Springboot項目實戰（一）：構建框架，異常處理

1.今天實現基本的構建框架，異常處理，日誌處理

直接傳送到目錄網址，點我！！！！

-首先我們這裏插入 AOP的基本概念
@Aspect(切面): 通常是一個類，裏面可以定義切入點和通知
JointPoint(連接點): 程序執行過程中明確的點，一般是方法的調用
Advice(通知): AOP在特定的切入點上執行的增強處理:
@Before: 標識一個前置增強方法，相當於BeforeAdvice的功能
@After: final增強，不管是拋出異常或者正常退出都會執行。
@AfterReturning: 後置增強，似於AfterReturningAdvice, 方法正常退出時執行
@AfterThrowing: 異常拋出增強，相當於ThrowsAdvice
@Around: 環繞增強，相當於MethodInterceptor
Pointcut(切入點): 帶有通知的連接點，在程序中主要體現爲書寫切入點表達式
AOP Proxy：AOP框架創建的對象，代理就是目標對象的加強。Spring中的AOP代理可以使JDK動態代理，也可以是CGLIB代理，前者基於接口，後者基於子類。
1.這是初期創建好項目的整體結構

2.
這裏是pom.xml導入的依賴
`<?xml version="1.0" encoding="UTF-8"?>

4.0.0

<groupId>com.xyj</groupId>
<artifactId>blog</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>blog</name>
<description>Demo project for Spring Boot</description>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.7.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
    <thymeleaf.version>3.0.2.RELEASE</thymeleaf.version>
    <thymeleaf-layout-dialect.version>2.1.1</thymeleaf-layout-dialect.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-aop</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-api</artifactId>
        <version>5.5.0</version>
        <scope>test</scope>
    </dependency>


</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

3.application.yml文件配置，application-dev.yml, application-pro.yml三個yml配置，這樣做爲了區別生產環境，輸出日誌

spring:
  thymeleaf:
    mode: HTML
  profiles:
    active: dev

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/blog?useUnicode=true&characterEncoding=utf-8
    username: root
    password: 123456
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true

logging:
  level:
    root: info
    com.lrm: debug
  file: log/blog-dev.log

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/blog?useUnicode=true&characterEncoding=utf-8
    username: root
    password: 123456


  jpa:
    hibernate:
      ddl-auto: none
    show-sql: true

logging:
  level:
    root: warn
    com.lrm: info
  file: log/blog-pro.log
server:
  port: 8081

4.這裏是logback-spring.xml的配置

<?xml version="1.0" encoding="UTF-8" ?>
<configuration>
    <!--包含Spring boot對logback日誌的默認配置-->
    <include resource="org/springframework/boot/logging/logback/defaults.xml" />
    <property name="LOG_FILE" value="${LOG_FILE:-${LOG_PATH:-${LOG_TEMP:-${java.io.tmpdir:-/tmp}}}/spring.log}"/>
    <include resource="org/springframework/boot/logging/logback/console-appender.xml" />

    <!--重寫了Spring Boot框架 org/springframework/boot/logging/logback/file-appender.xml 配置-->
    <appender name="TIME_FILE"
              class="ch.qos.logback.core.rolling.RollingFileAppender">
        <encoder>
            <pattern>${FILE_LOG_PATTERN}</pattern>
        </encoder>
        <file>${LOG_FILE}</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${LOG_FILE}.%d{yyyy-MM-dd}.%i</fileNamePattern>
            <!--保留歷史日誌一個月的時間-->
            <maxHistory>30</maxHistory>
            <!--
            Spring Boot默認情況下，日誌文件10M時，會切分日誌文件,這樣設置日誌文件會在100M時切分日誌
            -->
            <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>10MB</maxFileSize>
            </timeBasedFileNamingAndTriggeringPolicy>

        </rollingPolicy>
    </appender>

    <root level="INFO">
        <appender-ref ref="CONSOLE" />
        <appender-ref ref="TIME_FILE" />
    </root>

</configuration>
        <!--
            1、繼承Spring boot logback設置（可以在appliaction.yml或者application.properties設置logging.*屬性）
            2、重寫了默認配置，設置日誌文件大小在100MB時，按日期切分日誌，切分後目錄：

                blog.2017-08-01.0   80MB
                blog.2017-08-01.1   10MB
                blog.2017-08-02.0   56MB
                blog.2017-08-03.0   53MB
                ......
        -->

5.ControllerExceptionHandler類

package com.xyj.blog.handler;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;

/**
 * @author xyj
 * @date 2020/4/3 -21:19
 * 異常返回error
 */
@ControllerAdvice
public class ControllerExceptionHandler {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());


    @ExceptionHandler(Exception.class)
    public ModelAndView exceptionHander(HttpServletRequest request, Exception e) throws Exception {
        logger.error("Requst URL : {}，Exception : {}", request.getRequestURL(),e);

        if (AnnotationUtils.findAnnotation(e.getClass(), ResponseStatus.class) != null) {
            throw e;
        }

        ModelAndView mv = new ModelAndView();
        mv.addObject("url",request.getRequestURL());
        mv.addObject("exception", e);
        mv.setViewName("error/error");
        return mv;
    }
}

小黑板重點來了

爲了讓你的404,500不那麼難看，所以這裏我們先簡易的做個錯誤跳轉的頁面。
1.NotFoundException類

package com.xyj.blog;

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;


@ResponseStatus(HttpStatus.NOT_FOUND)
public class NotFoundException extends RuntimeException {

    public NotFoundException() {
    }

    public NotFoundException(String message) {
        super(message);
    }

    public NotFoundException(String message, Throwable cause) {
        super(message, cause);
    }
}

2.IndexController，這裏故意做一個錯誤，你可以試驗一下500錯誤9/0

package com.xyj.blog.web;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

/**
 * @author xyj
 * @date 2020/4/3 -21:13
 */
@Controller
public class IndexController {

    @GetMapping("/")
    public String index() {
       int i = 9/0;//這裏故意做一個錯誤，你可以試驗一下500錯誤
//        String blog = null;
//        if (blog == null) {
//            throw  new NotFoundException("博客不存在");
//        }
        return "index";
    }

    @GetMapping("/blog")
    public String blog() {
        return "blog";
    }

}

3.400.500錯誤頁面你可以從網上嫖一個漂亮的模板，我這裏就很簡單了

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>404</title>
</head>
<body>
<h1>404</h1>
</body>
</html>

你可以在localhost：8080/後面隨便瞎輸入一個網址，這樣就可以測試你的跳轉是否成功

查看目錄網址，直接傳送