mybatis新增对象自动生成uuid方案
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mybatis新增对象时, 使用拦截器自动生成uuid方案
有了它不再去xml中手动添加selectKey了, 生成id方案实现类自行实现, 实现IdGenerator接口便可, 主要代码由公司同事编写, 我进行改造
使用时可以在id字段上添加@Id注解, 也可以在getId方法上添加或者不添加, 但是主键名字必须是id, 类型必须是String
@Target({ METHOD, FIELD }) @Retention(RUNTIME) public @interface Id { Class<?> strategy() default UUIDGenerator.class; }
public interface IdGenerator { Serializable generator(); }
public class PropertySet { private Set<ProPertyStrategyMapper> propertys = new HashSet<ProPertyStrategyMapper>(); private Class<?> entity; @SuppressWarnings("unused") private PropertySet() { } public PropertySet(Class<?> entity) { this.entity = entity; this.build(); } public Set<ProPertyStrategyMapper> getPropertys() { return propertys; } public void setPropertys(Set<ProPertyStrategyMapper> propertys) { this.propertys = propertys; } public PropertySet build() { List<Field> fieldList = new ArrayList<>(); Class clazz = entity; while (null != clazz) { Field[] declaredFields = clazz.getDeclaredFields(); fieldList.addAll(Arrays.asList(declaredFields)); clazz = clazz.getSuperclass(); } for (Field field : fieldList) { if ("serialVersionUID".equals(field.getName())) continue; field.setAccessible(true); PropertyDescriptor propertyDescriptor = null; try { propertyDescriptor = new PropertyDescriptor(field.getName(), entity); } catch (IntrospectionException e) { e.printStackTrace(); } if (propertyDescriptor == null) continue; // 获取类的get方法 Method method = propertyDescriptor.getReadMethod(); if (method == null) { continue; } if (field.isAnnotationPresent(Id.class)) { Id id = field.getAnnotation(Id.class); if (null == id.strategy()) { continue; } Class<?> strategy = id.strategy(); Object newInstance = null; try { newInstance = strategy.newInstance(); } catch (InstantiationException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } if (!(newInstance instanceof IdGenerator)) { continue; } IdGenerator idGenerator = (IdGenerator) newInstance; ProPertyStrategyMapper proPertyStrategyMapper = new ProPertyStrategyMapper(field.getName(), idGenerator); propertys.add(proPertyStrategyMapper); } else if (method.isAnnotationPresent(Id.class)) { Id id = method.getAnnotation(Id.class); if (id.strategy() == null) { continue; } Class<?> generator = id.strategy(); Object object = null; try { object = generator.newInstance(); } catch (InstantiationException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } if (!(object instanceof IdGenerator)) { continue; } IdGenerator idGenerator = (IdGenerator) object; ProPertyStrategyMapper proPertyStrategyMapper = new ProPertyStrategyMapper(field.getName(), idGenerator); propertys.add(proPertyStrategyMapper); break; } else if (String.class.equals(field.getType()) && "id".equalsIgnoreCase(field.getName())) { IdGenerator idGenerator = new UUIDGenerator(); ProPertyStrategyMapper proPertyStrategyMapper = new ProPertyStrategyMapper(field.getName(), idGenerator); propertys.add(proPertyStrategyMapper); } } return this; } }
public class ProPertyStrategyMapper { private String propertyName; private IdGenerator generator; public ProPertyStrategyMapper(String propertyName, IdGenerator generator) { super(); this.propertyName = propertyName; this.setGenerator(generator); } public String getPropertyName() { return propertyName; } public void setPropertyName(String propertyName) { this.propertyName = propertyName; } public IdGenerator getGenerator() { return generator; } public void setGenerator(IdGenerator generator) { this.generator = generator; } }
public class UUIDGenerator implements IdGenerator { @Override public Serializable generator() { // 自行修改此处生成id方案 return UUID.randomUUID().toString(); } }
@Intercepts({ @Signature(type = Executor.class, method = "update", args = { MappedStatement.class, Object.class }) }) public class UUIDInterceptor implements Interceptor { @Override public Object intercept(Invocation invocation) throws Throwable { Object[] args = invocation.getArgs(); if (args == null || args.length != 2 || !(args[0] instanceof MappedStatement) || (args[1] instanceof Map)) { return invocation.proceed(); } MappedStatement mappedStatement = (MappedStatement) args[0]; SqlCommandType sqlCommandType = mappedStatement.getSqlCommandType(); if (!SqlCommandType.INSERT.equals(sqlCommandType)) { return invocation.proceed(); } setDefultProperty(args[1]); return invocation.proceed(); } public void setDefultProperty(Object obj) { PropertySet propertySet = new PropertySet(obj.getClass()); Set<ProPertyStrategyMapper> propers = propertySet.getPropertys(); if (propers == null || propers.isEmpty()) return; for (ProPertyStrategyMapper pro : propers) { try { BeanUtils.setProperty(obj, pro.getPropertyName(), pro.getGenerator().generator()); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } } } @Override public Object plugin(Object target) { return Plugin.wrap(target, this); } @Override public void setProperties(Properties properties) { System.out.println("init UUIDInterceptor"); } }
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