java.util.zip.CheckedInputStream.read() 方法示例

说明

java.util.zip.CheckedInputStream.read() 方法返回此输入流的校验和。

声明

以下是 java.util.zip.CheckedInputStream.read() 方法的声明。

public int read()
   throws IOException

返回

已读取字节或流已结束时返回 -1。

异常

• IOException − 如果发生 I/O 错误。

先决条件

使用以下内容在 D: > test > 目录中创建文件 Hello.txt。

This is an example.

示例

以下示例说明了 java.util.zip.CheckedInputStream.read() 方法的用法。

package com.tutorialspoint;

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.Adler32;
import java.util.zip.CheckedInputStream;
import java.util.zip.CheckedOutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;

public class CheckedInputStreamDemo {
   private static String SOURCE_FILE = "D:\\test\\Hello.txt";
   private static String TARGET_FILE = "D:\\test\\Hello.zip";

   public static void main(String[] args) {
      try {
 
         createZipFile();
 
         FileInputStream fin= new FileInputStream(TARGET_FILE);
         CheckedInputStream checksum = new CheckedInputStream(fin, new Adler32());
         while(checksum.read() >= 0){        
 
         } 

         System.out.println("Checksum: " + checksum.getChecksum().getValue());      
      } catch(IOException ioe) {
         System.out.println("IOException : " + ioe);
      }
   }
   
   private static void createZipFile() throws IOException{
      FileOutputStream fout = new FileOutputStream(TARGET_FILE);
      CheckedOutputStream checksum = new CheckedOutputStream(fout, new Adler32());
      ZipOutputStream zout = new ZipOutputStream(checksum);

      FileInputStream fin = new FileInputStream(SOURCE_FILE);
      zout.putNextEntry(new ZipEntry(SOURCE_FILE));
      int length;
      byte[] buffer = new byte[1024];
      while((length = fin.read(buffer)) > 0) {
         zout.write(buffer, 0, length);
      }

      zout.closeEntry();
      fin.close();
      zout.close();
   }
}

我们来编译并运行上面的程序，这将生成以下结果 −

Checksum: 1400120861