JAVA主动抛异常的几种方式及捕捉结果输出对比

测试代码：

/**
     * 测试异常抛出及捕捉
     */
    @Test
    public void test() {
        try {
            this.testA();
        } catch (Exception ex) {
            System.out.println(CoreUtils.exceptionToString(ex));
        }
    }

    /**
     * 测试测试
     */
    private void testA() {
        try {
            String a = null;
            a.length();
        } catch (Exception ex) {
           //各种继续抛出异常的方式
        }
    }

1. throw ex

java.lang.NullPointerException
com.differ.jackyun.jackyunassservice.service.others.HgwTest.testA(HgwTest.java:)
com.differ.jackyun.jackyunassservice.service.others.HgwTest.test(HgwTest.java:)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:)
java.lang.reflect.Method.invoke(Method.java:)
org.junit.runners.model.FrameworkMethod$.runReflectiveCall(FrameworkMethod.java:)
org.junit.)
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:)
org.junit.)
org.junit.)
......

2. throw new RuntimeException(ex)

java.lang.RuntimeException: java.lang.NullPointerException
com.differ.jackyun.jackyunassservice.service.others.HgwTest.testA(HgwTest.java:)
com.differ.jackyun.jackyunassservice.service.others.HgwTest.test(HgwTest.java:)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:)
java.lang.reflect.Method.invoke(Method.java:)
org.junit.runners.model.FrameworkMethod$.runReflectiveCall(FrameworkMethod.java:)
org.junit.)
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:)
org.junit.)
org.junit.)
......

3. throw new RuntimeException("执行某个功能发生异常", ex)

java.lang.RuntimeException: 执行某个功能发生异常
com.differ.jackyun.jackyunassservice.service.others.HgwTest.testA(HgwTest.java:)
com.differ.jackyun.jackyunassservice.service.others.HgwTest.test(HgwTest.java:)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:)
java.lang.reflect.Method.invoke(Method.java:)
org.junit.runners.model.FrameworkMethod$.runReflectiveCall(FrameworkMethod.java:)
org.junit.)
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:)
org.junit.)
org.junit.)
......

4. throw new RuntimeException("执行某个功能发生异常：" + CoreUtils.exceptionToString(ex))

java.lang.RuntimeException: 执行某个功能发生异常：java.lang.NullPointerException
com.differ.jackyun.jackyunassservice.service.others.HgwTest.testA(HgwTest.java:)
com.differ.jackyun.jackyunassservice.service.others.HgwTest.test(HgwTest.java:)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:)
java.lang.reflect.Method.invoke(Method.java:)
org.junit.runners.model.FrameworkMethod$.runReflectiveCall(FrameworkMethod.java:)
org.junit.)
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:)
org.junit.)
org.junit.)
......

总结：第3种方式抛出的异常（即：throw new RuntimeException("执行某个功能发生异常", ex)），会丢失关键的异常原因，故开发时慎用！！！