import java.util.Random;
public class Random_str {
	public static String RandomJianHan(int len) {
		String ret = "";
		for (int i = 0; i < len; i++) {
			String str = null;
			int hightPos, lowPos; // 定义高低位
			Random random = new Random();
			hightPos = (176 + Math.abs(random.nextInt(39))); // 获取高位值
			lowPos = (161 + Math.abs(random.nextInt(93))); // 获取低位值
			byte[] b = new byte[2];
			b[0] = (new Integer(hightPos).byteValue());
			b[1] = (new Integer(lowPos).byteValue());
			try {
				str = new String(b, "GBK"); // 转成中文
			} catch(UnsupportedEncodingException ex) {
				ex.printStackTrace();
			}
			ret += str;
		}

		return ret;
	}
}

Random_str ran = new Random_str();
String content = ran.RandomJianHan(30); //此处生成的是长度为4的字符串
vars.put("Content",content);

String content1 = "接口自动化发布帖子，这是随机内容："+ran.RandomJianHan(4);//此处生成的是长度为4的字符串
vars.put("content_post",content1);
String content2 = "接口自动化评论帖子，这是随机评论内容："+ran.RandomJianHan(4);
vars.put("content_comment",content2);
String content3 = "接口自动化回复评论，这是随机回复内容："+ran.RandomJianHan(4);
vars.put("content_reply",content3);