---
sidebar_position: 4
title: RPC 远程调用
description: ZHub RPC 远程调用功能详解，包含基础类型、类型化调用和多客户端示例
---

# RPC 远程调用

![rpc-flow.png](https://img.1216.top/docs/zhub/rpc-flow.png)

## 使用场景

- **微服务间通信**：用户服务调用订单服务
- **数据查询服务**：统一的数据查询接口
- **业务逻辑封装**：封装复杂业务逻辑供其他模块调用
- **第三方服务集成**：调用外部 API

## 基础示例

**重要**：RPC 通讯要求每个客户端使用唯一的 appid，消息回复使用此标识。

### 基础类型 RPC

**服务端**：
```java
// 订阅 RPC 服务
zhub.rpcSubscribe("rpc-b", IType.STRING, r -> {
    String str = r.getValue();
    System.out.println("接收到: " + str);
    return r.render("处理结果: " + str);
});
```

**客户端**：
```java
// 调用 RPC 服务
RpcResult<String> result = zhub.rpc("rpc-b", "hello rpc", IType.STRING);
System.out.println("结果: " + result.getResult());
```

### 类型化 RPC

**定义类型**：
```java
// 请求类型
public class UserQueryRequest {
    private String userId;
    private String queryType;
    // getter/setter...
}

// 响应类型
public class UserInfoResponse {
    private String userId;
    private String username;
    private String email;
    private long lastLoginTime;
    // getter/setter...
}
```

**服务端**：
```java
zhub.rpcSubscribe("user-get-info", new TypeToken<UserQueryRequest>(){}, request -> {
    String userId = request.getUserId();
    String queryType = request.getQueryType();
    return request.render(new UserInfoResponse(userId, "张三", "zhangsan@example.com", System.currentTimeMillis()));
});
```

**客户端**：
```java
UserQueryRequest request = new UserQueryRequest("12345", "basic");
RpcResult<UserInfoResponse> result = zhub.rpc("user-get-info", request, new TypeToken<UserInfoResponse>(){});

if (result.isSuccess()) {
    UserInfoResponse userInfo = result.getResult();
    System.out.println("用户: " + userInfo.getUsername());
} else {
    System.out.println("调用失败: " + result.getError());
}
```

### 多客户端示例

**服务端**：
```java
ZHubClient serviceProvider = new ZHubClient("127.0.0.1:1216", "service-group", "service-provider-001", "token-12345");

// 单个 RPC 服务
serviceProvider.rpcSubscribe("user-get-info", IType.STRING, request -> {
    return request.render("用户信息: " + request.getValue());
});

// 多个 RPC 服务（使用TypeToken）
serviceProvider.rpcSubscribe("user-get-info,user-get-profile", new TypeToken<UserQueryRequest>(){}, request -> {
    switch (request.getQueryType()) {
        case "getInfo":
            return request.render(new UserInfoResponse(request.getUserId(), "张三", "zhangsan@example.com", System.currentTimeMillis()));
        case "getProfile":
            return request.render(new UserProfileResponse(request.getUserId(), "张三", 25, "北京"));
        default:
            return request.render(new UserInfoResponse(request.getUserId(), "未知用户", "", 0));
    }
});
```

**客户端A**：
```java
ZHubClient clientA = new ZHubClient("127.0.0.1:1216", "client-group", "client-a-001", "token-12345");
RpcResult<String> result = clientA.rpc("user-get-info", "user123", IType.STRING);
System.out.println("结果: " + result.getResult());
```

**客户端B**：
```java
ZHubClient clientB = new ZHubClient("127.0.0.1:1216", "client-group", "client-b-002", "token-12345");
UserQueryRequest request = new UserQueryRequest("user456", "basic");
RpcResult<UserInfoResponse> result = clientB.rpc("user-get-info", request, new TypeToken<UserInfoResponse>(){});
if (result.isSuccess()) {
    System.out.println("用户: " + result.getResult().getUsername());
}
```

## 类型化 RPC

### 使用 TypeToken 构建具体类型

**服务端**：
```java
// 定义请求和响应类型
public class OrderRequest {
    private String orderId;
    private String queryType;
    // getter/setter...
}

public class OrderResponse {
    private String orderId;
    private String status;
    private BigDecimal amount;
    // getter/setter...
}

// 订阅类型化 RPC
zhub.rpcSubscribe("order-get-details", new TypeToken<OrderRequest>(){}, request -> {
    OrderResponse response = new OrderResponse();
    response.setOrderId(request.getOrderId());
    response.setStatus("已支付");
    response.setAmount(new BigDecimal("99.99"));
    return request.render(response);
});
```

**客户端**：
```java
// 调用类型化 RPC
OrderRequest request = new OrderRequest("ORDER-123", "details");
RpcResult<OrderResponse> result = zhub.rpc("order-get-details", request, new TypeToken<OrderResponse>(){});

if (result.isSuccess()) {
    OrderResponse order = result.getResult();
    System.out.println("订单状态: " + order.getStatus());
    System.out.println("订单金额: " + order.getAmount());
}
```