自定义注解结合Aop数据字典应用
本篇博客主要聊聊自定义注解在项目中的应用，自定义注解用来做系统监控日志，这个用法已经烂大街了，无法让面试官眼前一亮的感觉。
项目开发中数据字典使用场景非常多，使用数据字典有一点非常的不方便，那就是数据库中存放的是数字，而实际页面上展示的却是汉字；那么这也就造成了，每次做页面展示的时候都需要给数字进行转义，将其转义成汉字内容展示到页面，而转换的过程过于繁琐；
咱们的自定义注解可以完美的解决这一问题；
浏览器输入：http://localhost:8080/student/listPager 测试
最后浏览器访问的效果图
当然，也可以不走默认规则，xxx就是在类属性上的自定义注解的属性值
相关的pom依赖
<dependency>
<groupId>com.alibabagroupId>
<artifactId>fastjsonartifactId>
<version>1.2.4version>
dependency>
逆向工程生成实体类、mapper.xml、mapper.java
实体类
package com.zhou.model;
public class DataDict {
private Integer id;
private String datasource;
private String description;
public DataDict(Integer id, String datasource, String description) {
this.id = id;
this.datasource = datasource;
this.description = description;
}
public DataDict() {
super();
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getDatasource() {
return datasource;
}
public void setDatasource(String datasource) {
this.datasource = datasource;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
package com.zhou.model;
public class DataItem {
private Integer id;
private String datasource;
private String code;
private String val;
public DataItem(Integer id, String datasource, String code, String val) {
this.id = id;
this.datasource = datasource;
this.code = code;
this.val = val;
}
public DataItem() {
super();
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getDatasource() {
return datasource;
}
public void setDatasource(String datasource) {
this.datasource = datasource;
}
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
public String getVal() {
return val;
}
public void setVal(String val) {
this.val = val;
}
}
package com.zhou.model;
import com.zhou.annotation.Dict;
public class Student {
private Integer id;
private String name;
@Dict(dicDataSource = "stu_Level")
private Integer stulevel;
@Dict(dicDataSource = "stu_English",dicText = "xxx")
private Integer englishlevel;
@Dict(dicDataSource = "stu_hobby")
private String stuhobby;
public Student(Integer id, String name, Integer stulevel, Integer englishlevel, String stuhobby) {
this.id = id;
this.name = name;
this.stulevel = stulevel;
this.englishlevel = englishlevel;
this.stuhobby = stuhobby;
}
public Student() {
super();
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getStulevel() {
return stulevel;
}
public void setStulevel(Integer stulevel) {
this.stulevel = stulevel;
}
public Integer getEnglishlevel() {
return englishlevel;
}
public void setEnglishlevel(Integer englishlevel) {
this.englishlevel = englishlevel;
}
public String getStuhobby() {
return stuhobby;
}
public void setStuhobby(String stuhobby) {
this.stuhobby = stuhobby;
}
}
Mapper.java
package com.zhou.mapper;
import com.zhou.model.DataDict;
public interface DataDictMapper {
int deleteByPrimaryKey(Integer id);
int insert(DataDict record);
int insertSelective(DataDict record);
DataDict selectByPrimaryKey(Integer id);
int updateByPrimaryKeySelective(DataDict record);
int updateByPrimaryKey(DataDict record);
}
package com.zhou.mapper;
import com.zhou.model.DataItem;
import org.springframework.stereotype.Repository;
import org.springframework.web.bind.annotation.ResponseBody;
@Repository
public interface DataItemMapper {
int deleteByPrimaryKey(Integer id);
int insert(DataItem record);
int insertSelective(DataItem record);
DataItem selectByPrimaryKey(Integer id);
int updateByPrimaryKeySelective(DataItem record);
int updateByPrimaryKey(DataItem record);
DataItem selectByDatasourceCode(DataItem dataItem);
}
package com.zhou.mapper;
import com.zhou.model.Student;
import org.springframework.stereotype.Repository;
import java.util.List;
@Repository
public interface StudentMapper {
int deleteByPrimaryKey(Integer id);
int insert(Student record);
int insertSelective(Student record);
Student selectByPrimaryKey(Integer id);
int updateByPrimaryKeySelective(Student record);
int updateByPrimaryKey(Student record);
List<Student> listPager(Student student);
}
Service层
package com.zhou.service;
import com.zhou.model.DataItem;
public interface DataItemService {
DataItem selectByDatasourceKey(DataItem dataItem);
String selectByDatasourceKey(String dataSource, String key);
}
package com.zhou.service;
import com.zhou.model.Student;
import com.zhou.util.PageBean;
import java.util.List;
public interface StudentService {
List<Student> listPager(Student student, PageBean pageBean);
}
package com.zhou.service.impl;
import com.zhou.mapper.DataItemMapper;
import com.zhou.model.DataItem;
import com.zhou.service.DataItemService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
@Service
public class DataItemServiceImpl implements DataItemService {
@Autowired
private DataItemMapper dataItemMapper;
@Override
public DataItem selectByDatasourceKey(DataItem dataItem) {
return dataItemMapper.selectByDatasourceCode(dataItem);
}
@Override
public String selectByDatasourceKey(String dataSource, String key) {
DataItem dataItem = new DataItem();
dataItem.setDatasource(dataSource);
dataItem.setCode(key);
return dataItemMapper.selectByDatasourceCode(dataItem).getVal();
}
}
package com.zhou.service.impl;
import com.zhou.mapper.StudentMapper;
import com.zhou.model.Student;
import com.zhou.service.StudentService;
import com.zhou.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class StudentServiceImpl implements StudentService {
@Autowired
private StudentMapper studentMapper;
@Override
public List<Student> listPager(Student student, PageBean pageBean) {
return studentMapper.listPager(student);
}
}
重点代码来了
package com.zhou.controller;
import com.zhou.model.Student;
import com.zhou.service.StudentService;
import com.zhou.util.PageBean;
import com.zhou.util.PageUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import javax.servlet.http.HttpServletRequest;
import java.util.List;
@Controller
@RequestMapping("/student")
public class StudentController {
@Autowired
private StudentService studentService;
@ResponseBody
@RequestMapping("/listPager")
public PageUtils listPager(Student student, HttpServletRequest req){
PageBean pageBean = new PageBean();
pageBean.setRequest(req);
List<Student> list = this.studentService.listPager(student,pageBean);
PageUtils pageUtils = new PageUtils(list,pageBean.getTotal());
return pageUtils;
}
}
DictAspect.java
package com.zhou.aspect;
import com.alibaba.fastjson.JSONObject;
import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.zhou.annotation.Dict;
import com.zhou.service.DataItemService;
import com.zhou.util.ObjConvertUtils;
import com.zhou.util.PageUtils;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import java.lang.reflect.Field;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
@Aspect
@Component
@Slf4j
public class DictAspect {
private static String DICT_TEXT_SUFFIX = "_dictText";
@Autowired
private DataItemService dataItemService;
// 定义切点Pointcut 拦截所有对服务器的请求
@Pointcut("execution( * com.zhou.controller.*.*(..))")
public void excudeService() {
}
/**
* 这是触发 excudeService 的时候会执行的，在环绕通知中目标对象方法被调用后的结果进行再处理
*
* @param pjp
* @return
* @throws Throwable
*/
@Around("excudeService()")
public Object doAround(ProceedingJoinPoint pjp) throws Throwable {
//这是定义开始事件
long time1 = System.currentTimeMillis();
//这是方法并获取返回结果
Object result = pjp.proceed();
//这是获取到 结束时间
long time2 = System.currentTimeMillis();
log.debug("获取JSON数据 耗时：" + (time2 - time1) + "ms");
//解析开始时间
long start = System.currentTimeMillis();
//开始解析（翻译字段内部的值凡是打了 @Dict 这玩意的都会被翻译）
this.parseDictText(result);
//解析结束时间
long end = System.currentTimeMillis();
log.debug("解析注入JSON数据 耗时" + (end - start) + "ms");
return result;
}
/**
* 本方法针对返回对象为Result 的PageUtils的分页列表数据进行动态字典注入
* 字典注入实现 通过对实体类添加注解@dict 来标识需要的字典内容,字典分为单字典dataSource即可
* 示例为Student
* 字段为stu_sex 添加了注解@Dict(dicDataSource = "stu_sex") 会在字典服务立马查出来对应的text 然后在请求list的时候将这个字典text，已字段名称加_dictText形式返回到前端
* 例输入当前返回值的就会多出一个stu_sex_dictText字段
* {
* stu_sex:1,
* stu_sex_dictText:"男"
* }
* 前端直接取值sext_dictText在table里面无需再进行前端的字典转换了
* customRender:function (text) {
* if(text==1){
* return "男";
* }else if(text==2){
* return "女";
* }else{
* return text;
* }
* }
* 目前vue是这么进行字典渲染到table上的多了就很麻烦了 这个直接在服务端渲染完成前端可以直接用
*
* @param result
*/
private void parseDictText(Object result) {
if (result instanceof PageUtils) {
List<JSONObject> items = new ArrayList<>();
PageUtils pageUtils = (PageUtils) result;
//循环查找出来的数据
for (Object record : pageUtils.getData()) {
ObjectMapper mapper = new ObjectMapper();
String json = "{}";
try {
//解决@JsonFormat注解解析不了的问题详见SysAnnouncement类的@JsonFormat
json = mapper.writeValueAsString(record);
} catch (JsonProcessingException e) {
log.error("json解析失败" + e.getMessage(), e);
}
JSONObject item = JSONObject.parseObject(json);
//update-begin--Author:scott -- Date:20190603 ----for：解决继承实体字段无法翻译问题------
//for (Field field : record.getClass().getDeclaredFields()) {
for (Field field : ObjConvertUtils.getAllFields(record)) {
//update-end--Author:scott -- Date:20190603 ----for：解决继承实体字段无法翻译问题------
if (field.getAnnotation(Dict.class) != null) {
String datasource = field.getAnnotation(Dict.class).dicDataSource();
String text = field.getAnnotation(Dict.class).dicText();
//获取当前带翻译的值
String key = String.valueOf(item.get(field.getName()));
//翻译字典值对应的txt
String textValue = translateDictValue(datasource, key);
// DICT_TEXT_SUFFIX的值为，是默认值：
// public static final String DICT_TEXT_SUFFIX = "_dictText";
log.debug(" 字典Val : " + textValue);
log.debug(" __翻译字典字段__ " + field.getName() + DICT_TEXT_SUFFIX + "： " + textValue);
//如果给了文本名
if (!StringUtils.isEmpty(text)) {
item.put(text, textValue);
} else {
//走默认策略
item.put(field.getName() + DICT_TEXT_SUFFIX, textValue);
}
}
//date类型默认转换string格式化日期
if (field.getType().getName().equals("java.util.Date") && field.getAnnotation(JsonFormat.class) == null && item.get(field.getName()) != null) {
SimpleDateFormat aDate = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
item.put(field.getName(), aDate.format(new Date((Long) item.get(field.getName()))));
}
}
items.add(item);
}
pageUtils.setData(items);
}
}
/**
* 翻译字典文本
*
* @param datasource
* @param key
* @return
*/
private String translateDictValue(String datasource, String key) {
//如果key为空直接返回就好了
if (ObjConvertUtils.isEmpty(key)) {
return null;
}
StringBuffer textValue = new StringBuffer();
//分割 key 值
String[] keys = key.split(",");
//循环 keys 中的所有值
for (String k : keys) {
String tmpValue = null;
log.debug(" 字典 key : " + k);
if (k.trim().length() == 0) {
continue; //跳过循环
}
tmpValue = dataItemService.selectByDatasourceKey(datasource, k.trim());
if (tmpValue != null) {
if (!"".equals(textValue.toString())) {
textValue.append(",");
}
textValue.append(tmpValue);
}
}
//返回翻译的值
return textValue.toString();
}
}
Dict.java
package com.zhou.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Dict {
/**
* 方法描述: 数据dataSource
* @return 返回类型： String
*/
String dicDataSource();
/**
* 方法描述: 这是返回后Put到josn中的文本 key 值
* @return 返回类型： String
*/
String dicText() default "";
}
PageUtils.java
package com.zhou.util;
import java.io.Serializable;
import java.util.List;
public class PageUtils implements Serializable {
private static final long serialVersionUID = 1L;
//这是总行数
private long total;
//这是保持查询出来的数据
private List<?> data;
/**
*
* @param list 保存数据
* @param total 查到多行数据
*/
public PageUtils(List<?> list, long total) {
this.data = list;
this.total = total;
}
public long getTotal() {
return total;
}
public void setTotal(int total) {
this.total = total;
}
public List<?> getData() {
return data;
}
public void setData(List<?> data) {
this.data = data;
}
public static long getSerialVersionUID() {
return serialVersionUID;
}
}
ObjConvertUtils.java
package com.zhou.util;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class ObjConvertUtils {
/**
* 获取类的所有属性，包括父类
*
* @param object
* @return
*/
public static Field[] getAllFields(Object object) {
Class<?> clazz = object.getClass();
List<Field> fieldList = new ArrayList<>();
while (clazz != null) {
fieldList.addAll(new ArrayList<>(Arrays.asList(clazz.getDeclaredFields())));
clazz = clazz.getSuperclass();
}
Field[] fields = new Field[fieldList.size()];
fieldList.toArray(fields);
return fields;
}
public static boolean isEmpty(Object object) {
if (object == null) {
return (true);
}
if ("".equals(object)) {
return (true);
}
if ("null".equals(object)) {
return (true);
}
return (false);
}
}
友情提示：
真正的自定义注解去做数据字典的转义，应该在切面类引用缓存技术，比如redis；不然的话每次转义一个数字为汉字，还需要查询一次数据库，性能十分低下；