How to Implement Custom Logging with Spring AOP and Annotations

Introduction

When building a Spring project, logging requirements often exceed what simple AOP can capture; basic logs may only record table names or operation types. To store richer information, a custom annotation is introduced, allowing developers to embed desired log details and retrieve them through pointcuts for database insertion.

Spring AOP Basics

Reference: https://blog.csdn.net/yjt520557/article/details/84833508

Key terminology:

Aspect : Implemented via a regular class annotated with @Aspect (AspectJ style) or a generic class.

Joinpoint : Represents a method execution point.

Advice : Action executed at a specific joinpoint (e.g., @Around, @Before, @After).

Pointcut : Defines one or more methods that trigger advice; Spring uses AspectJ pointcut syntax by default.

Advice Types

@Before : Executes before a joinpoint; cannot prevent execution unless an exception is thrown.

@AfterReturning : Executes after successful completion of a joinpoint.

@AfterThrowing : Executes when a method throws an exception.

@After : Executes after a joinpoint regardless of outcome.

@Around : Wraps a joinpoint, allowing custom behavior before and after method invocation, and can control whether the original method proceeds.

Spring AOP Configuration Styles

XML style: Declares AOP support in XML.

AspectJ style: Uses annotation‑based configuration.

Creating a Custom Annotation

Define an annotation to hold log description and table name:

package com.ywj.log;
import java.lang.annotation.*;
/**
 * @interface SystemCrmlog
 * Custom annotation for AOP logging
 */
@Target({ElementType.PARAMETER, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface SystemCrmlog {
    String description() default "";
    String tableName() default "";
}

Aspect Class – Extracting Annotation Data

The aspect intercepts methods annotated with @SystemCrmlog, gathers request, user, and method details, builds a CrmLogMessage object, and persists it via Sys_logDao:

package com.ywj.log;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.*;
import org.springframework.stereotype.Component;
import javax.servlet.http.HttpServletRequest;
import java.text.SimpleDateFormat;
import java.util.*;

@Aspect
@Component
public class SystemLogAspect {
    @Pointcut("@annotation(com.ywj.log.SystemCrmlog)")
    public void crmAspect() {}

    @AfterThrowing(value="crmAspect()", throwing="ex")
    public void afterThrowingMethod(JoinPoint joinPoint, Exception ex) throws Exception {
        HttpServletRequest request = getHttpServletRequest();
        WebUtil webUtil = new WebUtil();
        Map<String, Object> user = webUtil.getUser(request);
        CrmLogMessage log = new CrmLogMessage();
        String context = getServiceMthodDescription(joinPoint);
        String usr_name = "";
        String rolename = "";
        if (user != null) {
            usr_name = user.get("usr_name").toString();
            rolename = user.get("rolename").toString();
        }
        log.setUserName(usr_name);
        log.setUserRole(rolename);
        log.setContent(usr_name + context);
        log.setRemarks(getServiceMthodParams(joinPoint));
        log.setTableName(getServiceMthodTableName(joinPoint));
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        log.setDateTime(sdf.format(new Date()));
        log.setIp(request.getRemoteAddr());
        log.setRequestUrl(request.getRequestURI());
        log.setResult("执行失败");
        log.setExString(ex.getMessage());
        new Sys_logDao().addSys_log(log);
    }

    @AfterReturning(value="crmAspect()", returning="returnValue")
    public void doCrmLog(JoinPoint joinPoint, Object returnValue) throws Exception {
        HttpServletRequest request = getHttpServletRequest();
        WebUtil webUtil = new WebUtil();
        Map<String, Object> user = webUtil.getUser(request);
        CrmLogMessage log = new CrmLogMessage();
        String context = getServiceMthodDescription(joinPoint);
        String usr_name = "";
        String rolename = "";
        if (user != null) {
            usr_name = user.get("usr_name").toString();
            rolename = user.get("rolename").toString();
        }
        log.setUserName(usr_name);
        log.setUserRole(rolename);
        log.setContent(usr_name + context);
        log.setRemarks(getServiceMthodParams(joinPoint));
        log.setTableName(getServiceMthodTableName(joinPoint));
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        log.setDateTime(sdf.format(new Date()));
        log.setIp(request.getRemoteAddr());
        log.setRequestUrl(request.getRequestURI());
        // Determine result based on returnValue type
        if (returnValue != null) {
            if (returnValue instanceof List) {
                log.setResult(((List<?>) returnValue).size() > 0 ? "执行成功" : "执行成功");
            } else if (returnValue instanceof Boolean) {
                log.setResult(((Boolean) returnValue) ? "执行成功" : "执行失败");
            } else if (returnValue instanceof Integer) {
                log.setResult(((Integer) returnValue) > 0 ? "执行成功" : "执行失败");
            } else {
                log.setResult("执行成功");
            }
        }
        new Sys_logDao().addSys_log(log);
    }

    private String getServiceMthodDescription(JoinPoint joinPoint) throws Exception {
        String targetName = joinPoint.getTarget().getClass().getName();
        String methodName = joinPoint.getSignature().getName();
        Object[] arguments = joinPoint.getArgs();
        Class<?> targetClass = Class.forName(targetName);
        for (Method method : targetClass.getMethods()) {
            if (method.getName().equals(methodName) && method.getParameterTypes().length == arguments.length) {
                return method.getAnnotation(SystemCrmlog.class).description();
            }
        }
        return "";
    }

    private String getServiceMthodTableName(JoinPoint joinPoint) throws Exception {
        String targetName = joinPoint.getTarget().getClass().getName();
        String methodName = joinPoint.getSignature().getName();
        Object[] arguments = joinPoint.getArgs();
        Class<?> targetClass = Class.forName(targetName);
        for (Method method : targetClass.getMethods()) {
            if (method.getName().equals(methodName) && method.getParameterTypes().length == arguments.length) {
                return method.getAnnotation(SystemCrmlog.class).tableName();
            }
        }
        return "";
    }

    private String getServiceMthodParams(JoinPoint joinPoint) throws Exception {
        Object[] arguments = joinPoint.getArgs();
        return new com.fasterxml.jackson.databind.ObjectMapper().writeValueAsString(arguments);
    }

    public HttpServletRequest getHttpServletRequest() {
        return ((org.springframework.web.context.request.ServletRequestAttributes)org.springframework.web.context.request.RequestContextHolder.getRequestAttributes()).getRequest();
    }
}

Log Entity Class

Represents a database record for each logged operation:

package com.ywj.log;
public class CrmLogMessage {
    private Integer logid;
    private String UserName;
    private String UserRole;
    private String Content;
    private String Remarks;
    private String TableName;
    private String DateTime;
    private String resultValue;
    private String ip;
    private String requestUrl;
    private String result;
    private String ExString;
    // getters, setters, constructors, toString omitted for brevity
}

Utility Class for Session User

package com.ywj.log;
import javax.servlet.http.HttpServletRequest;
import java.util.Map;
public class WebUtil {
    public Map<String, Object> getUser(HttpServletRequest request) {
        if (request == null) return null;
        Object user = request.getSession().getAttribute(Constans.USER_KEY);
        return (Map<String, Object>) user;
    }
}

Spring Configuration

<aop:aspectj-autoproxy proxy-target-class="true"/>
<context:component-scan base-package="com.ywj.log"/>
<context:component-scan base-package="com.*.*.biz.impl"/>

Usage Example

Annotate any service method that requires logging:

@SystemCrmlog(description = "Performed login operation", tableName = Constans.USER_TABLENAME)
public void login(...) { ... }

After execution, a record similar to the following is stored in the database: