一 背景

一直以为Java静态块抛异常，没人捕获，虚拟机会推出，要不是最近debug到异常的执行流程，观念还正不了，自己看吧。

二 代码

（1）静态块抛异常类

/**
 * 静态块抛异常类
 */
public class App {

    static {
        System.out.println("static start !=============");
        if (true) {
            throw new RuntimeException("static test");
        }
        System.out.println("static finiah!=============");
    }

    public static void hello() {
        System.out.println("hello ! ");
    }
}

（2）调用类

/**
 * 调用静态块
 */
public class TestApp {
    public static void main(String[] args) {
        try {
            App.hello();
        } catch (Throwable e) {
            System.err.println("excepiton1 start : =========" );
            e.printStackTrace();
            System.err.println("excepiton1 finish! =========");
        }

        System.err.println("--------------------------------");
        try {
            App.hello();
        } catch (Throwable e) {
            System.err.println("excepiton2 start ! =========");
            e.printStackTrace();
            System.err.println("excepiton2 finish! =========");
        }
    }
}

三 执行结果

static start !=============
excepiton1 start : =========
java.lang.ExceptionInInitializerError
	at x.test.TestApp.main(TestApp.java:9)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: java.lang.RuntimeException: static test
	at x.test.App.<clinit>(App.java:11)
	... 6 more
excepiton1 finish! =========
--------------------------------
excepiton2 start ! =========
java.lang.NoClassDefFoundError: Could not initialize class x.test.App
	at x.test.TestApp.main(TestApp.java:18)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
excepiton2 finish! =========

四 说明

1）静态块在类首次使用时加载类后调用，如果调用过程产生异常，会抛到首次调用处，可以捕获。

2）后续调用该类，会出现找不到类异常