rust - 找不到 nickel.rs 帖子重定向

Question

我正在使用 nickel.rs、PostgreSQL 和 Angular.js。我可以使用 HTTP POST 插入到我的表中:

// insert
{
    let conn = shared_connection.clone();
    router.post("/api/movies", middleware! { |request, mut response|
        let conn = conn.lock().unwrap();
        let stmt = match conn.prepare("insert into movie (title, releaseYear, director, genre)
            values ($1, $2, $3, $4)") {
            Ok(stmt) => stmt,
            Err(e) => {
                return response.send(format!("Preparing query failed: {}", e));
            }
        };

        let movie = request.json_as::<MovieInsert>().unwrap();
        match stmt.execute(&[
            &movie.title.to_string(),
            &movie.releaseYear,
            &movie.director.to_string(),
            &movie.genre.to_string()
        ]) {
            Ok(v) => println!("Inserting movie was Success."),
            Err(e) => println!("Inserting movie failed. => {:?}", e),
        };

        // ERROR (1)
        // return response.set(Location("/".into()));

    });
}

我知道这很好用，因为该行已插入到 PostgreSQL 表中。但是，Chrome 网络浏览器显示错误:

POST http://localhost:6767/api/movies 404 (Not Found)

我还在ERROR (1)中添加了代码行

response.set(Location("/".into()));

然而，控制台显示错误。

 expected `core::result::Result<nickel::middleware::Action<nickel::response::Response<'mw, _>, nickel::response::Response<'mw, _, hyper::net::Streaming>>, nickel::nickel_error::NickelError<'mw, _>>`,
    found `&mut nickel::response::Response<'_, _>`
(expected enum `core::result::Result`,
    found &-ptr)

现在我的代码应用了 Shepmaster 所说的内容。

// insert
{
    let conn = shared_connection.clone();
    router.post("/api/movies", middleware! { |request, mut response|
        let conn = conn.lock().unwrap();
        let stmt = match conn.prepare("insert into movie (title, releaseYear, director, genre)
            values ($1, $2, $3, $4)") {
            Ok(stmt) => stmt,
            Err(e) => {
                return response.send(format!("Preparing query failed: {}", e));
            }
        };

        let movie = request.json_as::<MovieInsert>().unwrap();
        match stmt.execute(&[
            &movie.title.to_string(),
            &movie.releaseYear,
            &movie.director.to_string(),
            &movie.genre.to_string()
        ]) {
            Ok(v) => println!("Inserting movie was Success."),
            Err(e) => println!("Inserting movie failed. => {:?}", e),
        };

        response.set(StatusCode::PermanentRedirect)
            .set(Location("/".into()));
        ""
    });
}

但是错误发生了。

src/main.rs:155:18: 155:43 错误:特征 modifier::Modifier<nickel::response::Response<'_, _>>未针对 hyper::header::common::location::Location 类型实现[E0277]src/main.rs:155 .set(位置("/".into()));

终于这样修好了!

            Ok(v) => {
                println!("Inserting movie was Success.");
                response.set(StatusCode::Ok);
            },
            Err(e) => println!("Inserting movie failed. => {:?}", e),
        };

        //response.set(StatusCode::PermanentRedirect)
        //    .set(Location("/".into()));
        //""
        return response.send("");

Answer 1

当前列出的代码没有任何意义。您的路由处理程序没有返回任何内容:

match ... {
    Ok(v) => println!("Inserting movie was Success."),
    Err(e) => println!("Inserting movie failed. => {:?}", e),
};

因为数据库和前端框架都不重要，所以你的代码等同于:

#[macro_use]
extern crate nickel;

use nickel::{Nickel, HttpRouter};

fn main() {
    let mut server = Nickel::new();

    server.post("/api/movies", middleware! { |request, mut response|
        println!("Hello");
    });

    server.listen("127.0.0.1:6767");
}

如果您从处理程序返回某些内容，则 HTTP 状态代码会从 404 更改为 200。

如果您想重定向到某个地方，您需要明确更改状态代码。 Response::set 的文档刚好有个例子:

server.get("/a", middleware! { |_, mut res|
    res.set(StatusCode::PermanentRedirect)
       .set(Location("http://nickel.rs".into()));

    ""
});

请注意，返回的是一个空字符串，与之前类似。您试图直接返回 Response 类型。