- 客户端没有执行操作的权限
- 客户端没有访问资源的权限
- 客户端要访问的项目不存在
- 等等 ...

遇到这些情况时，通常要返回 **4XX**（400 至 499）**HTTP 状态码**。

**4XX** 状态码与表示请求成功的 **2XX**（200 至 299） HTTP 状态码类似。

只不过，**4XX** 状态码表示客户端发生的错误。

大家都知道**「404 Not Found」**错误，还有调侃这个错误的笑话吧？

## 使用 `HTTPException`

向客户端返回 HTTP 错误响应，可以使用 `HTTPException`。

### 导入 `HTTPException`

{* ../../docs_src/handling_errors/tutorial001.py hl[1] *}

### 触发 `HTTPException`

// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package tar

import (
	"bytes"
	"fmt"
	"strconv"
	"strings"
	"time"
)

// hasNUL reports whether the NUL character exists within s.
func hasNUL(s string) bool {
	return strings.Contains(s, "\x00")
}

// isASCII reports whether the input is an ASCII C-style string.

## Avertissement

				}
			}
		default:
			bts, err = msgp.Skip(bts)
			if err != nil {
				err = msgp.WrapError(err)
				return
			}
		}
	}
	o = bts
	return
}

// Msgsize returns an upper bound estimate of the number of bytes occupied by the serialized message
func (z *nsScannerOptions) Msgsize() (s int) {
	s = 1 + 3 + msgp.StringPrefixSize + len(z.DiskID) + 2 + msgp.IntSize + 2
	if z.Cache == nil {

				return
			}
		default:
			bts, err = msgp.Skip(bts)
			if err != nil {
				err = msgp.WrapError(err)
				return
			}
		}
	}
	o = bts
	return
}

// Msgsize returns an upper bound estimate of the number of bytes occupied by the serialized message
func (z RStat) Msgsize() (s int) {
	s = 1 + 6 + msgp.Int64Size + 6 + msgp.Int64Size
	return
}

// DecodeMsg implements msgp.Decodable

./mc rm sitea/delissue/hello --insecure

count=$(./mc ls --versions sitea/delissue --insecure | wc -l)

if [ ${count} -ne 3 ]; then
	echo "BUG: expected number of versions to be '3' found ${count}"
	echo "===== DEBUG ====="
	./mc ls --versions sitea/delissue
fi

./mc mb sitea/testbucket

./mc version enable sitea/testbucket

./mc put --quiet README.md sitea/testbucket/file

        fun selectVersionsFrom(minimumSupported: String, allVersions: List<String>): List<String> {
            require(minimumSupported in allVersions) {
                "Minimum supported '$minimumSupported' was not found in available versions: $allVersions"
            }
            val versionsByMinor = allVersions
                .groupBy { it.take(3) } // e.g. 1.9
                .toSortedMap()
            val latests = buildList {

#!/bin/bash -e
#

set -E
set -o pipefail

if [ ! -x "$PWD/minio" ]; then
	echo "minio executable binary not found in current directory"
	exit 1
fi

WORK_DIR="$PWD/.verify-$RANDOM"
MINIO_CONFIG_DIR="$WORK_DIR/.minio"
MINIO=("$PWD/minio" --config-dir "$MINIO_CONFIG_DIR" server)
GOPATH=/tmp/gopath

function start_minio_3_node() {
	for i in $(seq 1 3); do
		rm "${WORK_DIR}/dist-minio-server$i.log"
	done

labels: ["Proposal", "LanguageChange", "LanguageChangeReview"]
title: "proposal: spec: proposal title"


body:
  - type: markdown
    attributes:
      value: |
       ## Our process for evaluating language changes can be found [here](https://go.googlesource.com/proposal/+/refs/heads/master#language-changes)

  - type: dropdown
    id: author-go-experience
    attributes:
      label: "Go Programming Experience"

            Builder builder = builders.get(builderId);
            if (builder == null) {
                throw new BuilderNotFoundException(
                        String.format("The builder requested using id = %s cannot be" + " found", builderId));
            }

            int degreeOfConcurrency = session.getRequest().getDegreeOfConcurrency();
            if (degreeOfConcurrency > 1) {
                logger.info("");