HTTP Error 400 Bad request 问题分析解决

1.问题描述：

前端保存老是报错HTTP ERROR 400 Bad Request。经过异常分析得出是前端传参导致的后端框架的验证拦截，包的错误。

2.异常信息如下：

{"timestamp":1545873831082,"status":400,"error":"Bad Request","exception":"org.springframework.validation.BindException","errors":[{"codes":["typeMismatch.capitalInvestmentParam.investmentEnsureMoney","typeMismatch.investmentEnsureMoney","typeMismatch.java.math.BigDecimal","typeMismatch"],"arguments":[{"codes":["capitalInvestmentParam.investmentEnsureMoney","investmentEnsureMoney"],"arguments":null,"defaultMessage":"investmentEnsureMoney","code":"investmentEnsureMoney"}],"defaultMessage":"Failed to convert property value of type 'java.lang.String' to required type 'java.math.BigDecimal' for property 'investmentEnsureMoney'; nested exception is java.lang.NumberFormatException","objectName":"capitalInvestmentParam","field":"investmentEnsureMoney","rejectedValue":"null","bindingFailure":true,"code":"typeMismatch"},{"codes":["typeMismatch.capitalInvestmentParam.investmentEnsureMoneyInterest","typeMismatch.investmentEnsureMoneyInterest","typeMismatch.java.math.BigDecimal","typeMismatch"],"arguments":[{"codes":["capitalInvestmentParam.investmentEnsureMoneyInterest","investmentEnsureMoneyInterest"],"arguments":null,"defaultMessage":"investmentEnsureMoneyInterest","code":"investmentEnsureMoneyInterest"}],"defaultMessage":"Failed to convert property value of type 'java.lang.String' to required type 'java.math.BigDecimal' for property 'investmentEnsureMoneyInterest'; nested exception is java.lang.NumberFormatException","objectName":"capitalInvestmentParam","field":"investmentEnsureMoneyInterest","rejectedValue":"null","bindingFailure":true,"code":"typeMismatch"}],"message":"Validation failed for object='capitalInvestmentParam'. Error count: 2","path":"/rayProjectCapitalInvestment/insertStockPowerInvestment"}

3.分析异常信息：

Failed to convert property value of type ‘java.lang.String’ to required type ‘java.math.BigDecimal’ for property ‘investmentEnsureMoneyInterest’; nested exception is java.lang.NumberFormatException

看一下前端传入的参数如下图：


前端的参数应该是金额要么是空值，结果传输的时候传一个null，后台接收的时候是用bigDecimal 参数类型导致参数异常，报的400错误问题。

4.总结：

经过分析得出400错误code：数据框架的验证拦截前端传入的参数异常，参数类型异常，一般情况下出现400，都是前端传入的参数异常。