Java 操作 文件 File

写文件

public void writeFile2(String saveFile,String  readFilePath) throws IOException{
		FileWriter fw = null; 
		//追加写
		fw = new FileWriter(saveFile,true);
		// 
		 
		 Long startTime = System.currentTimeMillis();  
	        BufferedReader reader = getReader(new File(readFilePath));  
	  
	        String line; 
	  
	        while ((line = reader.readLine()) != null) {  
	            // 空转  
	        	//System.out.println(line);
	        	fw.write(line);  
	        }  
	        Long estimatedTime = System.currentTimeMillis() - startTime;  
	          
	        fw.close(); 
	

	}

  

 

 

读文件

	public static void stream(String file) throws FileNotFoundException, IOException {  
        Long startTime = System.currentTimeMillis();  
        BufferedReader reader = getReader(new File(file));  
  
        String line; 
       
        while ((line = reader.readLine()) != null) {  
            // 空转  
        	System.out.println(line);
         
        }  
        Long estimatedTime = System.currentTimeMillis() - startTime;  
        System.out.printf("stream Diff: %d ms\n", estimatedTime);  
  
    } 

 public static BufferedReader getReader(File f) throws FileNotFoundException, IOException {  
        BufferedReader reader = null;  
        if (f.getName().endsWith(".gz")) {  
            reader = new BufferedReader(new InputStreamReader(new GZIPInputStream(new FileInputStream(f))));  
        } else {  
            reader = new BufferedReader(new InputStreamReader(new FileInputStream(f)));  
        }  
        return reader;  
    }