生成随机字符串

org.apache.commons.lang.RandomStringUtils.random(20, "abcdefghijklmnopqrstuvwxyz1234567890");

 

20是字符串长度，后面一个字符串参数，是随机字符串中可能出现的字符组成。

下面是一个批量生成文件的范例，文件内容为随机字符串，文件名和大小通过数组指定。

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

import org.apache.commons.lang.RandomStringUtils;

public class DummyFileHelper {
	private final static String RAMDOM_SOURCE = "abcdefghijklmnopqrstuvwxyz1234567890";
	private final static String BASE_FOLDER = "D:\\temp";

	public static void main(String[] args) throws IOException {
		String filenamePrefix = "test";
		String filenamePostfix = ".data";
		String[] filenameArray = new String[] { "1K", "10K", "500K", "1M",
				"10M", "100M" };
		int[] fileLengthArray = new int[] { 1, 10, 500, 1024, 1024 * 10,
				1024 * 100 };
		for (int j = 0; j < fileLengthArray.length; j++) {
			String filename = BASE_FOLDER + File.separator + filenamePrefix
					+ '_' + filenameArray[j] + filenamePostfix;
			FileWriter writer = new FileWriter(filename);
			for (int i = 0; i < fileLengthArray[j]; i++) {
				writer.write(RandomStringUtils.random(1024, RAMDOM_SOURCE));
			}
			writer.close();
			System.out.println(filename + "文件生成完毕。");
		}
	}

}