com.baomidou.mybatisplus.extension.plugins.OptimisticLockerInterceptor Maven / Gradle / Ivy
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An enhanced toolkit of Mybatis to simplify development.
package com.baomidou.mybatisplus.extension.plugins;
import java.lang.reflect.Field;
import java.sql.Timestamp;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlCommandType;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.plugin.Intercepts;
import org.apache.ibatis.plugin.Invocation;
import org.apache.ibatis.plugin.Plugin;
import org.apache.ibatis.plugin.Signature;
import com.baomidou.mybatisplus.annotation.Version;
import com.baomidou.mybatisplus.core.conditions.AbstractWrapper;
import com.baomidou.mybatisplus.core.conditions.Wrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.TableFieldInfo;
import com.baomidou.mybatisplus.core.metadata.TableInfo;
import com.baomidou.mybatisplus.core.toolkit.ClassUtils;
import com.baomidou.mybatisplus.core.toolkit.Constants;
import com.baomidou.mybatisplus.core.toolkit.ReflectionKit;
import com.baomidou.mybatisplus.core.toolkit.StringPool;
import com.baomidou.mybatisplus.core.toolkit.TableInfoHelper;
import lombok.Data;
/**
*
* Optimistic Lock Light version
* Intercept on {@link Executor}.update;
* Support version types: int/Integer, long/Long, java.util.Date, java.sql.Timestamp
* For extra types, please define a subclass and override {@code getUpdatedVersionVal}() method.
*
* How to use?
* (1) Define an Entity and add {@link Version} annotation on one entity field.
* (2) Add {@link OptimisticLockerInterceptor} into mybatis plugin.
*
* How to work?
* if update entity with version column=1:
* (1) no {@link OptimisticLockerInterceptor}:
* SQL: update tbl_test set name='abc' where id=100001;
* (2) add {@link OptimisticLockerInterceptor}:
* SQL: update tbl_test set name='abc',version=2 where id=100001 and version=1;
*
*
* @author yuxiaobin
* @since 2017/5/24
*/
@Intercepts({@Signature(type = Executor.class, method = "update", args = {MappedStatement.class, Object.class})})
public class OptimisticLockerInterceptor implements Interceptor {
public static final String MP_OPTLOCK_VERSION_ORIGINAL = "MP_OPTLOCK_VERSION_ORIGINAL";
public static final String MP_OPTLOCK_VERSION_COLUMN = "MP_OPTLOCK_VERSION_COLUMN";
public static final String MP_OPTLOCK_ET_ORIGINAL = "MP_OPTLOCK_ET_ORIGINAL";
private static final String NAME_ENTITY = Constants.ENTITY;
private static final String NAME_ENTITY_WRAPPER = Constants.WRAPPER;
private static final String PARAM_UPDATE_METHOD_NAME = "update";
private final Map, EntityField> versionFieldCache = new ConcurrentHashMap<>();
private final Map, List> entityFieldsCache = new ConcurrentHashMap<>();
@Override
@SuppressWarnings("unchecked")
public Object intercept(Invocation invocation) throws Throwable {
Object[] args = invocation.getArgs();
MappedStatement ms = (MappedStatement) args[0];
if (SqlCommandType.UPDATE != ms.getSqlCommandType()) {
return invocation.proceed();
}
Object param = args[1];
// wrapper = ew
Wrapper ew = null;
// entity = et
Object et = null;
if (param instanceof Map) {
Map map = (Map) param;
if (map.containsKey(NAME_ENTITY)) {
//updateById(et), update(et, wrapper);
et = map.get(NAME_ENTITY);
}
if (map.containsKey(NAME_ENTITY_WRAPPER)) {
// mapper.update(updEntity, QueryWrapper<>(whereEntity);
ew = (Wrapper) map.get(NAME_ENTITY_WRAPPER);
}
if (et != null) {
// entity
String methodId = ms.getId();
String updateMethodName = methodId.substring(ms.getId().lastIndexOf(StringPool.DOT) + 1);
Class entityClass = et.getClass();
TableInfo tableInfo = TableInfoHelper.getTableInfo(entityClass);
// fixed github 299
while (tableInfo == null && entityClass != null) {
entityClass = ClassUtils.getUserClass(entityClass.getSuperclass());
tableInfo = TableInfoHelper.getTableInfo(entityClass);
}
EntityField entityVersionField = this.getVersionField(entityClass, tableInfo);
if (entityVersionField == null) {
return invocation.proceed();
}
Field versionField = entityVersionField.getField();
Object originalVersionVal = entityVersionField.getField().get(et);
Object updatedVersionVal = getUpdatedVersionVal(originalVersionVal);
if (PARAM_UPDATE_METHOD_NAME.equals(updateMethodName)) {
// update(entity, wrapper)
if (originalVersionVal != null) {
if (ew == null) {
AbstractWrapper aw = new QueryWrapper();
aw.eq(entityVersionField.getColumnName(), originalVersionVal);
map.put(NAME_ENTITY_WRAPPER, aw);
versionField.set(et, updatedVersionVal);
} else if (ew instanceof AbstractWrapper) {
AbstractWrapper aw = (AbstractWrapper) ew;
aw.eq(entityVersionField.getColumnName(), originalVersionVal);
versionField.set(et, updatedVersionVal);
//TODO: should remove version=oldval condition from aw; 0827
}
}
return invocation.proceed();
} else {
dealUpdateById(entityClass, et, entityVersionField, originalVersionVal, updatedVersionVal, map);
Object resultObj = invocation.proceed();
if (resultObj instanceof Integer) {
Integer effRow = (Integer) resultObj;
if (updatedVersionVal != null && effRow != 0 && versionField != null) {
//updated version value set to entity.
versionField.set(et, updatedVersionVal);
}
}
return resultObj;
}
}
}
return invocation.proceed();
}
/**
* 处理updateById(entity)乐观锁逻辑
*
* @param entityClass 实体类
* @param et 参数entity
* @param entityVersionField
* @param originalVersionVal 原来版本的value
* @param updatedVersionVal 乐观锁自动更新的新value
* @param map
*/
private void dealUpdateById(Class entityClass, Object et, EntityField entityVersionField,
Object originalVersionVal, Object updatedVersionVal, Map map) throws IllegalAccessException {
if (originalVersionVal == null) {
return;
}
List fields = getEntityFields(entityClass);
Map entityMap = new HashMap<>();
for (EntityField ef : fields) {
Field fd = ef.getField();
entityMap.put(fd.getName(), fd.get(et));
}
Field versionField = entityVersionField.getField();
String versionColumnName = entityVersionField.getColumnName();
//update to cache
entityVersionField.setColumnName(versionColumnName);
entityMap.put(versionField.getName(), updatedVersionVal);
entityMap.put(MP_OPTLOCK_VERSION_ORIGINAL, originalVersionVal);
entityMap.put(MP_OPTLOCK_VERSION_COLUMN, versionColumnName);
entityMap.put(MP_OPTLOCK_ET_ORIGINAL, et);
map.put(NAME_ENTITY, entityMap);
}
/**
* This method provides the control for version value.
* Returned value type must be the same as original one.
*
* @param originalVersionVal
* @return updated version val
*/
protected Object getUpdatedVersionVal(Object originalVersionVal) {
if (null == originalVersionVal) {
return null;
}
Class versionValClass = originalVersionVal.getClass();
if (long.class.equals(versionValClass)) {
return ((long) originalVersionVal) + 1;
} else if (Long.class.equals(versionValClass)) {
return ((Long) originalVersionVal) + 1;
} else if (int.class.equals(versionValClass)) {
return ((int) originalVersionVal) + 1;
} else if (Integer.class.equals(versionValClass)) {
return ((Integer) originalVersionVal) + 1;
} else if (Date.class.equals(versionValClass)) {
return new Date();
} else if (Timestamp.class.equals(versionValClass)) {
return new Timestamp(System.currentTimeMillis());
} else if (LocalDateTime.class.equals(versionValClass)) {
return LocalDateTime.now();
}
//not supported type, return original val.
return originalVersionVal;
}
@Override
public Object plugin(Object target) {
if (target instanceof Executor) {
return Plugin.wrap(target, this);
}
return target;
}
@Override
public void setProperties(Properties properties) {
// to do nothing
}
private EntityField getVersionField(Class parameterClass, TableInfo tableInfo) {
synchronized (parameterClass.getName()) {
if (versionFieldCache.containsKey(parameterClass)) {
return versionFieldCache.get(parameterClass);
}
// 缓存类信息
EntityField field = this.getVersionFieldRegular(parameterClass, tableInfo);
if (field != null) {
versionFieldCache.put(parameterClass, field);
return field;
}
return null;
}
}
/**
*
* 反射检查参数类是否启动乐观锁
*
*
* @param parameterClass 实体类
* @param tableInfo 实体数据库反射信息
* @return
*/
private EntityField getVersionFieldRegular(Class parameterClass, TableInfo tableInfo) {
if (parameterClass != Object.class) {
for (Field field : parameterClass.getDeclaredFields()) {
if (field.isAnnotationPresent(Version.class)) {
field.setAccessible(true);
String versionPropertyName = field.getName();
String versionColumnName = null;
for (TableFieldInfo fieldInfo : tableInfo.getFieldList()) {
if (versionPropertyName.equals(fieldInfo.getProperty())) {
versionColumnName = fieldInfo.getColumn();
}
}
return new EntityField(field, true, versionColumnName);
}
}
// 递归父类
return this.getVersionFieldRegular(parameterClass.getSuperclass(), tableInfo);
}
return null;
}
/**
* 获取实体的反射属性(类似getter)
*
* @param parameterClass
* @return
*/
private List getEntityFields(Class parameterClass) {
if (entityFieldsCache.containsKey(parameterClass)) {
return entityFieldsCache.get(parameterClass);
}
List fields = this.getFieldsFromClazz(parameterClass, null);
entityFieldsCache.put(parameterClass, fields);
return fields;
}
private List getFieldsFromClazz(Class parameterClass, List fieldList) {
if (fieldList == null) {
fieldList = new ArrayList<>();
}
List fields = ReflectionKit.getFieldList(parameterClass);
for (Field field : fields) {
field.setAccessible(true);
if (field.isAnnotationPresent(Version.class)) {
fieldList.add(new EntityField(field, true));
} else {
fieldList.add(new EntityField(field, false));
}
}
return fieldList;
}
@Data
private class EntityField {
EntityField(Field field, boolean version) {
this.field = field;
this.version = version;
}
public EntityField(Field field, boolean version, String columnName) {
this.field = field;
this.version = version;
this.columnName = columnName;
}
private Field field;
private boolean version;
private String columnName;
}
}
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