try--catch--finally

a.try和catch总有一个要执行；
b.finally总在try或者catch之后执行；
c.某一层捕获了异常，这一层的try代码区中出现异常之后的代码将不被执行

import java.io.File;
import java.io.FileNotFoundException;

public class TestException {

	public static void main(String[] args) {
	   new AA().test1();
	}
}

class AA {

	public int test1(){
		try {
			int j= new AA().test2();
			System.out.println("try  of ...test1");
			return j;
		} catch (Exception e) {
			System.out.println("catch  of ...test1");
			e.printStackTrace();
			return 0;
		} finally {
			System.out.println("finally of ...test1");
		}
	}
	public int test2() {
		try {
			int i = 2 / 0;
			System.out.println("try  of ...test2");//该层捕获了异常，则在异常代码之后的代码将不被执行
			return i;
			
		} catch (Exception e) {
			System.out.println("catch  of ...test2");
			e.printStackTrace();
			return 0;
		} finally {
			System.out.println("finally  of ...test2");
		}
		
	}
}

输出:
catch  of ...test2
finally  of ...test2
try  of ...test1
finally of ...test1

import java.io.File;
import java.io.FileNotFoundException;

public class TestException {

	public static void main(String[] args) {
	   new AA().test1();
	}
}

class AA {

	public int test1(){
		try {
			//该层捕获了异常，则在异常代码之后的代码将不被执行
			int j= new AA().test2();
			System.out.println("try  of ...test1");
			return j;
		} catch (Exception e) {
			System.out.println("catch  of ...test1");
			e.printStackTrace();
			return 0;
		} finally {
			System.out.println("finally of ...test1");
		}
	}
	public int test2() {
		try {
			int i = 2 / 0;
			System.out.println("try  of ...test2");
			return i;
			
		} /*catch (Exception e) {
			System.out.println("catch  of ...test2");
			e.printStackTrace();
			return 0;
		}*/ finally {
			System.out.println("finally  of ...test2");
		}
		
	}
}

输出：
finally  of ...test2
catch  of ...test1
finally of ...test1