以HTTP接口形式的应用,是目前大部分中小型企业最常见的微服务夸语言交互的实现方式
即:定义多个接口,外部调用,经网关解析进行分发，小编遇到的这种情况是，有多个服务，每个服务都需要单独有网关开墙，很是头疼，每上线一个服务都需要网关配置，极其头疼，再次实现一种暴露一个接口，通过参数来实现调用不同的方法的案例
实现方案:
-
- 自定义注解 APiMapping
- 自定义ApiGateWayServlet
- 利用 Spring IOC 拆分方法并与 ApiMaping 做绑定由 ApiStore中HashMap维护
api注解: APIMapping
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface APIMapping {
String value();
RequestMethod method();
}通过注解对业务方法标记
@APIMapping(value = "biz.api.order",method = RequestMethod.GET)
public OrderInfo getOrderInfo(String orderId) {
OrderInfo orderInfo = OrderInfo.builder().id(orderId).name("测试订单").price(12.2).build();
return orderInfo;
}
@APIMapping(value = "biz.api.order2",method = RequestMethod.POST)
public OrderInfo getOrderDo(OrderInfo orderInfo){
return orderInfo;
}利用Spring 上下文对标记的方法进行绑定 初始化时候，扫描APIMapping接口
String[] names = applicationContext.getBeanDefinitionNames();
Class<?> type;
for (String name : names) {
type = applicationContext.getType(name);
for (Method method : type.getDeclaredMethods()) {
APIMapping apiMapping = method.getDeclaredAnnotation(APIMapping.class);
if (apiMapping!=null){
addApiItem(apiMapping,name,method);
}
}
}
重写自定义Servlet方法中的POST和GET
public class ApiGateWayServlet extends HttpServlet {
private ApplicationContext applicationContext;
private ApiGateWayHandler apiGateWayHandler;
@Override
public void init() throws ServletException {
super.init();
applicationContext = WebApplicationContextUtils.getWebApplicationContext(getServletContext());
apiGateWayHandler = applicationContext.getBean(ApiGateWayHandler.class);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
apiGateWayHandler.handle(req,resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
apiGateWayHandler.handle(req,resp);
}
}
根据接口绑定获取到执行的方法,利用反射执行
public class ApiRunnable {
private String apiName;
private Method targetMethod;
private String targetName;
private Object target;
private String Method;
Object result = null;
Object target = apiRunable.getTarget();
Method targetMethod = apiRunable.getTargetMethod();
Set<Method> methods = ReflectionUtils.getMethods(target.getClass(), ReflectionUtils.withName(targetMethod.getName()));
Iterator<Method> iterator = methods.iterator();
Method method = null;
while (iterator.hasNext()) {
method = iterator.next();
}
Class<?>[] parameterTypes = method.getParameterTypes();
try {
Class<?> aClass = Class.forName(parameterTypes[0].getName());
Class<String> stringClass = String.class;
if (stringClass == aClass) {
result = apiRunable.run(parameter);
....