后端接口返回的数据或者日志记录时，因为安全隐私的缘故难免要对字符串脱敏处理，今天利用注解写个简单的脱敏工具。

1.字符串脱敏方法

package com.util;

public class CommonUtil {
    /**
     * 
     * @param noMosaicLength 不打码字符长度，
     * @param minMosaicLength 最小打码字符长度
     * @param inputString
     * @return
     */
    public static String mosaic(int noMosaicLength,int minMosaicLength,String inputString){
        if(inputString == null || inputString.equals("")){
            return inputString;
        }
        int noMosaicPart1Length;
        int beMosaicLength = minMosaicLength;
        if(inputString.length() <= minMosaicLength){
            //保留首字符不打码
            noMosaicPart1Length = 1;
            beMosaicLength = inputString.length()-noMosaicPart1Length;
        }else{
            // 不打码长度加上最小打码长度大于输入字符串长度，则保证至少有最小打码个数字符被打码
            if(noMosaicLength+minMosaicLength >= inputString.length()){
                int singleSideNoMosaicLength = (inputString.length()-minMosaicLength)/2;
                noMosaicPart1Length=(inputString.length()-minMosaicLength)%2 == 0 ? singleSideNoMosaicLength
                :singleSideNoMosaicLength+1;
            }else{
                noMosaicPart1Length = noMosaicLength%2 == 0 ? noMosaicLength/2:noMosaicLength/2+1;
                beMosaicLength = inputString.length()-noMosaicLength;
            }
        }
        StringBuilder stringBuilder = new StringBuilder(inputString.substring(0,noMosaicPart1Length));
        for(int i=0;i<beMosaicLength;i++){
            stringBuilder.append("*");
        }
        if(noMosaicPart1Length+beMosaicLength<inputString.length()){
            stringBuilder.append(inputString.substring(noMosaicPart1Length+beMosaicLength));
        }

        return stringBuilder.toString();
    }
}

2.注解相关类

package com.annotation;

import java.lang.annotation.*;

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
@Documented
public @interface Mosaic {
    int noMosaicLength() default 0;
    MosaicType MOSAIC_TYPE() default MosaicType.INDICATE_MOSAIC_LENGTH;
    int minMosaicLength() default 3;
}

打码类型枚举类

package com.annotation;

public enum MosaicType {

    /**
     * 完全打码
     */
    FULL_MOSAIC(0),
    /**
     * 指定打码字符个数
     */
    INDICATE_MOSAIC_LENGTH(1),
    ;
    
    private  int mosaicType;
    MosaicType(int mosaicType){
        this.mosaicType = mosaicType;
    }
}

3.注解解析方法

package com.reflect;

import com.annotation.table.Mosaic;
import com.annotation.table.MosaicType;
import com.ly.entity.Student;
import com.util.CommonUtil;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;

public class MosaicUtil {

	public static  <T> T getMosaicObj(Object obj,Class<T> tClass) throws IllegalAccessException {
		Class<?> objClazz = obj.getClass();
		Field[] fields = objClazz.getDeclaredFields();
		for(Field field:fields){
			field.setAccessible(true);
			Mosaic mosaic = field.getAnnotation(Mosaic.class);
			Object object = field.get(obj);
			if(mosaic != null && object != null){
				if(object.getClass().isAssignableFrom(String.class)){
					Object mosaicString = mosaicString((String)object,mosaic);
					field.set(obj, mosaicString);
				}

			}
		}
		return (T) obj;
	}

	public static Object mosaicString(String src,Mosaic mosaic){
		String des= "";
		if(mosaic.MOSAIC_TYPE().equals(MosaicType.FULL_MOSAIC)){
			des = CommonUtil.mosaic(0,src.length()-1,src);

		}else if(mosaic.MOSAIC_TYPE().equals(MosaicType.FULL_MOSAIC)){
			des= CommonUtil.mosaic(mosaic.noMosaicLength(),mosaic.minMosaicLength(),
					src);
		}
		return des;
	}
}

4.用法

package com.ly.entity;

import com.annotation.table.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

public class Student implements Serializable{
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	@Mosaic(noMosaicLength = 2,minMosaicLength = 3,MOSAIC_TYPE = MosaicType.FULL_MOSAIC)
	private String name;
	private int age;
	private Teacher t;
	
	public Student() {
		super();
	}

	public Student(String name,int age) {
		super();
		this.name = name;
		this.age = age;
	}

	public Student(String string, Object object) {
		// TODO Auto-generated constructor stub
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public Teacher getT() {
		return t;
	}

	public void setT(Teacher t) {
		this.t = t;
	}

	
	
	
	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	
	@Override
	public String toString() {
		return "Student [name=" + name + ", age=" + age + ", t=" + t + "]";
	}

	public static void main(String[] args){
		
		Student student = new Student();
		student.setName("qwerty123");
		System.out.println(MosaicUtil.getMosaicObj(student,Student.class));
	}

}