spring boot获取request

1. Controller中

1.1 通过静态方法获取

HttpServletRequest request = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();

但我在使用过程中发现遇到了一个警告

Method invocation 'getRequest' may produce 'java.lang.NullPointerException' less... (Ctrl+F1)
Inspection info: This inspection analyzes method control and data flow to report possible conditions that are always true or false, expressions whose value is statically proven to be constant, and situations that can lead to nullability contract violations.
Variables, method parameters and return values marked as @Nullable or @NotNull are treated as nullable (or not-null, respectively) and used during the analysis to check nullability contracts, e.g. report NullPointerException (NPE) errors that might be produced.
More complex contracts can be defined using @Contract annotation, for example:
@Contract(", null -> null") — method returns null if its second argument is null @Contract(", null -> null; _, !null -> !null") — method returns null if its second argument is null and not-null otherwise @Contract("true -> fail") — a typical assertFalse method which throws an exception if true is passed to it
The inspection can be configured to use custom @Nullable
@NotNull annotations (by default the ones from annotations.jar will be used)

如此使用可能会造成空指针异常，所以建议添加Objects.requireNonNull，如果为空，抛出异常。

HttpServletRequest request = ((ServletRequestAttributes) Objects.requireNonNull(RequestContextHolder.getRequestAttributes())).getRequest();

附Objects.requireNonNull源码

public static <T> T requireNonNull(T obj) {
        if (obj == null)
            throw new NullPointerException();
        return obj;
    }

1.2 通过参数直接获取

在参数上添加后，springboot会帮你绑定，之后可以直接使用

@GetMapping(value = "")
public String center(HttpServletRequest request,HttpServletResponse response) {
    //...
}

1.3 自动注入

通过@Autowired自动注入，这样就不用每个方法都写了

@Autowired
private HttpServletRequest request;

@Autowired
private HttpServletResponse response;

@GetMapping(value = "")
public String center() {
    //...
}

2.controller以外部分

见1.1

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