如何将此 try-finally 更改为 try-with-resources？

Posted 2023-03-25

【中文标题】如何将此 try-finally 更改为 try-with-resources？

【英文标题】：How do I change this try-finally to try-with-resources?

【发布时间】：2021-03-11 17:44:51

【问题描述】：

这是代码。 大多数示例不允许我使用通过函数参数获得的响应变量。 有没有人可以帮助我解决这个问题？ 还是在这种情况下使用 try-finally 比 try-with-resources 更好？

    public void func(HttpServletResponse response) throws IOException 
            OutputStream out = null;
            InputStream in = null;
    
            try 
                out = response.getOutputStream();
                ResponseEntity<Resource> url = getUrl();
    
                Resource body = url.getBody();
                in = body.getInputStream();
    
                FileCopyUtils.copy(in, out);
    
             finally 
                if (out != null) 
                    try 
                        out.close();
                    catch (IOException e) 
                    
                
                if (in != null) 
                    try 
                        in.close();
                    catch (IOException e) 
                    
                
            
        

【参考方案1】：

您可以使用try-with-resources 构造来做到这一点

public void func(HttpServletResponse response) throws IOException 
   

        try (OutputStream out = response.getOutputStream) 
            out = response.getOutputStream();
            ResponseEntity<Resource> url = getUrl();

            Resource body = url.getBody();
            try(InputStream in = body.getInputStream()) 

                FileCopyUtils.copy(in, out);