在 FileWriter 上使用 try catch
Using try catch on FileWriter
我有一个关于 FileNotFoundExcpetion 的问题。我得到的接口定义了方法名,包括 "throws FileNotFoundExcpetion".
public static void writeAssignment(ArrayList<String> assignment, String filename) throws FileNotFoundException {
try {
FileWriter writer = new FileWriter(filename);
for (String str : assignment) {
writer.write(str + "\n");
}
writer.close();
} catch (IOException e) {
System.err.print("Something went wrong");
}
}
这是处理异常的正确方法吗?当我写入我用文件编写器创建的文件时,如果我在方法中创建文件,怎么可能找不到文件??
IOException
是 FileNotFoundException
的超级 class。因此,IOException
的 catch 块也会捕获每个 FileNotFoundException
.
您应该按如下方式实现功能:
public static void writeAssignment(ArrayList<String> assignment, String filename) throws FileNotFoundException {
try (FileWriter writer = new FileWriter(filename)) {
for (String str : assignment) {
writer.write(str + "\n");
}
} catch (FileNotFoundException e) {
throw e; // catch and re-throw
} catch (IOException e) {
System.err.print("Something went wrong");
}
}
您可以捕获异常而不是 IOException
public static void writeAssignment(ArrayList<String> assignment, String filename) throws FileNotFoundException {
try {
FileWriter writer = new FileWriter(filename);
for (String str : assignment) {
writer.write(str + "\n");
}
writer.close();
} catch (Exception e) {
e.printStackTrace();
}
}
通过这种类型编码,您可以see/learn 异常的层次结构。
如果你想执行你的程序,无论是否捕获异常,你可以使用 finally 块。你将在哪里关闭你的作家。
我有一个关于 FileNotFoundExcpetion 的问题。我得到的接口定义了方法名,包括 "throws FileNotFoundExcpetion".
public static void writeAssignment(ArrayList<String> assignment, String filename) throws FileNotFoundException {
try {
FileWriter writer = new FileWriter(filename);
for (String str : assignment) {
writer.write(str + "\n");
}
writer.close();
} catch (IOException e) {
System.err.print("Something went wrong");
}
}
这是处理异常的正确方法吗?当我写入我用文件编写器创建的文件时,如果我在方法中创建文件,怎么可能找不到文件??
IOException
是 FileNotFoundException
的超级 class。因此,IOException
的 catch 块也会捕获每个 FileNotFoundException
.
您应该按如下方式实现功能:
public static void writeAssignment(ArrayList<String> assignment, String filename) throws FileNotFoundException {
try (FileWriter writer = new FileWriter(filename)) {
for (String str : assignment) {
writer.write(str + "\n");
}
} catch (FileNotFoundException e) {
throw e; // catch and re-throw
} catch (IOException e) {
System.err.print("Something went wrong");
}
}
您可以捕获异常而不是 IOException
public static void writeAssignment(ArrayList<String> assignment, String filename) throws FileNotFoundException {
try {
FileWriter writer = new FileWriter(filename);
for (String str : assignment) {
writer.write(str + "\n");
}
writer.close();
} catch (Exception e) {
e.printStackTrace();
}
}
通过这种类型编码,您可以see/learn 异常的层次结构。 如果你想执行你的程序,无论是否捕获异常,你可以使用 finally 块。你将在哪里关闭你的作家。