try catch finally的执行顺序

Java try-catch-finally详解

最新推荐文章于 2025-04-09 08:10:26 发布

原创最新推荐文章于 2025-04-09 08:10:26 发布 · 150 阅读

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本文详细解析了Java中try-catch-finally语句的执行流程与特性，特别是finally块无论异常是否发生都会被执行的特点，并通过具体示例展示了不同情况下程序的运行结果。

1.try catch finally中的finally不管在什么情况之下都会执行，执行的时间是在程序return之前。

2.Java编译器不允许有显示的执行不到的语句块，比如return之后就不可能再有别的语句块（分支不属于此列），所以以下程序编译会报错：

package com.practice.model;

public class Test {
	public String testSeq() {
		String result="end";
		int i = 0;
		try {
			System.out.println(6/i);
//			System.out.println(i);
			System.out.println("in try...");
			return result;
		} catch (Exception e) {
			e.printStackTrace();
			System.out.println("In catch...");
			return result;
		} finally {
			System.out.println("In finally....");
//			return result;
		}
		return result;
	}
	
	public static void main(String[] args){
		Test test=new Test();
		String rs=test.testSeq();
		System.out.println("result = "+rs);
	}

}

原因是由于try{...}catch{...}块中都已存在return。

3.以下是几个小例子：

package com.practice.model;

public class Test {
	public String testSeq() {
		String result1="Normal";
        String result2="Exception";
		int i = 0;
		try {
//			System.out.println(6/i);
			System.out.println(i);
			System.out.println("in try...");
			return result1;
		} catch (Exception e) {
			e.printStackTrace();
			System.out.println("In catch...");
			return result2;
		} finally {
			System.out.println("In finally....");
		}
	}
	
	public static void main(String[] args){
		Test test=new Test();
		String rs=test.testSeq();
		System.out.println("result = "+rs);
	}

}

执行结果是：

0
in try...
In finally....
result = Normal

package com.practice.model;

public class Test {
	public String testSeq() {
		String result1="Normal";
        String result2="Exception";
		int i = 0;
		try {
			System.out.println(6/i);
//			System.out.println(i);
			System.out.println("in try...");
			return result1;
		} catch (Exception e) {
			e.printStackTrace();
			System.out.println("In catch...");
			return result2;
		} finally {
			System.out.println("In finally....");
		}
	}
	
	public static void main(String[] args){
		Test test=new Test();
		String rs=test.testSeq();
		System.out.println("result = "+rs);
	}

}

执行结果是：

java.lang.ArithmeticException: / by zero
	at com.practice.model.Test.testSeq(Test.java:9)
	at com.practice.model.Test.main(Test.java:24)
In catch...
In finally....
result = Exception