欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  IT编程

Spring Utils工具类常用方法实例

程序员文章站 2022-04-05 23:02:29
spring提供的工具类,主要用于框架内部使用,这个类提供了一些简单的方法,并且提供了易于使用的方法在分割字符串,如csv字符串,以及集合和数组。stringutils提供常用的方法如下:判断对象对象...

spring提供的工具类,主要用于框架内部使用,这个类提供了一些简单的方法,并且提供了易于使用的方法在分割字符串,如csv字符串,以及集合和数组。

stringutils提供常用的方法如下:

判断对象对象是否为null或者空字符串

public static boolean isempty(@nullable object str) {
	return (str == null || "".equals(str));
}

判断给的序列是否为空或者length为0

public static boolean haslength(@nullable charsequence str) {
	return (str != null && str.length() > 0);
}

	public static boolean haslength(@nullable string str) {
		return (str != null && !str.isempty());
	}

判断字符串是否以某个字符串开头

public static boolean startswithignorecase(@nullable string str, @nullable string prefix) {
	return (str != null && prefix != null && str.length() >= prefix.length() &&
			str.regionmatches(true, 0, prefix, 0, prefix.length()));
}

判断字符串是否以某个字符串结尾

public static boolean endswithignorecase(@nullable string str, @nullable string suffix) {
	return (str != null && suffix != null && str.length() >= suffix.length() &&
			str.regionmatches(true, str.length() - suffix.length(), suffix, 0, suffix.length()));
}

用另一个字符串替换字符串中出现的所有子字符串

public static string replace(string instring, string oldpattern, @nullable string newpattern) {
		if (!haslength(instring) || !haslength(oldpattern) || newpattern == null) {
			return instring;
		}
		//oldpattern字符串第一次出现的位置
		int index = instring.indexof(oldpattern);
		if (index == -1) {
			// no occurrence -> can return input as-is
			return instring;
		}
		//字符串长度
	int capacity = instring.length();
	if (newpattern.length() > oldpattern.length()) {
		capacity += 16;
	}
	stringbuilder sb = new stringbuilder(capacity);

	int pos = 0; // our position in the old string
	int patlen = oldpattern.length();
	while (index >= 0) {
		sb.append(instring, pos, index);
		sb.append(newpattern);
		pos = index + patlen;
		index = instring.indexof(oldpattern, pos);
	}

	// append any characters to the right of a match
	sb.append(instring, pos, instring.length());
	return sb.tostring();
}

根据给定的路径规范化路径

public static string cleanpath(string path) {
		if (!haslength(path)) {
			return path;
		}
  //用新字符串替换旧字符串
	string pathtouse = replace(path, windows_folder_separator, folder_separator);
	// shortcut if there is no work to do
	if (pathtouse.indexof('.') == -1) {
		return pathtouse;
	}

	// strip prefix from path to analyze, to not treat it as part of the
	// first path element. this is necessary to correctly parse paths like
	// "file:core/../core/io/resource.class", where the ".." should just
	// strip the first "core" directory while keeping the "file:" prefix.
	int prefixindex = pathtouse.indexof(':');
	string prefix = "";
	if (prefixindex != -1) {
		prefix = pathtouse.substring(0, prefixindex + 1);
		if (prefix.contains(folder_separator)) {
			prefix = "";
		}
		else {
			pathtouse = pathtouse.substring(prefixindex + 1);
		}
	}
	if (pathtouse.startswith(folder_separator)) {
		prefix = prefix + folder_separator;
		pathtouse = pathtouse.substring(1);
	}

	string[] patharray = delimitedlisttostringarray(pathtouse, folder_separator);
	linkedlist<string> pathelements = new linkedlist<>();
	int tops = 0;

	for (int i = patharray.length - 1; i >= 0; i--) {
		string element = patharray[i];
		if (current_path.equals(element)) {
			// points to current directory - drop it.
		}
		else if (top_path.equals(element)) {
			// registering top path found.
			tops++;
		}
		else {
			if (tops > 0) {
				// merging path element with element corresponding to top path.
				tops--;
			}
			else {
				// normal path element found.
				pathelements.add(0, element);
			}
		}
	}

	// remaining top paths need to be retained.
	for (int i = 0; i < tops; i++) {
		pathelements.add(0, top_path);
	}
	// if nothing else left, at least explicitly point to current path.
	if (pathelements.size() == 1 && "".equals(pathelements.getlast()) && !prefix.endswith(folder_separator)) {
		pathelements.add(0, current_path);
	}

	return prefix + collectiontodelimitedstring(pathelements, folder_separator);
}

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。