Java AWS lambda:格式错误的lambda代理响应

当Lambda坐在API网关后面时，这是一个典型的问题。我在谷歌上搜索了几乎所有的帖子，但仍然不知道为什么失败

我已经阅读了关于响应应该是什么样子的说明
它正在寻找

{
    "isBase64Encoded": true|false,
    "statusCode": httpStatusCode,
    "headers": { "headerName": "headerValue", ... },
    "multiValueHeaders": { "headerName": ["headerValue", "headerValue2", ...], ... },
    "body": "..."
}

这是API网关控制台中的测试日志（我已仔细检查，确保字段名称完全相同）

有人能帮忙吗

编辑 我已经从响应中删除了“body”，但仍然得到相同的错误。以下是实际日志

Thu Mar 19 23:29:54 UTC 2020 : Received response. Status: 200, Integration latency: 24 ms
Thu Mar 19 23:29:54 UTC 2020 : Endpoint response headers: {Date=Thu, 19 Mar 2020 23:29:54 GMT, Content-Type=application/json, Content-Length=48, Connection=keep-alive, x-amzn-RequestId=f2c2c752-a5e0-45e4-9ff0-d91826b51c7b, x-amzn-Remapped-Content-Length=0, X-Amz-Executed-Version=$LATEST, X-Amzn-Trace-Id=root=1-5e740072-46cee9045a56e04b8023816d;sampled=0}
Thu Mar 19 23:29:54 UTC 2020 : Endpoint response body before transformations: "{\"statusCode\":200,\"isBase64Encoded\":false}"
Thu Mar 19 23:29:54 UTC 2020 : Execution failed due to configuration error: Malformed Lambda proxy response
Thu Mar 19 23:29:54 UTC 2020 : Method completed with status: 502

java应用程序和lambda中的实际JSON响应

{"statusCode":200,"isBase64Encoded":false}

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在与Node.js示例进行比较之后，似乎这与处理程序有关

使用请求处理程序时，响应是字符串

public class MyLambda implements RequestHandler<Object, String> {
    @Override
    public String handleRequest(Object input, Context context) {

将其更改为RequestStreamHandler，错误消失

public class APIgatewayTest implements RequestStreamHandler {
    @Override
    public void handleRequest(InputStream input, OutputStream output, Context context) throws IOException {

从API网关，响应如下

Thu Apr 09 09:13:08 UTC 2020 : Endpoint response body before transformations: {"statusCode":200,"body":"\"Hello from Lambda!\""}
Thu Apr 09 09:13:08 UTC 2020 : Method response body after transformations: "Hello from Lambda!"

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生成此响应的代码是什么？@Marcin，它是一个java类。我假设它没有影响，因为API网关与Lambda对话，试图解析Lambda的HTTP响应？这里的结果格式是什么？尝试从您的响应中删除body，以缩小它与结果的关系，并对其进行测试。@SurajBhatia，我在做一个简单的测试，我显示的日志是实际的日志，这意味着body的内容是一个字符串“RESULT”，您的实际JSON响应是什么样子的？

public class APIgatewayTest implements RequestStreamHandler {
    @Override
    public void handleRequest(InputStream input, OutputStream output, Context context) throws IOException {

Thu Apr 09 09:13:08 UTC 2020 : Endpoint response body before transformations: {"statusCode":200,"body":"\"Hello from Lambda!\""}
Thu Apr 09 09:13:08 UTC 2020 : Method response body after transformations: "Hello from Lambda!"