1.深入分析_NIO性能分析

  1 package com.ctyun.stream;
  2 
  3 import java.io.BufferedInputStream;
  4 import java.io.BufferedOutputStream;
  5 import java.io.File;
  6 import java.io.FileInputStream;
  7 import java.io.FileNotFoundException;
  8 import java.io.FileOutputStream;
  9 import java.io.IOException;
 10 import java.nio.channels.FileChannel;
 11 /**
 12  * 
 13  * @Description    文件效率copy测试
 14  * @author         zhanghw@chinatelecom.com.cn
 15  * @since          2015年9月11日
 16  * @version        V1.0
 17  */
 18 public class FileCopyEfficientTest {
 19     
 20     //普通io流copy
 21     public static void commonCopy(String source, String dest){
 22         FileInputStream in = null;
 23         FileOutputStream out = null;
 24         try {
 25             in = new FileInputStream(new File(source));
 26             out = new FileOutputStream(new File(dest));
 27             
 28             byte[] b = new byte[2048];
 29             while(in.read(b) != -1  ){
 30                 out.write(b);
 31             }
 32             out.flush();
 33             
 34         } catch (FileNotFoundException e) {
 35             e.printStackTrace();
 36         } catch (IOException e) {
 37             // TODO Auto-generated catch block
 38             e.printStackTrace();
 39         }finally{
 40             try {
 41                 if(in != null){
 42                     in.close();
 43                 }
 44                 if(out != null){
 45                     out.close();
 46                 }
 47             } catch (IOException e) {
 48                 // TODO Auto-generated catch block
 49                 in = null;
 50                 out =null;
 51                 e.printStackTrace();
 52             }
 53         }
 54     }
 55     
 56     //Streambuffer进行copy
 57     public static void bufferCopy(String source, String dest){
 58         FileInputStream in = null;
 59         FileOutputStream out = null;
 60         BufferedInputStream bufferedIn = null;
 61         BufferedOutputStream bufferedOut = null;
 62         
 63         try {
 64             in = new FileInputStream(new File(source));
 65             out = new FileOutputStream(new File(dest));
 66             
 67             bufferedIn = new BufferedInputStream(in);
 68             bufferedOut = new BufferedOutputStream(out);
 69             
 70             byte[] b = new byte[2048];
 71             while(bufferedIn.read(b) != -1  ){
 72                 bufferedOut.write(b);
 73             }
 74             bufferedOut.flush();
 75             
 76         } catch (FileNotFoundException e) {
 77             e.printStackTrace();
 78         } catch (IOException e) {
 79             // TODO Auto-generated catch block
 80             e.printStackTrace();
 81         }finally{
 82             try {
 83                 if(in != null){
 84                     in.close();
 85                 }
 86                 if(out != null){
 87                     out.close();
 88                 }
 89                 if(bufferedIn != null){
 90                     bufferedIn.close();
 91                 }
 92                 if(bufferedOut != null){
 93                     bufferedOut.close();
 94                 }
 95             } catch (IOException e) {
 96                 // TODO Auto-generated catch block
 97                 in = null;
 98                 out =null;
 99                 bufferedIn = null;
100                 bufferedOut = null;
101                 e.printStackTrace();
102             }
103         }
104     }
105     
106     //用Channel进行copy
107     public static void channelCopy(String source, String dest){
108         FileInputStream in = null;
109         FileOutputStream out = null;
110         FileChannel channelIn = null;
111         FileChannel channelOut = null;
112         
113         try {
114             in = new FileInputStream(new File(source));
115             out = new FileOutputStream(new File(dest));
116             channelIn = in.getChannel();
117             channelOut = out.getChannel();
118             
119             channelIn.transferTo(0, channelIn.size(), channelOut);
120             
121         } catch (FileNotFoundException e) {
122             e.printStackTrace();
123         } catch (IOException e) {
124             // TODO Auto-generated catch block
125             e.printStackTrace();
126         }finally{
127             try {
128                 if(in != null){
129                     in.close();
130                 }
131                 if(out != null){
132                     out.close();
133                 }
134                 if(channelIn != null){
135                     channelIn.close();
136                 }
137                 if(channelOut != null){
138                     channelOut.close();
139                 }
140                 
141             } catch (IOException e) {
142                 // TODO Auto-generated catch block
143                 in = null;
144                 out =null;
145                 channelIn = null;
146                 channelOut = null;
147                 e.printStackTrace();
148             }
149         }
150         
151     }
152     
153     //测试因为会线程原因，造成时间不正确
154     /*public static void main(String[] args) {
155         String source = "d:/test.txt";
156         String dest1 = "d:/temp/test1.txt";
157         String dest2 = "d:/temp/test2.txt";
158         String dest3 = "d:/temp/test3.txt";
159         
160         long l1 = System.currentTimeMillis();
161         commonCopy(source, dest1);
162         long l2 = System.currentTimeMillis();
163         System.out.println("普通Stream Copy用时："+(l2-l1));
164         
165         bufferCopy(source, dest2);
166         long l3 = System.currentTimeMillis();
167         System.out.println("buffer Stream Copy用时："+(l3-l2));
168         
169         channelCopy(source, dest3);
170         long l4 = System.currentTimeMillis();
171         System.out.println("channel Stream Copy用时："+(l4-l3));
172         
173     }*/
174     
175     public static void main(String[] args) {
176         String source = "d:/test.txt";
177         String dest = "d:/temp/test1.txt";
178         
179         long l1 = System.currentTimeMillis();
180 //        commonCopy(source, dest);
181         bufferCopy(source, dest);
182 //        channelCopy(source, dest);
183         long l2 = System.currentTimeMillis();
184         System.out.println("Copy用时："+(l2-l1));
185         
186     }
187 
188 }