一、背景：

后台系统配置越来越多的出现需要进行日志记录的功能，且当前已有日志记录不可复用，需要统一日志记录格式，提高日志记录开发效率。

二、预期效果展示：

新建动作：

修改动作：

删除动作：

三、数据存储：

注：可以选择其他存储方式，这里只简单举个例子

1`biz_id` bigint(20) NOT NULL DEFAULT 0 COMMENT '业务id',
2`biz_type` tinyint(4) NOT NULL DEFAULT 0 COMMENT '业务类型',
3`operator_id` varchar(128) NOT NULL DEFAULT '' COMMENT '操作人',
4`operate_content` text COMMENT '操作内容',
5`change_before` text COMMENT '修改前',
6`change_after` text COMMENT '修改后',
7`create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间'

四、原理简述：

日志构建关注两个对象，一个是修改前，修改后：

修改前：null + 修改后：X = 新建

修改前：Y + 修改后：X = 更新

修改前：Y + 修改后：null = 删除

修改内容判断依据传入的两个对象，对两个对象的每个属性进行逐一对比，如果发生变化则是需要进行日志记录字段；关注的属性使用注解进行标注。

五、具体实现：

注解：

1@Target(ElementType.FIELD)
2@Retention(RetentionPolicy.RUNTIME)
3@Inherited
4@Documented
5public @interface LogField {
6
7    String name() default "";
8
9    String valueFun() default "";
10
11    boolean spliceValue() default true;
12}
13
14

name: name值表示该字段如果被修改，应在日志中记录的字段名；默认取字段名

valueFun: 表示获取改变字段内容的获取方法；默认取字段值，若valueFun方法不存在，则取默认值

spliceValue: 日志是否需要拼接变更内容，默认拼接

注解处理：

1@Service
2@Slf4j
3public class OperateLogService {
4    @Resource
5    private CommonOperateLogService commonOperateLogService;
6
7    enum ActionEnum{
8        ADD("新建"),
9        UPDATE("修改"),
10        DELETE("删除");
11
12        ActionEnum(String desc) {
13            this.desc = desc;
14        }
15        public String desc;
16    }
17
18    private int insertLog(CommonOperatorLog commonOperatorLog){
19        String result = commonOperateLogService.insertLog(JSON.toJSONString(commonOperatorLog));
20        Response response = JSON.parseObject(result, Response.class);
21        return Objects.isNull(response) || ApiResponse.Status.fail.equals(response.getStatus()) ? 0 : (int) response.getContent();
22    }
23
24    public PageOutput<CommonOperatorLog> queryList(Long bizId, Integer bizType, Integer pageNum, Integer pageSize){
25        String result = commonOperateLogService.queryLog(bizId, bizType, pageNum, pageSize);
26        PageOutput pageOutput = JSON.parseObject(result, new TypeReference<PageOutput<CommonOperatorLog>>() {});
27        return pageOutput;
28    }
29
30    public <T> void saveLog(String operatorId,Long bizId, Integer bizType, T target, T original){
31        if(StringUtils.isBlank(operatorId) || (Objects.isNull(target) && Objects.isNull(original))){
32            throw new IllegalArgumentException();
33        }
34        if(Objects.nonNull(target) && Objects.nonNull(original) && !target.getClass().isAssignableFrom(original.getClass())){
35            throw new IllegalArgumentException();
36        }
37        ActionEnum action = getAction(target, original);
38        List<Triple<String, String, LogField>> changeInfos = getChangeInfoList(target, original);
39        List<String> changeInfoList = new ArrayList<>();
40        if(CollectionUtils.isEmpty(changeInfos) && !ActionEnum.UPDATE.equals(action)){
41            changeInfoList.add(0, action.desc);
42        }else if (CollectionUtils.isEmpty(changeInfos)){
43            return;
44        }else {
45            changeInfoList = changeInfos.stream().map(i -> i.getRight().spliceValue() ?
46                            action.desc + StringUtils.joinWith("为:", i.getLeft(), i.getMiddle()) :
47                            action.desc + StringUtils.join("了", i.getLeft()))
48                    .collect(Collectors.toList());
49        }
50
51        String operateContext = StringUtils.join(changeInfoList, "\n");
52        operateContext = operateContext.replaceAll("\"","")
53                .replaceAll("\\[","").replaceAll("\\]","");
54        CommonOperatorLog operatorLog = new CommonOperatorLog();
55        operatorLog.setBizId(bizId);
56        operatorLog.setBizType(bizType);
57        operatorLog.setOperateContent(operateContext);
58        operatorLog.setOperatorId(operatorId);
59        operatorLog.setChangeBefore(JSON.toJSONString(original));
60        operatorLog.setChangeAfter(JSON.toJSONString(target));
61        this.insertLog(operatorLog);
62    }
63
64    private ActionEnum getAction(Object target, Object original){
65        ActionEnum action = ActionEnum.ADD;
66        if(Objects.nonNull(target) && Objects.nonNull(original)){
67            action = ActionEnum.UPDATE;
68        }else if(Objects.nonNull(target)){
69            action = ActionEnum.ADD;
70        }else if (Objects.nonNull(original)){
71            action = ActionEnum.DELETE;
72        }
73        return action;
74    }
75
76
77    private<T> List<Triple<String, String, LogField>> getChangeInfoList(T target, T original){
78        if(Objects.isNull(target) || Objects.isNull(original)){
79            return new ArrayList<>();
80        }        
81        List<Pair<Field, Object>> targetFields = allFields(target);
82        List<Pair<Field, Object>> originalFields = allFields(original);
83        if(targetFields.size() != originalFields.size()){
84            //理论上不可能执行到这
85            throw new IllegalArgumentException();
86        }
87
88        List<Triple<String, String, LogField>> result = new ArrayList<>();
89        for (int i = 0; i < targetFields.size(); i++) {
90            Pair<Field, Object> targetField = targetFields.get(i);
91            Pair<Field, Object> originalField = originalFields.get(i);
92            ReflectionUtils.makeAccessible(targetField.getKey());
93            ReflectionUtils.makeAccessible(originalField.getKey());
94            Object targetValue = ReflectionUtils.getField(targetField.getKey(), targetField.getValue());
95            Object originalValue = ReflectionUtils.getField(originalField.getKey(), originalField.getValue());
96               if(targetValue != originalValue && (Objects.isNull(targetValue) ||
97                        (!targetValue.equals(originalValue) &&
98                        compareTo(Pair.of(targetField.getKey(), targetValue), Pair.of(originalField.getKey(), originalValue)) &&
99                        !JSON.toJSONString(targetValue).equals(JSON.toJSONString(originalValue))))){
100                result.add(Triple.of(getFieldName(targetField.getKey()), getFieldValue(targetField.getKey(), targetField.getValue()), targetField.getKey().getAnnotation(LogField.class)));
101            }
102        }
103        return result;
104    }
105
106    private boolean compareTo(Pair<Field, Object> targetField, Pair<Field, Object> originalField){
107        Field field = targetField.getKey();
108        Object targetValue = targetField.getValue();
109        Object originalValue = originalField.getValue();
110        boolean canCompare = Arrays.stream(field.getType().getInterfaces()).anyMatch(i -> Comparable.class.getName().equals(i.getName()));
111        if(canCompare && Objects.nonNull(targetValue) && Objects.nonNull(originalValue)){
112            Method compareTo = ReflectionUtils.findMethod(field.getType(), "compareTo", field.getType());
113            if(Objects.isNull(compareTo)){
114                return true;
115            }
116            Object compared = ReflectionUtils.invokeMethod(compareTo, targetValue, originalValue);
117            return (int)compared != 0 ;
118        }
119        return true;
120    }
121
122    private <T> List<Pair<Field, Object>> allFields(T obj){
123        List<Triple<Field, Object, Boolean>> targetField = findField(obj);
124        List<Triple<Field, Object, Boolean>> allField = Lists.newArrayList(targetField);
125        List<Triple<Field, Object, Boolean>> needRemove = new ArrayList<>();
126        for (int i = 0; i < allField.size(); i++) {
127            Triple<Field, Object, Boolean> fieldObjectDes = allField.get(i);
128            if(!fieldObjectDes.getRight()){
129                ReflectionUtils.makeAccessible(fieldObjectDes.getLeft());
130                Object fieldV = ReflectionUtils.getField(fieldObjectDes.getLeft(), fieldObjectDes.getMiddle());
131                List<Triple<Field, Object, Boolean>> fieldList = findField(fieldV);
132                if(CollectionUtils.isNotEmpty(fieldList)){
133                    allField.addAll(fieldList);
134                    needRemove.add(fieldObjectDes);
135                }
136            }
137        }
138
139        if(CollectionUtils.isNotEmpty(needRemove)){
140            allField.removeAll(needRemove);
141        }
142        return allField.stream().map(i->Pair.of(i.getLeft(), i.getMiddle())).collect(Collectors.toList());
143    }
144
145    private <T> List<Triple<Field, Object, Boolean>> findField(T obj){
146        Class<?> objClass = obj.getClass();
147        Field[] declaredFields = objClass.getDeclaredFields();
148        List<Field> allFields = Lists.newArrayList(declaredFields);
149        if(Objects.nonNull(objClass.getSuperclass())){
150            Field[] superClassFields = objClass.getSuperclass().getDeclaredFields();
151            allFields.addAll(Arrays.asList(superClassFields));
152        }
153        List<Triple<Field, Object, Boolean>> result = new ArrayList<>();
154        for (Field declaredField : allFields) {
155            LogField annotation = declaredField.getAnnotation(LogField.class);
156            if(Objects.nonNull(annotation)){
157                result.add(Triple.of(declaredField, obj, declaredField.getType().getPackage().getName().startsWith("java")));
158            }
159        }
160        return result;
161    }
162
163
164    private String getFieldName(Field field){
165        LogField annotation = field.getAnnotation(LogField.class);
166        String name = annotation.name();
167        if(StringUtils.isBlank(name)){
168            name = field.getName();
169        }
170        return name;
171    }
172
173    private <T> String getFieldValue(Field field, T targetObj){
174        LogField annotation = field.getAnnotation(LogField.class);
175        if(!annotation.spliceValue()){
176            return "";
177        }
178        String valueFun = annotation.valueFun();
179        if(StringUtils.isBlank(valueFun)){
180            Object fieldValue = ReflectionUtils.getField(field, targetObj);
181            return getStrValue(fieldValue);
182        }else {
183            Method valueMethod = ReflectionUtils.findMethod(targetObj.getClass(), valueFun);
184            if(Objects.isNull(valueMethod)){
185                Object fieldValue = ReflectionUtils.getField(field, targetObj);
186                return getStrValue(fieldValue);
187            }else {
188                ReflectionUtils.makeAccessible(valueMethod);
189                Object invokeMethodRes = ReflectionUtils.invokeMethod(valueMethod, targetObj);
190                return getStrValue(invokeMethodRes);
191            }
192        }
193    }
194
195    private String getStrValue(Object fieldValue){
196        List<String> emptyStr = ImmutableList.of("\"\"", "{}","[]");
197        String value = Objects.isNull(fieldValue) ? "无" : JSON.toJSONString(fieldValue);
198        return emptyStr.contains(value) ? "无" : value;
199    }
200}
201
202

六、使用示例：

1、使用的日志记录对象（这个对象只为日志服务）

1public class SubsidyRateLog {
2
3    @LogField(name = "补贴率名称")
4    private String name;
5
6    @LogField(name = "适用城市", valueFun = "getCityNames")
7    private List<Integer> cityIds;
8
9    private List<String> cityNames;
10}
11
12

name是直接展示字段，所以修改值即name本身的值；cityIds 是我们关心比较字段，当它值不一样时进行字段value 值获取，这个值是展示在前端的，所以可以根据需要进行格式定义，默认是将取到的值进行toJSON；当前例子中获取的是getCityNames方法返回的值；

2、无专用日志对象（大多数时候我们有自己的实体对象，但不包含具体日志描述字段），需要进行继承

1public class SubsidyRate {
2
3    @LogField(name = "补贴率名称")
4    private String name;
5
6    @LogField(name = "适用城市", valueFun = "getCityNames")
7    private List<Integer> cityIds;
8}
9
10@Data
11public class SubsidyRateLog extends SubsidyRate{
12    
13    private List<String> cityNames;
14}
15
16
17

此方式适用于兼容现有对象，而不去破坏现有对象的完整性

3、对象包含子对象（比较复杂的大对象，如Task中的券信息）

1public class SubsidyRateLog {
2
3    @LogField(name = "补贴率名称")
4    private String name;
5
6    @LogField
7    private Address address;
8}
9
10public class Address {
11    @LogField(name = "省份")
12    private String province;
13    @LogField(name = "城市")
14    private String city;
15}
16
17

此情况下会将所有信息平铺，如果 Address 中没有_LogField_ 注解，那么会直接使用将获取address值，如果存在注解，那么将忽略address本身，只关注注解字段。

作者：京东零售祁伟

来源：京东云开发者社区转载请注明来源

一种简化操作日志记录方案 | 京东云技术团队