接口KeyGenerator

image.png

要實現自定義，要實現spring提供的接口KeyGenerator
package org.springframework.cache.interceptor;

helper

• fastjson

public class JsonHelper {


    /**
     * Java對象序列化為JSON字符串
     *
     * @param obj Java對象
     * @return json字符串
     */
    public static String toJson(Object obj) {
        return JSON.toJSONString(obj, SerializerFeature.WriteMapNullValue);
    }
}

• beanHelper

package com.ghgcn.mysb.chapter03.helper;

import org.springframework.util.ClassUtils;

import java.net.URI;
import java.net.URL;
import java.util.Date;
import java.util.Locale;

public class BeanHelper {
    /**
     * 判斷是否是簡單值類型.包括：基礎數據類型块饺、CharSequence洞拨、Number欣范、Date沽损、URL巾表、URI袖外、Locale史隆、Class;
     *
     * @param clazz
     * @return
     */
    public static boolean isSimpleValueType(Class<?> clazz) {
        return (ClassUtils.isPrimitiveOrWrapper(clazz) || clazz.isEnum() || CharSequence.class.isAssignableFrom(clazz)
                || Number.class.isAssignableFrom(clazz) || Date.class.isAssignableFrom(clazz) || URI.class == clazz
                || URL.class == clazz || Locale.class == clazz || Class.class == clazz);
    }
}

SpringCacheKeyGenerator

package com.ghgcn.mysb.chapter03.support;

import com.ghgcn.mysb.chapter03.helper.BeanHelper;
import com.ghgcn.mysb.chapter03.helper.JsonHelper;
import org.springframework.cache.interceptor.KeyGenerator;

import java.lang.reflect.Method;
@Component //標記為組件
public class SpringCacheKeyGenerator implements KeyGenerator {

    private final static int NO_PARAM_KEY = 0;
    private String keyPrefix = "jf";// key前綴，用于區(qū)分不同項目的緩存曼验，建議每個項目單獨設置



    @Override
    public Object generate(Object target, Method method, Object... params) {

        char sp = ':';
        StringBuilder strBuilder = new StringBuilder(30);
        strBuilder.append(keyPrefix);
        strBuilder.append(sp);
        // 類名
        strBuilder.append(target.getClass().getSimpleName());
        strBuilder.append(sp);
        // 方法名
        strBuilder.append(method.getName());
        strBuilder.append(sp);
        if (params.length > 0) {
            // 參數值
            for (Object object : params) {
                if (BeanHelper.isSimpleValueType(object.getClass())) {
                    strBuilder.append(object);
                } else {
                    strBuilder.append(JsonHelper.toJson(object).hashCode());
                }
            }
        } else {
            strBuilder.append(NO_PARAM_KEY);
        }
        return strBuilder.toString();
    }



    public String getKeyPrefix() {
        return keyPrefix;
    }

    public void setKeyPrefix(String keyPrefix) {
        this.keyPrefix = keyPrefix;
    }
}