Java IO 写入文件

之前我们看过如何在 Java中创建一个文件。在本教程中,我们将看到如何使用FileOutputStream在 java 中写入文件。我们将使用FileOutputStreamwrite()方法将内容写入指定的文件。这是write()方法的签名。

public void write(byte[] b) throws IOException

它将指定字节数组中的b.length字节写入此文件输出流。如您所见,此方法需要字节数组才能将它们写入文件。因此,在将内容写入文件之前,我们需要将内容转换为字节数组。

完整代码:写入文件

在下面的例子中,我们将String写入文件。要将String转换为字节数组,我们使用String类的getBytes()方法。

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

public class WriteFileDemo {
   public static void main(String[] args) {
      FileOutputStream fos = null;
      File file;
      String mycontent = "This is my Data which needs" +
         " to be written into the file";
      try {
          //Specify the file path here
      file = new File("C:/myfile.txt");
      fos = new FileOutputStream(file);

          /* This logic will check whether the file
       * exists or not. If the file is not found
       * at the specified location it would create
       * a new file*/
      if (!file.exists()) {
         file.createNewFile();
      }

      /*String content cannot be directly written into
       * a file. It needs to be converted into bytes
       */
      byte[] bytesArray = mycontent.getBytes();

      fos.write(bytesArray);
      fos.flush();
      System.out.println("File Written Successfully");
       } 
       catch (IOException ioe) {
      ioe.printStackTrace();
       } 
       finally {
      try {
         if (fos != null) 
         {
         fos.close();
         }
          } 
      catch (IOException ioe) {
         System.out.println("Error in closing the Stream");
      }
       }
   }
}

输出:

File Written Successfully
赞(0)

评论 抢沙发

  • 昵称 (必填)
  • 邮箱 (必填)
  • 网址