future<T> submit(Callable<T> task) {
    if (task == null) throw new NullPointerException();
    RunnableFuture<T> ftask = newTaskFor(task);
    execute(ftask);
    return ftask;
}

// Callable任务会被封装成FutureTask
protected <T> RunnableFuture<T> newTaskFor(Callable<T> callable) {
    return new FutureTask<T>(callable);
}

// FutureTask#run
public void run() {
    // ……
    try {
        Callable<V> c = callable;
        // ……
            // 这里将Callable的执行过程产生的异常都捕获了
            try {
                result = c.call();
                ran = true;
            } catch (Throwable ex) {
                result = null;
                ran = false;
                setException(ex);
            }
            if (ran)
                set(result);
        }
    } finally {
// ……