第 3 章 · 请求与响应

POST /api/comment/add?from=detail HTTP/1.1
Host: 127.0.0.1:5000
Content-Type: application/json
Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9....
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7)

{"article_id": 1, "content": "好诗！", "parent_id": null}

from flask import Flask, request

app = Flask(__name__)


@app.route("/api/debug/echo", methods=["GET", "POST"])
def echo():
    print("方法：", request.method)
    print("路径：", request.path)
    print("查询参数：", request.args.to_dict())
    print("客户端：", request.remote_addr)
    print("浏览器：", request.headers.get("User-Agent"))
    print("内容类型：", request.content_type)
    return "ok"

from flask import Flask, jsonify, request

app = Flask(__name__)
app.json.ensure_ascii = False


@app.route("/api/article/list", methods=["GET"])
def article_list():
    # 取参数：名字对接口文档，没传就用默认值
    page = request.args.get("page", 1, type=int)
    page_size = request.args.get("page_size", 10, type=int)
    category_id = request.args.get("category_id", type=int)   # 不传就是 None
    keyword = request.args.get("keyword", "").strip()
    order_by = request.args.get("order_by", "latest")

    # 顺手做一层保护：防止前端传 page=0 或 page_size=99999
    page = max(page, 1)
    page_size = min(max(page_size, 1), 50)

    return jsonify({
        "code": 200,
        "msg": "success",
        "data": {
            "list": [],
            "total": 0,
            "page": page,
            "page_size": page_size,
            "category_id": category_id,
            "keyword": keyword,
            "order_by": order_by,
        },
    })

from flask import Flask, jsonify, request

app = Flask(__name__)
app.json.ensure_ascii = False


@app.route("/api/comment/add", methods=["POST"])
def comment_add():
    # ① 读 JSON 体。silent=True 表示：体不是合法 JSON 时返回 None，而不是直接抛 415
    data = request.get_json(silent=True)
    if not data:
        return jsonify({"code": 400, "msg": "请求体必须是合法 JSON", "data": None})

    # ② 取字段。用 .get()，不要用 data["xxx"]，缺字段时不会崩
    article_id = data.get("article_id")
    content = (data.get("content") or "").strip()
    parent_id = data.get("parent_id")          # 为空表示直接评论作品

    # ③ 校验必填
    if not article_id:
        return jsonify({"code": 400, "msg": "缺少参数：article_id", "data": None})
    if not content:
        return jsonify({"code": 400, "msg": "书评内容不能为空", "data": None})
    if len(content) > 1000:
        return jsonify({"code": 400, "msg": "书评最多 1000 字", "data": None})

    # ④ 校验过了才进业务（第 6 章这里会插入 comment 表）
    return jsonify({
        "code": 200,
        "msg": "发表成功",
        "data": {"comment_id": 9, "article_id": article_id,
                 "content": content, "parent_id": parent_id},
    })


# 表单格式（含文件上传）用 request.form / request.files，例如第 9 章的上传头像
@app.route("/api/user/avatar", methods=["POST"])
def upload_avatar():
    nickname = request.form.get("nickname", "")
    file = request.files.get("file")           # 文件对象
    if file is None:
        return jsonify({"code": 400, "msg": "请选择要上传的图片", "data": None})
    return jsonify({"code": 200, "msg": "上传成功",
                    "data": {"filename": file.filename, "nickname": nickname}})

from flask import Flask, jsonify, request

app = Flask(__name__)
app.json.ensure_ascii = False


@app.route("/api/user/profile", methods=["GET", "PUT"])
def user_profile():
    # ① 从请求头取 Authorization，形如 "Bearer eyJhbGciOi..."
    auth = request.headers.get("Authorization", "")
    if not auth.startswith("Bearer "):
        # 业务码 401：前端拦截器看到它会清 token 并跳登录页
        return jsonify({"code": 401, "msg": "请先登录", "data": None})

    token = auth[7:]          # 去掉 "Bearer " 这 7 个字符，剩下的才是 token
    # 第 8 章：这里会用 PyJWT 验签并解出 user_id，本章先不校验

    if request.method == "PUT":
        data = request.get_json(silent=True) or {}
        nickname = (data.get("nickname") or "").strip()
        if not nickname:
            return jsonify({"code": 400, "msg": "昵称不能为空", "data": None})
        return jsonify({"code": 200, "msg": "修改成功", "data": {"nickname": nickname}})

    # GET：返回个人信息
    return jsonify({
        "code": 200,
        "msg": "success",
        "data": {
            "id": 3,
            "username": "zhangsan",
            "nickname": "张三",
            "email": "zhangsan@example.com",
            "avatar": "/static/upload/avatar/3.png",
            "intro": "爱读唐诗",
            "gender": 1,
            "created_at": "2026-10-12 10:30:00",
        },
    })

from flask import Flask, jsonify, make_response

app = Flask(__name__)
app.json.ensure_ascii = False


# ① 返回字符串：最原始，Content-Type 是 text/html
@app.route("/ping")
def ping():
    return "pong"


# ② 返回 JSON：接口的主力写法
@app.route("/api/version")
def version():
    return jsonify({"code": 200, "msg": "success", "data": {"version": "1.0"}})


# ③ 返回元组：(内容, 状态码) 或 (内容, 状态码, 响应头)
@app.route("/api/banner/detail")
def banner_detail():
    # 记录不存在时返回 HTTP 404；业务码和 HTTP 码不必一样（见下一节说明）
    return jsonify({"code": 404, "msg": "轮播图不存在", "data": None}), 404, {"X-Tip": "banner"}


# ④ make_response：需要精调响应对象时用
@app.route("/api/health")
def health():
    resp = make_response(jsonify({"code": 200, "msg": "success",
                                  "data": {"status": "ok"}}))
    resp.status_code = 200
    resp.headers["X-Server"] = "hiflask"
    resp.set_cookie("visited", "1", max_age=3600)   # 写 Cookie
    return resp

from flask import jsonify


def ok(data=None, msg="success"):
    """成功：code 固定 200"""
    return jsonify({"code": 200, "msg": msg, "data": data})


def fail(code=400, msg="参数错误"):
    """失败：data 固定为 None，msg 直接给用户看"""
    return jsonify({"code": code, "msg": msg, "data": None})

from flask import Flask, request
from utils.response import ok, fail      # 上面那两个小函数

app = Flask(__name__)
app.json.ensure_ascii = False


@app.route("/api/comment/add", methods=["POST"])
def comment_add():
    data = request.get_json(silent=True)
    if not data:
        return fail(400, "请求体必须是合法 JSON")

    article_id = data.get("article_id")
    content = (data.get("content") or "").strip()

    if not article_id:
        return fail(400, "缺少参数：article_id")
    if not content:
        return fail(400, "书评内容不能为空")
    if len(content) > 1000:
        return fail(400, "书评最多 1000 字")

    # 第 6 章这里会插入 comment 表，拿到真实的自增主键
    return ok({"comment_id": 9}, "发表成功")


@app.route("/api/comment/<int:cid>", methods=["DELETE"])
def comment_delete(cid):
    # 未登录 / token 失效 → 401，前端拦截器收到就跳登录页
    return fail(401, "登录已过期，请重新登录")

# ① 查询参数：作品列表，第 1 页、每页 2 条、只看唐诗
curl -s "http://127.0.0.1:5000/api/article/list?page=1&page_size=2&category_id=1" \
  | python -m json.tool --indent 2

# ② JSON 体：发表一条书评（POST 一定要指定 Content-Type）
curl -s -X POST http://127.0.0.1:5000/api/comment/add \
  -H "Content-Type: application/json" \
  -d '{"article_id": 1, "content": "短短二十字，写尽思乡之情。"}' \
  | python -m json.tool --indent 2

# ③ 请求头 token：个人信息（需要登录）
curl -s http://127.0.0.1:5000/api/user/profile \
  -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...." \
  | python -m json.tool --indent 2