Java通过StringUtils实现补全、截取字符串

1、添加依赖

<dependency>
	<groupId>org.apache.commons</groupId>
	<artifactId>commons-lang3</artifactId>
	<version>3.4</version>
</dependency>

2、工具测试类

package com.shucha.deveiface.biz.test;

import org.apache.commons.lang3.StringUtils;

import java.io.UnsupportedEncodingException;

/**
 * @author tqf
 * @Description 字符串补全、截取
 * @Version 1.0
 * @since 2022-07-15 09:47
 */
public class Completion {
    public static void main(String[] args) {
        // 2个字符串补全长度一样
        lengthStr("2587发","192.168.0.125"," ");

        String str = "字符串补全和截取的方法测试";
        System.out.println("左侧补全：" + completionStr(str,18, "*",0,0));
        System.out.println("中间补全：" + completionStr(str,18, "*",0,1));
        System.out.println("右边补全：" + completionStr(str,18, "*",0,2));
        System.out.println("左侧截取：" + completionStr(str,2, "*",1,0));
        System.out.println("中间截取：" + completionStr(str,5, "*",1,1));
        System.out.println("右边截取：" + completionStr(str,6, "*",1,2));
        System.out.println("手机号脱敏：" + wordMask("12365485744",3,4,"*"));
        System.out.println("身份证号码脱敏：" + wordMask("340604199908022750",4,4,"*"));
    }

    /**
     * 2个字符串比较长度 添加字符补全一样的长度
     * @param oneStr 第一个字符串
     * @param twoStr 第二个字符串
     * @param padStr 补全的字符
     */
    public static void lengthStr(String oneStr, String twoStr, String padStr){
        try {
            int beforeLength = oneStr.getBytes("gbk").length;
            int afterLength = twoStr.getBytes("gbk").length;
            int gapSize = beforeLength - afterLength;
            if (gapSize > 0) {
                twoStr = StringUtils.rightPad(twoStr, gapSize + twoStr.length(), padStr);
            }
            if (gapSize < 0) {
                oneStr = StringUtils.rightPad(oneStr, Math.abs(gapSize) + oneStr.length(), padStr);
            }
            System.out.println(oneStr);
            System.out.println(twoStr);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }

    /**
     * 字符串-补全、截取
     * @param string 原始字符串
     * @param length 字补全后的符串长度
     * @param padStr 补充的字符串
     * @param type    类型 0-补全字符串,1-截取字符串
     * @param padType 补全的方式 0-左侧补齐，1-中间补齐,2-右侧补齐
     * @return
     */
    public static String completionStr(String string, int length, String padStr, int type, int padType){
        String str = "";
        if(type == 0){
            switch (padType) {
                case 0:
                    str = StringUtils.leftPad(string, length, padStr);
                    break;
                case 1:
                    str = StringUtils.center(string, length, padStr);
                    break;
                case 2:
                    str = StringUtils.rightPad(string, length, padStr);
                    break;
                default:
                    str = "";
            }
        } else {
            switch (padType) {
                case 0:
                    str = StringUtils.left(string, length);
                    break;
                case 1:
                    str = StringUtils.center(string, length);
                    break;
                case 2:
                    str = StringUtils.right(string, length);
                    break;
                default:
                    str = "";
            }
        }
        return str;
    }

    /**
     * 对字符串进行脱敏处理
     * @param word        被脱敏的字符
     * @param startLength 被保留的开始长度 前余n位
     * @param endLength   被保留的结束长度 后余n位
     * @param pad         填充字符
     */
    public static String wordMask(String word, int startLength, int endLength, String pad) {
        if (StringUtils.isAnyBlank(word, pad)) {
            return word;
        }
        if (startLength + endLength > word.length()) {
            return StringUtils.leftPad("", word.length() - 1, pad);
        }
        String startStr = word.substring(0, startLength);
        String endStr = word.substring(word.length() - endLength, word.length());
        return startStr + StringUtils.leftPad("", word.length() - startLength - endLength, pad) + endStr;

    }
}

3、测试结果如图