如何关闭Java中

Question

文件这是我的代码：

FileWriter fw = new FileWriter(log,true); 
BufferedWriter bw = new BufferedWriter(fw); 
StringWriter sw = new StringWriter(); 
PrintWriter pw = new PrintWriter(sw); 

fw.close(); 
bw.close(); 
sw.close(); 
pw.close(); 

我想改变它的东西是这样的：

BufferedWriter bw = new BufferedWriter(new FileWriter(log,true)); 
PrintWriter pw = new PrintWriter(new StringWriter()); 

bw.close(); 
pw.close(); 

请问这是正确的，否则将丢失的close()电话导致问题？

Answer 1

可以肯定的结束之时不会忘记你可以使用try-with-resource声明

try (BufferedWriter bw = new BufferedWriter(new FileWriter(log, true)); 
     PrintWriter pw = new PrintWriter(new StringWriter())) { 
    // do your processing here 
} catch (IOException ex) { 
    // do your exception handling 
} 

编译器将为您添加close()的相应代码。

Answer 2

当您关闭的BufferedWriter对象，这需要的FileWriter对象在其构造，那么隐含的FileWriter的对象也被关闭。

因此，要回答你的问题，两种方式都很好，并同它不作任何问题

Previous Answer

Best practice

Answer 3

自Java 7以来，您可以让java自动关闭您的资源。看看try with resources。

try (BufferedReader br = new BufferedReader(new FileReader(path))) { 
    return br.readLine(); 
}