JAVA - 非可写通道异常

public FileProcessor(String filenameIn, String fileModeIn){ 
     try { 
      randomaccessfile = new RandomAccessFile(filenameIn, fileModeIn); 
      fileChannel = randomaccessfile.getChannel(); 
      buffer = fileChannel.map(FileChannel.MapMode.READ_WRITE, 0, fileChannel.size()); 
     } catch (FileNotFoundException e) { 
      System.err.println("Error while creating a File"); 
      e.printStackTrace(); 
      System.exit(1); 
     } catch (IOException e) { 
      System.err.println("Error while creating MappedByteBuffer"); 
      e.printStackTrace(); 
      System.exit(1); 
     }

异常线程 “main” java.nio.channels.NonWritableChannelException 在sun.nio.ch.FileChannelImpl.map（FileChannelImpl.java:880）JAVA - 非可写通道异常

获取NonwritableChannelException为上面的代码。请帮忙。谢谢。！！

来源

2016-11-14 ShreyasMN

什么是你的fileModeIn？ – developer

我得到一个文件模式作为输入，但默认设置为READ_WRITE – ShreyasMN

当我的最后一个小型可重复程序在fileModeIn和FileChannel.MapMode.READ_WRITE不匹配的时候出现错误。

样例程序：

import java.io.*; 
import java.nio.channels.*; 
import java.nio.MappedByteBuffer; 
class SampleFileProcessor { 
    public static void main(String[] args) { 
     String fileName = args[0]; 
     String mode = args[1]; 
     JFP jf = new JFP(); 
     jf.FileProcessor(fileName,mode); 
    } 

    public void FileProcessor(String filenameIn, String fileModeIn){ 
     try { 
      RandomAccessFile randomaccessfile = new RandomAccessFile(filenameIn, fileModeIn); 
      FileChannel fileChannel = randomaccessfile.getChannel(); 
      MappedByteBuffer buffer = fileChannel.map(FileChannel.MapMode.READ_WRITE, 0, fileChannel.size()); 
     } catch (FileNotFoundException e) { 
      System.err.println("Error while creating a File"); 
      e.printStackTrace(); 
      System.exit(1); 
     } catch (IOException e) { 
      System.err.println("Error while creating MappedByteBuffer"); 
      e.printStackTrace(); 
      System.exit(1); 
     } 
    } 
}

输入输出&：

echo "Non-matching fileModeIn and FileChannel.MapMode" 
java SampleFileProcessor input_file.txt r 
Exception in thread "main" java.nio.channels.NonWritableChannelException 
    at sun.nio.ch.FileChannelImpl.map(FileChannelImpl.java:799) 
    at JFP.FileProcessor(JFP.java:19) 
    at JFP.main(JFP.java:9) 
<Error> 

echo "Matching fileModeIn and FileChannel.MapMode" 
java SampleFileProcessor input_file.txt rw 
<Success>

来源

2016-11-15 01:25:06 learningloop

如果你想READ_WRITE映射文件，当您创建RandomAccessFile你最终从得到它时需要"rw" ..

来源

2016-11-15 01:52:46 EJP

JAVA - 非可写通道异常

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