来这看没错！！！报错Cannot serialize； nested exception is

model实现了Serializable 但是还是报错Cannot serialize; nested exception is

在学习Shiro使用缓存时，出现：
:异常，开启debug会提示：
ERROR [] - Disk Write of test failed: 错误。

出现这种情况是因为：SimpleByteSource没有是实现Serializable接口

解决办法：自定义一个类继承SimpleByteSource实现Serializable接口

当然也可以实现ByteSource接口和Serializable接口，但是实现ByteSource接口需要实现其方法，不方便。

自定义一个MySimpleByteSource 类继承继承SimpleByteSource实现Serializable接口
方法一：自己实现ByteSource, Serializable 的接口
在springboot启动类的同一目录下新建ShiroByteSource类

package com.englishcode.springboot_jsp_shiro;

import org.apache.shiro.codec.Base64;
import org.apache.shiro.codec.CodecSupport;
import org.apache.shiro.codec.Hex;
import org.apache.shiro.util.ByteSource;

import java.io.File;
import java.io.InputStream;
import java.io.Serializable;
import java.util.Arrays;
import java.util.Objects;

/**
 * @author cyl
 * @version 1.0
 * @date 2020/11/14 18:29
 */
public class ShiroByteSource implements ByteSource, Serializable {
    private static final long serialVersionUID = -6814382603612799610L;
    private volatile byte[] bytes;
    private String cachedHex;
    private String cachedBase64;

    public ShiroByteSource() {

    }

    public ShiroByteSource(String string) {
        this.bytes = CodecSupport.toBytes(string);
    }

    public void setBytes(byte[] bytes) {
        this.bytes = bytes;
    }

    @Override
    public byte[] getBytes() {
        return this.bytes;
    }

    @Override
    public String toHex() {
        if ( this.cachedHex == null ) {
            this.cachedHex = Hex.encodeToString(getBytes());
        }
        return this.cachedHex;
    }

    @Override
    public String toBase64() {
        if ( this.cachedBase64 == null ) {
            this.cachedBase64 = Base64.encodeToString(getBytes());
        }
        return this.cachedBase64;
    }

    @Override
    public boolean isEmpty() {
        return this.bytes == null || this.bytes.length == 0;
    }

    @Override
    public String toString() {
        return toBase64();
    }

    @Override
    public int hashCode() {
        if (this.bytes == null || this.bytes.length == 0) {
            return 0;
        }
        return Arrays.hashCode(this.bytes);
    }

    @Override
    public boolean equals(Object o) {
        if (o == this) {
            return true;
        }
        if (o instanceof ByteSource) {
            ByteSource bs = (ByteSource) o;
            return Arrays.equals(getBytes(), bs.getBytes());
        }
        return false;
    }

    public static ByteSource of(String string) {
        return new ShiroByteSource(string);
    }
}

之后在自己定义的realm中使用上边定义的类创建salt 就是盐

    //处理认证
    @Override
    protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken authenticationToken) throws AuthenticationException {
        System.out.println("调用doGetAuthenticationInfo这个函数");
        String principal = (String) authenticationToken.getPrincipal();
        //在工厂中获取service对象
        UserService userServiceImpl = (UserService) ApplicationContextUtils.getBean("userServiceImpl");
        User user = userServiceImpl.findByUserName(principal); //从数据库中查询
        if(!ObjectUtils.isEmpty(user)){
            //第三个参数注意了，随机盐应该使用ByteSource的工具类把对应的String转换为字节
            // 获取用户的盐值
            //ByteSource salt = (());  //旧代码会抛出NotSerializableException:org异常，替换成下面代码就可以了
            //最重要的是这个地方
            return new SimpleAuthenticationInfo(user.getUsername(),user.getPassword(), new ShiroByteSource(user.getSalt()),this.getName());
        }
        return null;
    }

方法二：
继承SimpleByteSource类

import ;
public class MySimpleByteSource extends
implements Serializable{
private static final long serialVersionUID = 5528101080905698238L;
public SimpleByteSource(byte[] bytes) {
super(bytes);
// TODO 自动生成的构造函数存根
}
}

自定义的realm中

return new SimpleAuthenticationInfo(userEntity, credentials,new MySimpleByteSource(userCode),getName());
但是方法二会在很多步骤中出错，只是满足了临时的不出错