全面了解java byte數組與文件讀寫
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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>//第一種獲取文件內容方式 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; } // 確保所有數據均被讀取 if (offset != buffer.length) { throw new IOException("Could not completely read file " + file.getName()); } fi.close(); return buffer; } //第二種獲取文件內容方式 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; } //將byte數組寫入文件 public void createFile(String path, byte[] content) throws IOException { FileOutputStream fos = new FileOutputStream(path); fos.write(content); fos.close(); }} |
以上這篇全面了解java byte數組與文件讀寫就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支持服務器之家。
