基于Spring框架的记录操做日志

HTTP 接口调用操做日志

对于一些HTTP API接口，有时候须要记录日志，了解什么用户在什么时间调用了什么接口，调用的参数是什么，返回的结果是什么。可是，又不能侵入业务代码逻辑。

http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/servlet/mvc/method/annotation/ResponseBodyAdvice.html

在什么地方记录？

首先想到的时候使用Filter，可是发现要获取response中的body内容，太麻烦，而ResponseBodyAdvice这个接口偏偏能够知足咱们的需求。

/**
 * 容许兹定于response内容，只能在@ResponseBody或者@responseEntity注解的controller方法
 * 有用。改方法会在把body内容经过HttpMessaheConverter写入前调用
 * 
 * 实现该接口并经过 @ControllerAdvice来注册
 *
 * @since 4.1
 */
public interface ResponseBodyAdvice<T> {

   /**
    * 当返回true的时候会调用beforeBodyWrite方法，不然不会
    */
   boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType);

   /**
    * {@code HttpMessageConverter}选择后和写入前调用
    * @param body the body to be written
    * @param returnType the return type of the controller method
    * @param selectedContentType the content type selected through content negotiation
    * @param selectedConverterType the converter type selected to write to the response
    * @param request the current request
    * @param response the current response
    * @return the body that was passed in or a modified, possibly new instance
    */
   T beforeBodyWrite(T body, MethodParameter returnType, MediaType selectedContentType,
         Class<? extends HttpMessageConverter<?>> selectedConverterType,
         ServerHttpRequest request, ServerHttpResponse response);

}

怎么进行有选择性的记录

@ResponseBody注解的方法都会调用这个Advice，但并非咱们都须要记录，而且怎么知道body内容是表示成功或者失败了呢

咱们能够经过自定义注解来解决

@Documented
@Target({METHOD})
@Retention(RUNTIME)
public @interface OpLog {

    /**
     * 是否只记录成功的操做，若是为false，result和status和successFlag参数就没用
     *
     * @return
     */
    boolean onlySuccess() default true;

    /**
     * 返回的数据是什么样的类
     *
     * @return
     */
    Class result() default Result.class;

    /**
     * 存储成功的标志
     *
     * @return
     */
    String status() default "state";

    /**
     * 成功标志对应的值
     *
     * @return
     */
    String successFlag() default "success";
}

该注解有4个配置，其中为了知道接口调用时成功仍是失败，就必须知道3个事情

1. body是什么类
2. 该类用什么来字段来存储调用状况
3. 该字段的值为何的时候，就是表示成功

这样，在ResponseBodyAdvice的supports方法，经过判断改方法是否有@Oplog来判断是否须要进行日志写入，而后beforeBodyWrite方法中，生成日志信息，并记录日志，下面是我本身定义类实现ResponseBodyAdvice接口。

@ControllerAdvice
public class OpLogSaveResponseBodyAdvice implements ResponseBodyAdvice<Object> {

    @Autowired
    private LogWriterService logWriterService;

    @Autowired
    ExecutorService logWriterPool = Executors.newFixedThreadPool(2);

    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        OpLog opLog = getOpLog(returnType);
        return opLog != null;
    }


    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        OpLog opLog = getOpLog(returnType);
        if (opLog != null && request instanceof ServletServerHttpRequest) {
            ServletServerHttpRequest servletServerHttpRequest = (ServletServerHttpRequest) request;
            HttpServletRequest httpServletRequest = servletServerHttpRequest.getServletRequest();
            if (body != null && body.getClass() == opLog.result()) {
                logWriterPool.execute(new OpLogWriter(body, opLog, httpServletRequest));
            }
        }
        return body;
    }


    private OpLog getOpLog(MethodParameter returnType) {
        if (returnType != null && returnType.getMethod() != null) {
            return returnType.getMethod().getAnnotation(OpLog.class);
        }
        return null;
    }

    //根据 OpLog中定义的属性，判断是否成功。
    //从 httpServletRequest 中获取相关的信息，生成日志信息
    private OpLogMsg buildMsg(Object body, OpLog opLog, HttpServletRequest httpServletRequest) {
        //从httpServletRequest中获取 username,parameter,url
        String username = BaseUserContext.getCurrentUser(httpServletRequest).getUsername();
        String parameter = JSONObject.toJSONString(httpServletRequest.getParameterMap());
        String url = httpServletRequest.getRequestURI();
        //设置
        OpLogMsg opLogMsg = new OpLogMsg();
        opLogMsg.setUsername(username);
        opLogMsg.setParamter(parameter);
        opLogMsg.setUrl(url);
        opLogMsg.setCreateDate(new Date());

        //获取是否成功，根据OpLog中的相关信息判断
        Class clazz = body.getClass();
        Field[] fields = clazz.getDeclaredFields();
        Field.setAccessible(fields, true);
        //用于判断是否成功的属性
        String flagFieldName = opLog.status();
        //属性的值为successFlag则表示成功
        String successFlag = opLog.successFlag();
        for (int i = 0; i < fields.length; i++) {
            String name = fields[i].getName();
            if (StringUtils.equalsIgnoreCase(name, flagFieldName)) {
                try {
                    if (StringUtils.equals(fields[i].get(body).toString(), successFlag)) {
                        opLogMsg.setSuccess(OpLogMsg.SUCCESS);
                    } else {
                        opLogMsg.setSuccess(OpLogMsg.FAIL);
                    }
                } catch (IllegalAccessException e) {
                    opLogMsg.setSuccess(OpLogMsg.UNKNOWN);
                }
                break;
            }
        }
        return opLogMsg;
    }

    class OpLogWriter implements Runnable {
        Object body;
        OpLog opLog;
        HttpServletRequest httpServletRequest;

        OpLogWriter(Object body, OpLog opLog, HttpServletRequest httpServletRequest) {
            this.body = body;
            this.opLog = opLog;
            this.httpServletRequest = httpServletRequest;
        }

        @Override
        public void run() {
            OpLogMsg opLogMsg = buildMsg(body, opLog, httpServletRequest);
            if(opLog.onlySuccess() && !OpLogMsg.SUCCESS.equals(opLogMsg.getSuccess())){
                return;
            }
            logWriterService.writeOpLog(opLogMsg);
        }
    }
}

注：

1. 为了避免阻塞原有的流程，所以使用一个线程池异步写日志
2. buildMsg的方法能够根据业务须要生成记录信息，这里是记录了调用的用户名（使用的Spring Security框架），调用时间，调用的url，url参数。OpLogMsg做为封装的Entity类

使用方法

通常状况下，咱们HTTP API接口放回的数据格式都是一致的，所以能够做为@OpLog的默认配置，但也支持自定义配置，全部一般状况下只用在须要记录日志的地方增长@OpLog注解就能够了