public boolean save(String filename){
	/*
	* 保存文件
	*/
	try{
		File file = new File(path + filename);
		...

		// 未产生异常
		return true;
	} catch (FileNotFoundException e){
		// 产生异常
		return false;
	}
}

public void save(String filename) throws FileNotFoundException{
	File file = new File(path + filename);
	...
}

public class Test {
	
	private String name;							

	private class Test1{

		public void sayHello(){
			System.out.println("Hello, My name is " + name);		// 会报错
		}

	}
}

public class Test {
	
	private final String name;		// 加上了 final 关键字修饰	

	private class Test1{

		public void sayHello(){
			System.out.println("Hello, My name is " + name);		
		}

	}
}