开发笔记

一、工具类（服务器返回数据） 2019/1/11

//保证序列化JSON的时候，如果对象为null，key也会消失
@JsonSerialize(include = JsonSerialize.Inclusion.NON_NULL)
public class ServerResponse<T> implements Serializable {
    private int status;
    private String msg;
    private T data;

    private ServerResponse(int status) {
        this.status = status;
    }

    private ServerResponse(int status, String msg, T data) {
        this.status = status;
        this.msg = msg;
        this.data = data;
    }

    private ServerResponse(int status, String msg) {
        this.status = status;
        this.msg = msg;
    }

    private ServerResponse(int status, T data) {
        this.status = status;
        this.data = data;
    }

    /**
     * 如果返回0，代表响应成功
     * @return
     */
    @JsonIgnore
    public boolean isSuccess(){
        return this.status == ResponseCode.SUCCESS.getCode();
    }

    public int getStatus() {
        return status;
    }

    public String getMsg() {
        return msg;
    }

    public T getData() {
        return data;
    }

    public static <T> ServerResponse<T> createBySuccess(){
        return new ServerResponse<T>(ResponseCode.SUCCESS.getCode());
    }

    public static <T> ServerResponse<T> createBySuccessMsg(String msg){
        return new ServerResponse<T>(ResponseCode.SUCCESS.getCode(),msg);
    }

    public static <T> ServerResponse<T> createBySuccess(T data){
        return new ServerResponse<T>(ResponseCode.SUCCESS.getCode(),data);
    }

    public static <T> ServerResponse<T> createBySuccess(String msg, T data){
        return new ServerResponse<T>(ResponseCode.SUCCESS.getCode(),msg,data);
    }

    public static <T> ServerResponse<T> createByError(){
        return new ServerResponse<T>(ResponseCode.ERROR.getCode()
                ,ResponseCode.ERROR.getDesc());
    }

    public static <T> ServerResponse<T> createByError(String errorMessage){
        return new ServerResponse<T>(ResponseCode.ERROR.getCode(),errorMessage);
    }

    public static <T> ServerResponse<T> createByErrorCodeMessage(int errorCode,String errorMessage){
        return new ServerResponse<T>(errorCode,errorMessage);
    }
}

使用：

try {
            Data data = service.method(param);
            return ServerResponse.createBySuccess(data);
        }catch (Exception e){
            LOGGER.error(ExceptionUtil.getMessage(e));
            return ServerResponse.createByError("数据获取失败!");
        }

二、工具类（通过spring aop 处理所有@RequestMapping注解方法的异常） 2019/1/11

package com.data.ops;

import com.alibaba.fastjson.JSON;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

@Aspect
@Component
public class WebExceptionAspect {
    private static final Logger logger = LoggerFactory.getLogger(WebExceptionAspect.class);

    //凡是注解了RequestMapping的方法都被拦截
    @Pointcut("@annotation(org.springframework.web.bind.annotation.RequestMapping)")
    private void webPointcut() {
    }

    /**
     * 拦截web层异常，记录异常日志，并返回友好信息到前端 目前只拦截Exception，是否要拦截Error需再做考虑     
　　　*     
　　　* @param e     
　　　*  异常对象
     */
    @AfterThrowing(pointcut = "webPointcut()", throwing = "e")
    public void handleThrowing(Exception e) {
        e.printStackTrace();
        logger.error("发现异常！" + e.getMessage());
        logger.error(JSON.toJSONString(e.getStackTrace()));
        //这里输入友好性信息
        writeContent("出现异常");
    }
    /**     
　　　* 将内容输出到浏览器     
　　　*     
　　　* @param content     
　　　*        输出内容     
　　　*/
    private void writeContent(String content) {
        HttpServletResponse response = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getResponse();
        response.reset();
        response.setCharacterEncoding("UTF-8");
        response.setHeader("Content-Type", "text/plain;charset=UTF-8");
        response.setHeader("icop-content-type", "exception");
        PrintWriter writer = null;
        try {
            writer = response.getWriter();
        } catch (IOException e) {
            e.printStackTrace();
        }
        writer.print(content);
        writer.flush();
        writer.close();
    }}

 开发中问题：

1、spring boot项目请求不到图片资源

最快解决方案，添加Thymeleaf 模板引擎依赖。

<dependency>
　　<groupId>org.springframework.boot</groupId>
　　<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

2、IDEA按键错乱问题（IDEA VIM编辑模式）

勾掉 菜单栏-Tools-Vim Emulator(Ctrl+Alt+V)

 css小技巧（2019/5/30）

- id名和class名是区分大小写的 
- 选择器中，只有标签选择器不区分大小写 
- 属性名和属性值是不区分大小写的

2019/6/6

生成随机6为字符串

String verifyCode = String.valueOf(new Random().nextInt(899999) + 100000);

 2019/11/13

完整发布，设置版本号，不需要让用户清理缓存