mybatis新增对象自动生成uuid方案

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");
	}

}