如何优雅的写 Controller 层代码？
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瞧瞧，人家这后端API接口写得，那叫一个巴适~，再看看我的，像坨屎！
实战总结！18种接口优化方案的总结
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7种方式，教你提升 SpringBoot 项目的吞吐量
Spring Boot 程序优化的 14 个小妙招！

统一返回格式

定义一个业务CODE枚举类

public enum ResultCodeEnum {SUCCESS(1, "成功"),//参数错误ILLEGAL_PARAMETER(10001, "非法参数");private Integer code;private String msg;ResultCodeEnum(Integer code, String msg) {this.code = code;this.msg = msg;}public Integer getCode() {return code;}public String getMsg() {return msg;}
}

定义统一返回类

public class R implements Serializable {private T data;private Integer code;private String msg;public static  R ok(T data) {R r = new R<>();r.setData(data);return r;}public static  R ok(ResultCodeEnum codeEnum, T data) {R r = new R<>();r.setData(data);r.setCode(codeEnum.getCode());r.setMsg(codeEnum.getMsg());return r;}public static  R fail(Integer code, String msg) {R r = new R<>();r.setCode(code);r.setMsg(msg);return r;}public static  R fail(ResultCodeEnum codeEnum) {R r = new R<>();r.setCode(codeEnum.getCode());r.setMsg(codeEnum.getMsg());return r;}//省略部分代码
}

定义一个封装注解

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Documented
public @interface Result {
}

ResponseBodyAdvice

Allows customizing the response after the execution of an @ResponseBody or a ResponseEntity controller method but before the body is written with an HttpMessageConverter.

两种思路，一种是beforeBodyWrite，另一种是 String

全局异常处理

@RestControllerAdvice

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@ControllerAdvice
@ResponseBody
public @interface RestControllerAdvice {@AliasFor(annotation = ControllerAdvice.class)String[] value() default {};@AliasFor(annotation = ControllerAdvice.class)String[] basePackages() default {};@AliasFor(annotation = ControllerAdvice.class)Class[] basePackageClasses() default {};@AliasFor(annotation = ControllerAdvice.class)Class[] assignableTypes() default {};@AliasFor(annotation = ControllerAdvice.class)Class[] annotations() default {};
}

@ExceptionHandler

//修饰方法
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ExceptionHandler {//接收一个Throwable子类的class数组Class[] value() default {};
}

    @ExceptionHandler(MethodArgumentNotValidException.class)

参数校验

性能优化