Hadoop系列修炼笔记12
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2022-07-08 12:03:11
核心内容:压缩和解压缩的代码
package com.shujuelin.hdfs.mr.compress;
import org.apache.hadoop.conf.Confi...
核心内容:压缩和解压缩的代码
package com.shujuelin.hdfs.mr.compress; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.io.IOUtils; import org.apache.hadoop.io.compress.*; import org.apache.hadoop.util.ReflectionUtils; import org.junit.Test; import java.io.FileInputStream; import java.io.FileOutputStream; /** * 测试压缩 */ public class TextCompress { public static void main(String[] args) throws Exception { Class[] zipClasses = { DeflateCodec.class, GzipCodec.class, BZip2Codec.class, Lz4Codec.class, SnappyCodec.class }; for(Class c : zipClasses){ //unzip(c); zip(c); } } /** * 压缩测试 */ public static void zip(Class codecClass) throws Exception { long start = System.currentTimeMillis(); //实例化对象CompressionCodec:压缩编解码器 CompressionCodec codec = (CompressionCodec) ReflectionUtils.newInstance(codecClass, new Configuration()); //创建文件输出流,得到默认扩展名 FileOutputStream fos = new FileOutputStream("/home/centos/zip/b" + codec.getDefaultExtension()); //得到压缩流 CompressionOutputStream zipOut = codec.createOutputStream(fos); IOUtils.copyBytes(new FileInputStream("/home/centos/zip/hadoop.txt"), zipOut, 1024); zipOut.close(); System.out.println(codecClass.getSimpleName() + " : " + (System.currentTimeMillis() - start) ); } /** * 解压缩 */ public static void unzip(Class codecClass) throws Exception { long start = System.currentTimeMillis(); //实例化对象 CompressionCodec codec = (CompressionCodec)ReflectionUtils.newInstance(codecClass, new Configuration()); //创建文件输出流,得到默认扩展名 FileInputStream fis = new FileInputStream("/home/centos/zip/b" + codec.getDefaultExtension()); //得到压缩流 CompressionInputStream zipIn = codec.createInputStream(fis); IOUtils.copyBytes(zipIn,new FileOutputStream("/home/centos/zip/hadoop" + codec.getDefaultExtension() + ".txt"), 1024); zipIn.close(); System.out.println(codecClass.getSimpleName() + " : " + (System.currentTimeMillis() - start) ); } }