Java RandomAccessFile.readLine方法代码示例

import java.io.RandomAccessFile; //导入方法依赖的package包/类
public void readFromFileUsingLoop() {
    try {
        RandomAccessFile randomAccessFile = new RandomAccessFile("input.txt", "r");
        String line;

        while (true) {
            line = randomAccessFile.readLine();
            if (line == null) {
                break;
            }
            System.out.println(line);
        }

    } catch (FileNotFoundException fnfe) {
        System.out.println("Could not find the input file");
    } catch (IOException ioe) {
        System.out.println("Can't read anymore!");
    }

}
 

import java.io.RandomAccessFile; //导入方法依赖的package包/类
private void parsePTS(File pts) {
    try {
        RandomAccessFile temp = new RandomAccessFile(pts, "r");
        String line = null;
        this.gcps = new ArrayList<Gcp>();
        while ((line = temp.readLine()) != null) {
            String[] nums = line.split(" ");
            if (nums.length == 4) {
                Gcp gcp = new Gcp();
                gcp.setXgeo(Double.parseDouble(nums[0]));
                gcp.setYgeo(Double.parseDouble(nums[1]));
                gcp.setXpix(Double.parseDouble(nums[2]));
                gcp.setYpix(Double.parseDouble(nums[3]));
                gcps.add(gcp);
            }
        }
        temp.close();
    } catch (Exception ex) {
    	logger.error(ex.getMessage(),ex);
    }
}
 

import java.io.RandomAccessFile; //导入方法依赖的package包/类
public void readUsingRandomAccessFile() {
    try {
        RandomAccessFile randomAccessFile = new RandomAccessFile("input.txt", "r");
        int x = Integer.parseInt(randomAccessFile.readLine());
        double y = Double.parseDouble(randomAccessFile.readLine());
        String s = randomAccessFile.readLine();
        System.out.println(x);
        System.out.println(y);
        System.out.println(s);
    } catch (FileNotFoundException fnfe) {
        System.out.println("Could not find the input file");
    } catch (IOException ioe) {
        System.out.println("Can't read anymore!");
    }

}
 

import java.io.RandomAccessFile; //导入方法依赖的package包/类
/**
 * get the next Packet from the RandomAccessFile
 * 
 * @param raf
 * @return - the Packet
 * @throws Exception
 */
public PacketSeek nextPacket(RandomAccessFile raf) throws Exception {
  String line = null;
  int count = 0;
  long pos = raf.getFilePointer();
  while ((line = raf.readLine()) != null) {
    Packet p = LogReader.lineAsPacket(line);
    if (p != null) {
      PacketSeek packetSeek = new PacketSeek();
      packetSeek.packet = p;
      packetSeek.pos = pos;
      return packetSeek;
    }
    pos = raf.getFilePointer();
    if (checkCountLimit("line", count++, false))
      return null;
  } // while
  return null;
}
 

import java.io.RandomAccessFile; //导入方法依赖的package包/类
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
   private long getSizeTotalRAM(boolean isTotal) {
	long sizeInBytes = 1000;
	MemoryInfo mi = new MemoryInfo();
	activityManager.getMemoryInfo(mi);
	if(isTotal) {
		try { 
			if(Utils.hasJellyBean()){
				long totalMegs = mi.totalMem;
				sizeInBytes = totalMegs;
			}
			else{
				RandomAccessFile reader = new RandomAccessFile("/proc/meminfo", "r");
				String load = reader.readLine();
				String[] totrm = load.split(" kB");
				String[] trm = totrm[0].split(" ");
				sizeInBytes=Long.parseLong(trm[trm.length-1]);
				sizeInBytes=sizeInBytes*1024;
				reader.close();	
			}
		} 
		catch (Exception e) { }
	}
	else{
		long availableMegs = mi.availMem;
		sizeInBytes = availableMegs;
	}		
	return sizeInBytes;
}
 

import java.io.RandomAccessFile; //导入方法依赖的package包/类
public void parseConfigFile(String scenarioListFile) throws Exception {
	if (!new File(scenarioListFile).exists())
		throw new Exception(scenarioListFile + " does not exit");

	try {
		RandomAccessFile raf = new RandomAccessFile(scenarioListFile, "r");

		String line = "";
		while (line != null) {
			line = raf.readLine();

			if (line == null)
				break;
			if (line.startsWith("#"))
				continue;

			String trimmedLine = line.trim();
			if (trimmedLine.length() == 0)
				continue;

			run(trimmedLine);
		}

		raf.close();
	}
	catch (IOException e) {
		e.printStackTrace();
	}
}
 

import java.io.RandomAccessFile; //导入方法依赖的package包/类
public int countLines(String filename) {
    int count = 0;
    
    try {
        RandomAccessFile input = new RandomAccessFile(filename, "r");
        
        String line;
        while ((line = input.readLine()) != null) {
            count++;
        }
        
        /*
        while (true) {
            String line = input.readLine();
            if (line == null)
                break;
            count++;
        }
        */
    } catch (FileNotFoundException fnfe) {

    } catch (IOException ioe) {
        
    }
    
    return count;
}
 

import java.io.RandomAccessFile; //导入方法依赖的package包/类
/**
 * Attempts to acquire an exclusive lock on the storage.
 * 
 * @return A lock object representing the newly-acquired lock or
 * <code>null</code> if storage is already locked.
 * @throws IOException if locking fails.
 */
@SuppressWarnings("resource")
FileLock tryLock() throws IOException {
  boolean deletionHookAdded = false;
  File lockF = new File(root, STORAGE_FILE_LOCK);
  if (!lockF.exists()) {
    lockF.deleteOnExit();
    deletionHookAdded = true;
  }
  RandomAccessFile file = new RandomAccessFile(lockF, "rws");
  String jvmName = ManagementFactory.getRuntimeMXBean().getName();
  FileLock res = null;
  try {
    res = file.getChannel().tryLock();
    if (null == res) {
      throw new OverlappingFileLockException();
    }
    file.write(jvmName.getBytes(Charsets.UTF_8));
    LOG.info("Lock on " + lockF + " acquired by nodename " + jvmName);
  } catch(OverlappingFileLockException oe) {
    // Cannot read from the locked file on Windows.
    String lockingJvmName = Path.WINDOWS ? "" : (" " + file.readLine());
    LOG.error("It appears that another node " + lockingJvmName
        + " has already locked the storage directory: " + root, oe);
    file.close();
    return null;
  } catch(IOException e) {
    LOG.error("Failed to acquire lock on " + lockF
        + ". If this storage directory is mounted via NFS, " 
        + "ensure that the appropriate nfs lock services are running.", e);
    file.close();
    throw e;
  }
  if (!deletionHookAdded) {
    // If the file existed prior to our startup, we didn't
    // call deleteOnExit above. But since we successfully locked
    // the dir, we can take care of cleaning it up.
    lockF.deleteOnExit();
  }
  return res;
}
 

import java.io.RandomAccessFile; //导入方法依赖的package包/类
/**
 * Get max cpu rate.
 *
 * This works by examining the list of CPU frequencies in the pseudo file
 * "/sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state" and how much time has been spent
 * in each. It finds the highest non-zero time and assumes that is the maximum frequency (note
 * that sometimes frequencies higher than that which was designed can be reported.) So it is not
 * impossible that this method will return an incorrect CPU frequency.
 *
 * Also note that (obviously) this will not reflect different CPU cores with different
 * maximum speeds.
 *
 * @return cpu frequency in MHz
 */
public static int getMaxCPUFreqMHz() {

    int maxFreq = -1;
    try {

        RandomAccessFile reader = new RandomAccessFile( "/sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state", "r" );

        boolean done = false;
        while ( ! done ) {
            String line = reader.readLine();
            if ( null == line ) {
                done = true;
                break;
            }
            String[] splits = line.split( "\\s+" );
            assert ( splits.length == 2 );

            int timeInState = Integer.parseInt( splits[1] );
            if ( timeInState > 0 ) {
                int freq = Integer.parseInt( splits[0] ) / 1000;
                System.out.println("maxFreq = " + freq);
                if ( freq > maxFreq ) {
                    maxFreq = freq;
                }
            }
        }

    } catch ( IOException ex ) {
        ex.printStackTrace();
    }

    return maxFreq;
}
 

import java.io.RandomAccessFile; //导入方法依赖的package包/类
public static List<List<String>> getSample(FileInput input, long numSamples){
  input.getFileName();
  File file = new File(input.getFileName());
  long length = file.length();
  Set<List<String>> set = new HashSet<>();
  Random rnd = new Random();

  while (set.size() < numSamples) {
    try {
      RandomAccessFile rndFile = new RandomAccessFile(file, "r");
      long randomPosition = (long)(rnd.nextDouble()*(length));
      rndFile.seek(randomPosition);
      rndFile.readLine();
      String line = rndFile.readLine();
      if(line == null) continue;
      Reader in = new StringReader(line);
      CSVReader csvReader = new CSVReader(in,
                                          input.getSeparatorAsChar(),
                                          input.getQuoteCharAsChar(),
                                          input.getEscapeCharAsChar(),
                                          input.getSkipLines(),
                                          input.isStrictQuotes(),
                                          input.isIgnoreLeadingWhiteSpace());
      String[] values = csvReader.readNext();
      List<String> valueList = new ArrayList<>();
      for (String val : values) {
        if (val.equals("")) {
          valueList.add(null);
        } else {
          valueList.add(val);
        }
        if (!set.contains(valueList))
          set.add(valueList);
      }
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
  //Todo: return value - + wrapper for interface compatibility
  return new ArrayList<>(set);
}
 

import java.io.RandomAccessFile; //导入方法依赖的package包/类
public void runScript(String file) throws Exception {
    RandomAccessFile raf = new RandomAccessFile(file, "r");
    String line = null;
    try{
     while ((line = raf.readLine()) != null) {
         String[] command = line.split(" ");
         for (String c : pl.getCommands()) {
             if (c.startsWith(command[0])) {
                 String[] args = new String[command.length - 1];
                 for (int i = 1; i < command.length; i++) {
                     args[i - 1] = command[i];
                 }
                 try {
                     Object a = pl.getActions().get(c);//Class.forName(actions.get(c).getClassName()).newInstance();
                     if (!(a instanceof IConsoleAction)) {
                         return;
                     }
                     SumoAbstractAction ica = (SumoAbstractAction) a;
                     //if (ica instanceof IProgressListener) {
                         currentAction = (SumoAbstractAction) ica;
                         if (ica.execute()) {
                             return;
                         }
                         while (currentAction != null && !currentAction.isDone()) {
                             Thread.sleep(1000);
                         }
                     /*} else {
                         if (!ica.execute()) {
                             return;
                         }
                     }*/
                 	return;
                 } catch (Exception e) {
                     e.printStackTrace();
                     return;
                 }
             }
         }
         Thread.sleep(1000);
     }
    }finally{
    	raf.close();
    }
}