finally在try和catch块以及return中的执行顺序

执行顺序

无catch时

• finally会在try包含的return之后执行，会在try外面的return之前执行

当有catch时

• finally是在catch执行之后catch包含的return之前执行的

执行顺序图

try包含的return
|
v
catch
|
v
finally
|
v
catch包含的return
|
v
try外面的return（和catch块不能并存）

DEMO验证

package abc;

/** 
 * @ClassName: Test1 
 * @Description: TODO(这里用一句话描述这个类的作用) 
 * @author  bamboo   <a href="mailto:zjcjava@163.com?subject=hello,bamboo&body=Dear Bamboo:%0d%0a描述你的问题：">Bamboo</a>
 * @date 2017年3月2日 下午2:49:55 
 * @since
 */

public class Test1 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        testa();
    }


    public static  Object testa() {
        // TODO Auto-generated method stub
         StringBuffer sb = new StringBuffer("");

            try {
                return print(sb);
            } finally {
                sb.append("finally");
                System.out.println(sb.toString());
            }
    }

    public static  Object testb() {
        // TODO Auto-generated method stub
         StringBuffer sb = new StringBuffer("");

            try {

            } finally {
                sb.append("finally");
                System.out.println(sb.toString());
            }
            return print(sb);
    }

    public static  Object testc() {
        // TODO Auto-generated method stub
         StringBuffer sb = new StringBuffer("");

            try {

                int a=1;
                if(1==a){
                    throw new Exception();
                }
                return print(sb);
            }catch(Exception e){
                sb.append("catch");
                return print(sb);
            }finally {
                sb.append("finally");
                System.out.println(sb.toString());
            }
    }
    public static  Object print(StringBuffer sb) {
        // TODO Auto-generated method stub
            sb.append("return");
          System.out.println(sb.toString());

          return null;
    }
}

testa()方法ouput:

return
returnfinally

testa()方法是return在try的里面，从结果看先执行的retrun然后执行的finally;

testb()方法ouput:

finally
finallyreturn

testb()方法是return在try的外面，从结果看先执行的finally然后执行的retrun;

testc()方法ouput:

catchreturn
catchreturnfinally

testb()方法是return在try的外面，从结果看先执行的finally然后执行的retrun;

参考资料

http://www.ibm.com/developerworks/cn/java/j-lo-finally/
finally对基本类型和引用类型参数造成的影响
http://blog.youkuaiyun.com/imzoer/article/details/8037970