使用Fetch方法通过JavaScript调用Post API遇500错误求助

你的Fetch请求失败主要有三个关键问题：

1. 请求头参数拼写错误 #

Fetch配置里的header应为复数headers，单数写法会导致所有自定义请求头（包括x-api-key、x-clientId等凭证参数）无法被正确发送到服务器，这是凭证无效报错的核心原因。

2. 请求体未转为JSON字符串 #

你直接将JavaScript对象作为body传入，但Content-Type设置为application/json，必须用JSON.stringify()把对象转为JSON格式的字符串，否则服务器无法正确解析请求体，进而触发验证失败。

3. 手动设置错误的Content-Length #

手动指定的Content-Length:344和实际请求体长度严重不符，浏览器会自动计算并设置这个头，手动设置反而会导致请求异常，应删除该参数。

修正后的代码： #

<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <h1>Lorem, ipsum dolor sit amet consectetur adipisicing elit. Totam itaque numquam temporibus neque nemo consectetur debitis! Nisi, enim deleniti. Nostrum, beatae. Consequuntur, cum eaque harum at sunt deserunt recusandae eos.</h1>

    <script>
        // 定义请求体对象
        const requestBody = {
            "Version": "1.1",
            "TranDtls": {
                "TaxSch": "GST",
                "SupTyp": "B2B",
                "RegRev": "Y",
                "EcmGstin": null,
                "IgstOnIntra": "N"
            },
            "DocDtls": {
                "Typ": "INV",
                "No": "DOC/029",
                "Dt": "09/08/2021"
            },
            "SellerDtls": {
                "Gstin": "01AMBPG7773M002",
                "LglNm": "ABC Travels Pvt Ltd",
                "TrdNm": null,
                "Addr1": "5th block, kuvempu layout",
                "Addr2": null,
                "Loc": "Jammu and Kashmir",
                "Pin": 181102, 
                "Stcd": "01",
                "Ph": "9000000000",
                "Em": "abc@gmail.com"
            },
            "BuyerDtls": {
                "Gstin": "29AWGPV7107B1Z1",
                "LglNm": "XYZ company pvt ltd",
                "TrdNm": "XYZ Industries",
                "Pos": "12",
                "Addr1": "7th block, kuvempu layout",
                "Addr2": "kuvempu layout",
                "Loc": "GANDHINAGAR",
                "Pin": 562160,
                "Stcd": "29",
                "Ph": "91111111111",
                "Em": "xyz@yahoo.com"
            },
            "DispDtls": {
                "Nm": "ABC company pvt ltd",
                "Addr1": "7th block, kuvempu layout",
                "Addr2": "kuvempu layout",
                "Loc": "Banagalore",
                "Pin": 562160,
                "Stcd": "29"
            },
            "ShipDtls": {
                "Gstin": "29AWGPV7107B1Z1",
                "LglNm": "CBE company pvt ltd",
                "TrdNm": "kuvempu layout",
                "Addr1": "7th block, kuvempu layout",
                "Addr2": "kuvempu layout",
                "Loc": "Banagalore",
                "Pin": 562160,
                "Stcd": "29"
            },
            "ItemList": [
                {
                    "SlNo": "1",
                    "PrdDesc": "Rice",
                    "IsServc": "N",
                    "HsnCd": "1001",
                    "Barcde": "123456",
                    "Qty": 100.345,
                    "FreeQty": 10,
                    "Unit": "BAG",
                    "UnitPrice": 99.545,
                    "TotAmt": 9988.84,
                    "Discount": 10,
                    "PreTaxVal": 1,
                    "AssAmt": 9978.84,
                    "GstRt": 12.0,
                    "IgstAmt": 1197.46,
                    "CgstAmt": 0,
                    "SgstAmt": 0,
                    "CesRt": 5,
                    "CesAmt": 498.94,
                    "CesNonAdvlAmt": 10,
                    "StateCesRt": 12,
                    "StateCesAmt": 1197.46,
                    "StateCesNonAdvlAmt": 5,
                    "OthChrg": 10,
                    "TotItemVal": 12897.7,
                    "OrdLineRef": "3256",
                    "OrgCntry": "AG",
                    "PrdSlNo": "12345",
                    "BchDtls": {
                        "Nm": "123456",
                        "ExpDt": "01/08/2021",
                        "WrDt": "01/09/2021"
                    },
                    "AttribDtls": [
                        {
                            "Nm": "Rice",
                            "Val": "10000"
                        }
                    ]
                }
            ],
            "ValDtls": {
                "AssVal": 9978.84,
                "CgstVal": 0,
                "SgstVal": 0,
                "IgstVal": 1197.46,
                "CesVal": 508.94,
                "StCesVal": 1202.46,
                "Discount": 10,
                "OthChrg": 20,
                "RndOffAmt": 0.3,
                "TotInvVal": 12908,
                "TotInvValFc": 12897.7
            },
            "PayDtls": {
                "Nm": "ABCDE",
                "AccDet": "5697389713210",
                "Mode": "Cash",
                "FinInsBr": "SBIN11000",
                "PayTerm": "100",
                "PayInstr": "Gift",
                "CrTrn": "test",
                "DirDr": "test",
                "CrDay": 100,
                "PaidAmt": 10000,
                "PaymtDue": 5000
            },
            "RefDtls": {
                "InvRm": "TEST",
                "DocPerdDtls": {
                    "InvStDt": "01/08/2021",
                    "InvEndDt": "01/09/2021"
                },
                "PrecDocDtls": [
                    {
                        "InvNo": "DOC/004",
                        "InvDt": "01/08/2021",
                        "OthRefNo": "123456"
                    }
                ],
                "ContrDtls": [
                    {
                        "RecAdvRefr": "Doc/005",
                        "RecAdvDt": "01/08/2021",
                        "TendRefr": "Abc001",
                        "ContrRefr": "Co123",
                        "ExtRefr": "Yo456",
                        "ProjRefr": "Doc-457",
                        "PORefr": "Doc-790",
                        "PORefDt": "01/08/2021"
                    }
                ]
            },
            "AddlDocDtls": [
                {
                    "Url": "https://einv-apisandbox.nic.in",
                    "Docs": "Test Doc",
                    "Info": "Document Test"
                }
            ],
            "ExpDtls": {
                "ShipBNo": "A-248",
                "ShipBDt": "01/08/2021",
                "Port": "INABG1",
                "RefClm": "N",
                "ForCur": "AED",
                "CntCode": "AE",
                "ExpDuty": null
            },
            "EwbDtls": {
                "TransId": "12AWGPV7107B1Z1",
                "TransName": "XYZ EXPORTS",
                "Distance": 100,
                "TransDocNo": "DOC03",
                "VehNo": "ka123456",
                "VehType": "R",
                "TransMode": "1"
            }
        };

        // 发送Fetch请求
        const response = fetch('https://einvoice.pos.bharuwa.com:6015/api/generateeinvoice', {
            method: "POST", 
            mode: "cors",
            headers: {
                "Content-Type": "application/json",
                "x-api-key": "C4789E11-555B-4CC7-9A69-BC1F35B8659E",
                "x-clientId": "C4789E11-555B-4CC7-9A69-BC1F35B8659E",
                "x-api-secret": "44461e58-7ab3-4cf7-b06e-9b68893e4902"
            },
            body: JSON.stringify(requestBody)
        });
    </script>
</body>
</html>

内容的提问来源于stack exchange，提问作者romesh