FileReader 및 BufferedReader + (Scanner)

 

종료시 close는 반드시 호출할 수 있도록 하며, try ~ finally 구문에 넣어주는 것이 좋다.
자세한 내용은 예제를 통해 참조

ex)

public class StreamTest {
	
	
	
	public StreamTest() {
		super();
		this.test();
	}

	private void test() {
		String fullPath = "C:"+File.separator+"Users"+File.separator+"Lee"+File.separator+"test"+File.separator+"numbers.txt";
		//writeFile(fullPath,10);
		readFile(fullPath);
	}

	private void writeFile(String fullPath, int i) {
		FileWriter fileWriter=null;
		BufferedWriter bufferedWriter=null;
		
		try {
			//fileWriter= new FileWriter(fullPath); //write mode.
			fileWriter= new FileWriter(fullPath, true);//append mode
			bufferedWriter = new BufferedWriter(fileWriter);
			
			for ( int loop=0; loop < i ; loop ++) {
				bufferedWriter.write(Integer.toString(loop));
				bufferedWriter.newLine();
			}
		
			System.out.println("Write done!");
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			
		} finally {
			
			if( bufferedWriter!=null) {
				try {
					bufferedWriter.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			} 
			
			if (fileWriter != null) {
				
				try {
					fileWriter.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}
		private void readFile(String fullPath) {
			FileReader fileReader=null;
			BufferedReader bufferedReader=null;
			
			try {
				//
				fileReader= new FileReader(fullPath);
				bufferedReader = new BufferedReader (fileReader);
				
				String data;
				
				while((data = bufferedReader.readLine()) != null ){
					System.out.println(data);
				}
			
				System.out.println("Read done!");
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
				
			} finally {
				
				if( bufferedReader!=null) {
					try {
						bufferedReader.close();
					} catch (IOException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				} 
				
				if (fileReader != null) {
					
					try {
						fileReader.close();
					} catch (IOException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}
			}
			
			
			
			
		}

		private void readFileWithScanner( String fileName) {
				
			File file = new File(fileName);
			
			Scanner scanner = null;
			
			try {
				scanner = new Scanner(file);
				while (scanner.hasNextLine()) {
					System.out.println(scanner.nextLine());
				}
				
			} catch (FileNotFoundException e) {
				e.printStackTrace();
			} finally {
				if (scanner != null)
					scanner.close();
			}
			
            
            
            /* 이하 동일, 참조
            		
			try {
				String data = new String(Files.readAllBytes(Paths.get(fileName)));
				System.out.println(data);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();				
			}
            
            */

		}
        
        
        	
}

 

 

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