全面了解java byte数组与文件读写

全面了解java byte数组与文件读写

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

public class FileHelper {
<span style="white-space:pre">  </span>//第一种获取文件内容方式
  public byte[] getContent(String filePath) throws IOException {
    File file = new File(filePath);

    long fileSize = file.length();
    if (fileSize > Integer.MAX_VALUE) {
      System.out.println("file too big...");
      return null;
    }

    FileInputStream fi = new FileInputStream(file);

    byte[] buffer = new byte[(int) fileSize];

    int offset = 0;

    int numRead = 0;

    while (offset < buffer.length

    && (numRead = fi.read(buffer, offset, buffer.length - offset)) >= 0) {

      offset += numRead;

    }

    // 确保所有数据均被读取

    if (offset != buffer.length) {

      throw new IOException("Could not completely read file "
          + file.getName());

    }

    fi.close();

    return buffer;
  }

  //第二种获取文件内容方式
  public byte[] getContent2(String filePath) throws IOException
  {
    FileInputStream in=new FileInputStream(filePath);

    ByteArrayOutputStream out=new ByteArrayOutputStream(1024);

    System.out.println("bytes available:"+in.available());

    byte[] temp=new byte[1024];

    int size=0;

    while((size=in.read(temp))!=-1)
    {
      out.write(temp,0,size);
    }

    in.close();

    byte[] bytes=out.toByteArray();
    System.out.println("bytes size got is:"+bytes.length);

    return bytes;
  }
    //将byte数组写入文件
  public void createFile(String path, byte[] content) throws IOException {

    FileOutputStream fos = new FileOutputStream(path);

    fos.write(content);
    fos.close();
  }

}

以上这篇全面了解java byte数组与文件读写就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持服务器之家。