深入剖析Kubernetes

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");
    }