package org.maoge.thread;
import java.io.File;
/**
 * 读取文件大小
 */
public class ReadFileRunnable implements Runnable {
  private String fileName;
  public ReadFileRunnable(String fileName) {
    this.fileName = fileName;
  }
  @Override
  public void run() {
    File f = new File(fileName);
    if (f.exists() && f.isFile()) {
      System.out.println("[" + fileName + "] length:" + f.length());
    } else {
      System.out.println("[" + fileName + "] not exists");
    }
  }
}
3. 测试
编写测试类：
package org.maoge.thread;
/**
 * 读文件测试
 */
public class ReadFileTest {
  public static void main(String[] args) {
    for (int i = 0; i < 10; i++) {
      ReadFileRunnable writeFile = new ReadFileRunnable("D:\\temp\\" + (i + 500) + ".txt");
      Thread thread = new Thread(writeFile);
      thread.start();
    }
  }
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
4. 结果
因为我们之前通过Java 继承Thread实现线程写了10个文件，所以此处直接输出结果：
[D:\temp\500.txt] length:1000000
[D:\temp\501.txt] length:1000000
[D:\temp\504.txt] length:1000000
[D:\temp\508.txt] length:1000000
[D:\temp\503.txt] length:1000000
[D:\temp\505.txt] length:1000000
[D:\temp\506.txt] length:1000000
[D:\temp\509.txt] length:1000000
[D:\temp\502.txt] length:1000000
[D:\temp\507.txt] length:1000000