try-catch-finally和throw、throws調用順序

題目1.ReturnExceptionDemo

package com.atguigu.java2;

public class ReturnExceptionDemo {
	static void methodA() {
		try {
			System.out.println("進入方法A");
			throw new RuntimeException("製造異常");
		} finally {
			System.out.println("用A方法的finally");
		}
	}

	static void methodB() {
		try {
			System.out.println("進入方法B");
			return;
		} finally {
			System.out.println("調用B方法的finally");
		}
	}

	public static void main(String[] args) {
		try {
			methodA();
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
		
		
		
		methodB();
	}
}

運行結果:

進入方法A
用A方法的finally
製造異常
進入方法B
調用B方法的finally

題目二:

package com.atguigu.java1;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

import org.junit.Test;

/*
 * try-catch-finally中finally的使用：
 * 
 * 
 * 1.finally是可選的
 * 
 * 2.finally中聲明的是一定會被執行的代碼。即使catch中又出現異常了，try中有return語句，catch中有
 * return語句等情況。
 * 
 * 3.像數據庫連接、輸入輸出流、網絡編程Socket等資源，JVM是不能自動的回收的，我們需要自己手動的進行資源的
 *   釋放。此時的資源釋放，就需要聲明在finally中。
 * 
 * 
 * 
 */
 
 
	@Test
	public void testMethod(){
		int num = method();
		System.out.println(num);
	}
	
	public int method(){
		
		try{
			int[] arr = new int[10];
			System.out.println(arr[10]);
			return 1;
		}catch(ArrayIndexOutOfBoundsException e){
			e.printStackTrace();
			return 2;
		}finally{
			System.out.println("我一定會被執行");
			return 3;
		}
		
		
	}
	 

運行結果:

java.lang.ArrayIndexOutOfBoundsException: Index 10 out of bounds for length 10
	at com.atguigu.java1.FinallyTest.method(FinallyTest.java:67)
	at com.atguigu.java1.FinallyTest.testMethod(FinallyTest.java:59)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:89)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
我一定會被執行
3