java - 填充 proto 的重复元素

Question

尝试生成部门数组，这是我的尝试。

原始文件

service DepartmentService {
    rpc findAll(Request) returns (Response);
}

message Department {
    int64 id = 1;
    string name = 2;
}

message Request {
    string id = 1;
}

message Response {
    int32 code = 1;
    repeated Department departments = 2;
}

对应的java代码。

public void findAll(DepartmentOuter.Request request, StreamObserver<DepartmentOuter.Response> responseObserver) {
    MongoCursor<Document> cursor = database
            .getCollection("department")
            .find()
            .iterator();

    DepartmentOuter.Response.Builder builder = DepartmentOuter.Response.newBuilder();
    while (cursor.hasNext()) {
        Document document = cursor.next();

        DepartmentOuter.Department department = DepartmentOuter.Department
                .newBuilder()
                .setId(Integer.parseInt(document.getString("_id")))
                .setName(document.getString("name")).build();

        builder.addDepartments(department);


    }



responseObserver.onNext(DepartmentOuter.Response.newBuilder().setCode(0).setDepartments(builder).build());
}

我在这段代码的最后一行遇到了问题。如何将填充输出发送到客户端？

responseObserver.onNext(DepartmentOuter.Response.newBuilder().setCode(0).setDepartments(builder).build());

<小时/>

编辑 - 重命名后

原始文件

service DepartmentService {
    rpc findAll(Request) returns (Response);
}

message Department {
    int64 id = 1;
    string name = 2;
}

message Request {
    string id = 1;
}

message Response {
    int32 code = 1;
    repeated Department department = 2;
}

@Override
public void findAll(DepartmentOuter.Request request, StreamObserver<DepartmentOuter.Response> responseObserver) {
    MongoCursor<Document> cursor = database
            .getCollection("department")
            .find()
            .iterator();

    DepartmentOuter.Response.Builder builder = DepartmentOuter.Response.newBuilder();
    while (cursor.hasNext()) {
        Document document = cursor.next();

        DepartmentOuter.Department department = DepartmentOuter.Department
                .newBuilder()
                .setId(Integer.parseInt(document.getString("_id")))
                .setName(document.getString("name")).build();

        builder.addDepartment(department);
    }

    responseObserver.onNext(DepartmentOuter.Response.newBuilder().setCode(0).setDepartment.build());
}

Answer 1

responseObserver.onNext(DepartmentOuter.Response.newBuilder().setCode(0).setDepartments(builder).build());

departments 是一个重复字段，因此应该是 addDepartments 而不是 setDepartments。您可以调用 setDepartments(someIndex, someDepartment)，但只有在您之前至少向构建器添加了 someIndex+1 值时才有效；你还没有，因为它是一个新的构建器。

但是builder无论如何都是一个DepartmentOuter.Response.Builder，而不是一个Department，所以这也不起作用。目前尚不清楚您打算做什么；也许:

responseObserver.onNext(builder.setCode(0).build());