代码如下：
1 package my;
2
3 import java.io.BufferedInputStream;
4 import java.io.BufferedOutputStream;
5 import java.io.BufferedReader;
6 import java.io.BufferedWriter;
7 import java.io.File;
8 import java.io.FileInputStream;
9 import java.io.FileOutputStream;
10 import java.io.FileReader;
11 import java.io.FileWriter;
12 import java.io.RandomAccessFile;
13 import java.io.Reader;
14 import java.io.Writer;
15 import java.nio.ByteBuffer;
16 import java.nio.channels.FileChannel;
17
18 /**
19 * 文件拷贝各种方式的比较
20 *
21 */
22 public class TestFile {
23
24 public final static String FILE_PATH ="D:\\电影\\[电影天堂www.dy2018.com]特殊身份BD中英双字.mkv";
25
26 //public final static String FILE_PATH = "F:\\apache-tomcat-7.0.11\\webapps\\ROOT\\a.rar";
27
28 public final static String FILE_PATH_OUT = "D:\\哈哈.mkv";
29
30 public static void TransByCommonIoStream() throws Exception {
31
32 long beginTime = System.currentTimeMillis();
33
34 FileInputStream fis = new FileInputStream(new File(FILE_PATH));
35
36 FileOutputStream fos = new FileOutputStream(new File(FILE_PATH_OUT));
37
38 byte[] b = new byte[1024];
39
40 int len = 0;
41
42 while ((len = fis.read(b)) != -1) {
43 fos.write(b, 0, len);
44 }
45
46 fos.flush();
47
48 fis.close();
49 fos.close();
50
51 long endTime = System.currentTimeMillis();
52
53 System.out.println("采用传统IO FileInputStream 读取，耗时："
54 + (endTime - beginTime));
55
56 }
57
58 public static void TransByCommonIoBufferedStream() throws Exception {
59
60 long beginTime = System.currentTimeMillis();
61
62 FileInputStream fis = new FileInputStream(new File(FILE_PATH));
63
64 FileOutputStream fos = new FileOutputStream(new File(FILE_PATH_OUT));
65
66 BufferedInputStream bis = new BufferedInputStream(fis);
67
68 BufferedOutputStream bos = new BufferedOutputStream(fos);
69
70 byte[] b = new byte[1024];
71
72 int len = 0;
73
74 while ((len = bis.read(b)) != -1) {
75 bos.write(b, 0, len);
76 }
77
78 bos.flush();
79
80 fis.close();
81 fos.close();
82 bis.close();
83 bos.close();
84
85 long endTime = System.currentTimeMillis();
86
87 System.out.println("采用传统IO BufferedInputStream 读取，耗时："
88 + (endTime - beginTime));
89
90 }
91
92 public static void TransByCommonIoBuffered() throws Exception {
93
94 long beginTime = System.currentTimeMillis();
95
96 Reader br = new BufferedReader(new FileReader(new File(FILE_PATH)));
97 Writer bw = new BufferedWriter(new FileWriter(new File(FILE_PATH_OUT)));
98
99 char[] c = new char[1024];
100
101 int len = 0;
102
103 while ((len = br.read(c)) != -1) {
104 bw.write(c, 0, len);
105 }
106
107 bw.flush();
108 br.close();
109 bw.close();
110
111 long endTime = System.currentTimeMillis();
112
113 System.out.println("采用传统IO BufferedReader 读取，耗时："
114 + (endTime - beginTime));
115 }
116
117 public static void TransByRandomAccFile() throws Exception {
118
119 long beginTime = System.currentTimeMillis();
120
121 FileInputStream fis = new FileInputStream(new File(FILE_PATH));
122
123 RandomAccessFile raf = new RandomAccessFile(new File(FILE_PATH_OUT),
124 "rw");
125
126 byte[] b = new byte[1024];
127
128 int len = 0;
129
130 while ((len = fis.read(b)) != -1) {
131 raf.write(b, 0, len);
132 }
133
134 long endTime = System.currentTimeMillis();
135
136 System.out.println("采用传统IO RandomAccessFile 读取，耗时："
137 + (endTime - beginTime));
138
139 }
140
141 /**
142 * 采用FileChannel 自带方法测试 public abstract long
143 * transferFrom(ReadableByteChannel src, long position, long count) throws
144 * IOException;
145 */
146 public static void TransByNioFileChannel() throws Exception {
147
148 long beginTime = System.currentTimeMillis();
149
150 FileChannel fc = new FileInputStream(new File(FILE_PATH)).getChannel();
151
152 // FileChannel fco = new RandomAccessFile(new File(FILE_PATH_OUT), "rw").getChannel();
153 FileChannel fco = new FileOutputStream(new File(FILE_PATH_OUT)).getChannel();
154
155 fco.transferFrom(fc, 0, fc.size());
156
157 long endTime = System.currentTimeMillis();
158
159 System.out.println("采用NIO FileChannel 自带方法 读取，耗时："
160 + (endTime - beginTime));
161 }
162
163 public static void TransByNioFileChannelCommon() throws Exception {
164
165 long beginTime = System.currentTimeMillis();
166
167 FileChannel fc = new FileInputStream(new File(FILE_PATH)).getChannel();
168
169 FileChannel fco = new RandomAccessFile(new File(FILE_PATH_OUT), "rw")
170 .getChannel();
171
172 ByteBuffer buf = ByteBuffer.allocate(1024);
173
174 while (fc.read(buf) != -1) {
175 buf.flip();
176 fco.write(buf);
177 buf.clear();
178 }
179
180 long endTime = System.currentTimeMillis();
181
182 System.out.println("采用NIO FileChannel 循环 读取，耗时："
183 + (endTime - beginTime));
184 }
185
186 public static void deleteFile() {
187 File f = new File(FILE_PATH_OUT);
188 if (f.exists())
189 f.delete();
190 }
191
192 public static void main(String[] args) throws Exception {
193
194 TransByCommonIoStream();
195 deleteFile();
196 TransByCommonIoBufferedStream();
197 deleteFile();
198 TransByRandomAccFile();
199 deleteFile();
200 TransByNioFileChannel();
201 deleteFile();
202 TransByNioFileChannelCommon();
203 deleteFile();
204 }
205 }
测试结果：
1 采用传统IO FileInputStream 读取，耗时：11393 2 采用传统IO BufferedInputStream 读取，耗时：1191 3 采用传统IO RandomAccessFile 读取，耗时：2929 4 采用NIO FileChannel 自带方法 读取，耗时：485 5 采用NIO FileChannel 循环 读取，耗时：2502
时间： 2024-10-25 13:51:34