PHP cURL调用API报HTTP 411错误：请求需分块或含Content-Length

问题分析 #

HTTP 411错误意味着服务器要求请求必须包含Content-Length头，或是使用分块编码传输数据。Postman会自动处理请求头的生成（包括Content-Length），但你的PHP cURL代码存在两个核心问题导致报错：

• 使用CURLOPT_CUSTOMREQUEST => 'POST'会绕过cURL内置的POST请求处理逻辑，导致cURL不会自动计算并添加Content-Length头
• 手动添加Content-Length时，可能存在计算方式错误（比如未正确计算JSON字符串的字节长度）

解决方案 #

方案1：让cURL自动处理请求头（推荐） #

移除CURLOPT_CUSTOMREQUEST，改用CURLOPT_POST => true，同时通过数组转JSON的方式生成请求数据（避免手动编写JSON的语法错误）。cURL会自动计算Content-Length并添加到请求头：

<?php
// 先定义数组，再转成JSON，避免手动写JSON的语法错误
$data = [
    "TokenKey" => "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
    "EmployeeList" => [
        [
            "Example1" => "1",
            "Example2" => "somedata2",
            "Example3" => "somedata3",
            "Example4" => "somedata4",
            "Example5" => "somedata5",
            "Example6" => "somedata6",
            "Example7" => "somedata7",
            "Example8" => "somedata8",
            "Example9" => "somedata9",
            "Example10" => "somedata10",
            "Example11" => "somedata11",
            "Example12" => "somedata12",
            "Example13" => "somedata13",
            "Example14" => "somedata14",
            "Example15" => "somedata15",
            "Example16" => "somedata16",
            "Example17" => "somedata17",
            "Example18" => "somedata18",
            "Example19" => "somedata19",
            "Example20" => "somedata20",
            "Example21" => "somedata21",
            "Example22" => "somedata22",
            "Example23" => "somedata23",
            "Example24" => "somedata24",
            "Example25" => "somedata25",
            "Example26" => "somedata26",
            "Example27" => "somedata27",
            "Example28" => "somedata28",
            "Example29" => "somedata29",
            "Example30" => "somedata30",
            "Example31" => "somedata31",
            "Example32" => null,
            "Example33" => null,
            "Example34" => null,
            "Example35" => "2022-12-06 22:05:22",
            "Example36" => false,
            "Example37" => true
        ]
    ]
];
$jsonData = json_encode($data);

$curl = curl_init();
curl_setopt_array($curl, [
    CURLOPT_URL => 'https://xxx.xxx/xxx/xxx/xxx',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => '',
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 0,
    CURLOPT_FOLLOWLOCATION => true,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_POST => true, // 改用CURLOPT_POST触发自动处理逻辑
    CURLOPT_POSTFIELDS => $jsonData,
    CURLOPT_HTTPHEADER => [
        'Content-Type: application/json'
    ],
]);

$response = curl_exec($curl);
$statusCode = curl_getinfo($curl, CURLINFO_HTTP_CODE); // 新增：获取HTTP状态码
curl_close($curl);

echo $response;
echo "<br>";
echo $statusCode;
?>

方案2：手动添加正确的Content-Length头 #

如果坚持使用CURLOPT_CUSTOMREQUEST，需要手动计算JSON字符串的字节长度，并添加Content-Length请求头：

<?php
$jsonData = '{
    "TokenKey": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
    "EmployeeList": [
        {
            "Example1": "1",
            "Example2": "somedata2",
            "Example3": "somedata3",
            "Example4": "somedata4",
            "Example5": "somedata5",
            "Example6": "somedata6",
            "Example7": "somedata7",
            "Example8": "somedata8",
            "Example9": "somedata9",
            "Example10": "somedata10",
            "Example11": "somedata11",
            "Example12": "somedata12",
            "Example13": "somedata13",
            "Example14": "somedata14",
            "Example15": "somedata15",
            "Example16": "somedata16",
            "Example17": "somedata17",
            "Example18": "somedata18",
            "Example19": "somedata19",
            "Example20": "somedata20",
            "Example21": "somedata21",
            "Example22": "somedata22",
            "Example23": "somedata23",
            "Example24": "somedata24",
            "Example25": "somedata25",
            "Example26": "somedata26",
            "Example27": "somedata27",
            "Example28": "somedata28",
            "Example29": "somedata29",
            "Example30": "somedata30",
            "Example31": "somedata31",
            "Example32": null,
            "Example33": null,
            "Example34": null,
            "Example35": "2022-12-06 22:05:22",
            "Example36": false,
            "Example37": true
        }
    ]
}';

$curl = curl_init();
curl_setopt_array($curl, [
    CURLOPT_URL => 'https://xxx.xxx/xxx/xxx/xxx',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => '',
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 0,
    CURLOPT_FOLLOWLOCATION => true,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_POSTFIELDS => $jsonData,
    CURLOPT_HTTPHEADER => [
        'Content-Type: application/json',
        'Content-Length: ' . strlen($jsonData) // 计算JSON字符串的字节长度
    ],
]);

$response = curl_exec($curl);
$statusCode = curl_getinfo($curl, CURLINFO_HTTP_CODE); // 新增：获取HTTP状态码
curl_close($curl);

echo $response;
echo "<br>";
echo $statusCode;
?>

关键注意点 #

• 用json_encode生成JSON比手动编写更可靠，能避免逗号、引号遗漏等语法错误
• strlen计算的是字符串的字节数，适配json_encode默认输出的UTF-8编码JSON
• 原代码中$statusCode未定义，需调用curl_getinfo才能获取HTTP状态码

内容的提问来源于stack exchange，提问作者isthemi