公司的很多项目都陆陆续续引入了Spring Boot，通过对Spring Boot的接触了解发现其真的是大大地简化了开发、简化了依赖配置，很多功能注解一下就可以实现，真的是太方便了。下面记录了一个Spring Boot的入门程序实现，包括过滤器、servlet、定时器、全局异常处理、日志、Druid数据源的SQL监控配置。

1，pom.xml文件：

     
        
      
       4.0.0
        
      
       com.zws
        
      
       spring-boot
        
      
       0.0.1-SNAPSHOT
        
      
       jar
        
      
       spring-boot
        
      
       http://maven.apache.org
        
      
           
       
        UTF-8
         
          
      
           
       
        org.springframework.boot
           
       
        spring-boot-starter-parent
           
       
        1.5.10.RELEASE
         
        
      	
       
        	    
        
         org.springframework.boot
        	    
        
         spring-boot-starter-web
        	    
        
         	        
         
          	           
          
           org.springframework.boot
          	           
          
           spring-boot-starter-logging
          	        
         		
        	
       		
       
        	    
        
         org.springframework.boot
        	    
        
         spring-boot-starter-aop
        	
       		
       
        	    
        
         org.springframework.boot
        	    
        
         spring-boot-starter-jdbc
        	
       		
       
        	    
        
         org.mybatis.spring.boot
        	    
        
         mybatis-spring-boot-starter
        	    
        
         1.3.1
        	
       		
       
        	    
        
         com.alibaba
        	    
        
         druid-spring-boot-starter
        	    
        
         1.1.0
        	
       		
       
          	    
        
         mysql
          	    
        
         mysql-connector-java
          	
       		
       
        	    
        
         commons-logging
        	    
        
         commons-logging
        	    
        
         1.2
        	
       		
       
        	    
        
         org.slf4j
        	    
        
         slf4j-api
        	
       		
       
        	    
        
         log4j
        	    
        
         log4j
        	    
        
         1.2.17
        	
       		
       
        	    
        
         com.alibaba
        	    
        
         fastjson
        	    
        
         1.2.46
        	
       		
       
        	    
        
         junit
        	    
        
         junit
        	    
        
         test
        	
         
          
      
             
       
              	  
        
         		      
         
          org.apache.maven.plugins
         			  
         
          maven-compiler-plugin
         			  
         
          			      
          1.8			      
          
           1.8
          			  
         		  
                  
        
                       
         
          org.springframework.boot
                       
         
          spring-boot-maven-plugin
                   
              
         
      
     

可以看到这个文件内容并不多，但是却引入了很多需要的依赖。这里引入的Spring Boot版本为1.5.10.RELEASE，其中spring-boot-maven-plugin插件是Spring Boot提供的打包用的插件。mybatis-spring-boot-starter为MyBatis集成Spring Boot的依赖。druid-spring-boot-starter为阿里开源数据源Druid集成Spring Boot的依赖，它会下载对应的druid jar包，注意这里并没有直接引入Druid依赖，如果直接引入Druid依赖jar包，则druid的监控页面无法显示sql。

2，Spring Boot配置文件resources/application.properties：

server.port=8080server.context-path=/appspring.mvc.throw-exception-if-no-handler-found=truespring.resources.add-mappings=false#tomcat访问日志server.tomcat.basedir=logsserver.tomcat.accesslog.enabled=trueserver.tomcat.accesslog.directory=accessserver.tomcat.accesslog.pattern=%t %a "%r" %s %b (%D ms)datasource.druid.url=jdbc:mysql://localhost/db_boot?useUnicode=true&characterEncoding=utf8&autoReconnect=true&failOverReadOnly=falsedatasource.druid.username=rootdatasource.druid.password=rootdatasource.druid.driver-class-name=com.mysql.jdbc.Driverdatasource.druid.initialSize=5datasource.druid.minIdle=5datasource.druid.maxActive=20datasource.druid.maxWait=60000datasource.druid.minEvictableIdleTimeMillis=300000datasource.druid.validationQuery=select 'x'datasource.druid.testOnBorrow=falsedatasource.druid.testOnReturn=falsedatasource.druid.testWhileIdle=truedatasource.druid.poolPreparedStatements=falsedatasource.druid.maxPoolPreparedStatementPerConnectionSize=100datasource.druid.filters=stat,wall,log4jmybatis.config-location=classpath:mybatis/mybatis-config.xmlmybatis.mapper-locations=classpath:mybatis/mapper/*.xml

application.properties文件为Spring Boot的总配置文件，Spring Boot默认会加载resources目录下的application.properties文件。Spring Boot默认内嵌Tomcat作为web容器，server.port为端口，server.context-path为上下文路径。datasource开头的为druid数据源的配置。

3，MyBatis的配置文件resources/mybatis/mybatis-config.xml:

此配置文件的路径已经配置在了resources/application.properties文件内。

4，resources/mybatis/UserMapper.xml:

     
     
          
      
               
               
               
               
               
       
               select id, name, pass, create_date from user            
        
             	select id, name, pass, create_date from user where id = #{value}    
        
       
      
     

5，Sping Boot启动类Application.java:

package com.zws.be;import javax.sql.DataSource;import org.mybatis.spring.annotation.MapperScan;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.boot.web.servlet.ServletComponentScan;import org.springframework.context.annotation.Bean;import org.springframework.scheduling.annotation.EnableScheduling;import com.alibaba.druid.pool.DruidDataSource;@SpringBootApplication@MapperScan(basePackages = {"com.zws.be.*.mapper"})@ServletComponentScan@EnableSchedulingpublic class Application {		public static void main(String[] args) {		SpringApplication.run(Application.class, args);	}		@Bean("dataSource")	@ConfigurationProperties("datasource.druid")	public DataSource getDruidDataSource() {		return DataSourceBuilder.create().type(DruidDataSource.class).build();	}}

这个是程序启动的入口，里面有mian函数，运行此类即可启动Spring Boot。注解@MapperScan(basePackages = {"com.zws.be.*.mapper"})指定了映射mapper文件的接口所在的包。@EnableScheduling注解用于开启Spring的定时组件，下面会有例子。@ServletComponentScan注解搭配@WebServlet和@WebFilter注解使得定义servlet和filter时非常方便。

6，下面是定义一个简单的restful接口所需的各类：

com.zws.be.user.bean.User：

package com.zws.be.user.bean;import java.util.Date;import org.apache.ibatis.type.Alias;@Alias("User")public class User {	private Long id;	private String name;	private String pass;	private Date createDate;		public Long getId() {		return id;	}	public void setId(Long id) {		this.id = id;	}	public String getName() {		return name;	}	public void setName(String name) {		this.name = name;	}	public String getPass() {		return pass;	}	public void setPass(String pass) {		this.pass = pass;	}	public Date getCreateDate() {		return createDate;	}	public void setCreateDate(Date createDate) {		this.createDate = createDate;	}	@Override	public String toString() {		return "User [id=" + id + ", name=" + name + ", pass=" + pass + ", createDate=" + createDate + "]";	}	}

com.zws.be.user.mapper.UserMapper：

package com.zws.be.user.mapper;import java.util.List;import com.zws.be.user.bean.User;public interface UserMapper {	List
     
       getAll();		User getUserById(Long id);}
     

com.zws.be.user.service.UserService：

package com.zws.be.user.service;import java.util.List;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import com.zws.be.user.bean.User;import com.zws.be.user.mapper.UserMapper;@Servicepublic class UserService {	@Autowired	private UserMapper userMapper;		public List
     
       getUsers() {		return userMapper.getAll();	}		public User getUser(Long id) {		return userMapper.getUserById(id);	}}
     

com.zws.be.user.controller.UserController：

package com.zws.be.user.controller;import org.apache.log4j.Logger;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RestController;import com.alibaba.fastjson.JSON;import com.alibaba.fastjson.serializer.SerializerFeature;import com.zws.be.user.bean.User;import com.zws.be.user.service.UserService;@RestController@RequestMapping("/user")public class UserController {	public Logger logger = Logger.getLogger(UserController.class);		@Autowired	private UserService userService;	@RequestMapping(value="/{id}", method=RequestMethod.GET, produces = "application/json")	public String hello(@PathVariable Long id) {		User user = userService.getUser(id);		return JSON.toJSONString(user, SerializerFeature.WriteDateUseDateFormat);	}}

7，配置Druid的sql监控servlet：

package com.zws.be.filter;import javax.servlet.annotation.WebServlet;import com.alibaba.druid.support.http.StatViewServlet;/** * DRUID的sql监控 * @author wensh.zhu * @2018-03-11 */@WebServlet(name="monitorSrvlet", urlPatterns= {"/druid/*"})public class MonitorServlet extends StatViewServlet {		private static final long serialVersionUID = -2211104135110049275L;}

启动后访问

8，过滤器例子：

package com.zws.be.filter;import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.annotation.WebFilter;import org.apache.log4j.Logger;@WebFilter(filterName="filterDemo", urlPatterns = {"/*"})public class FilterDemo implements Filter{	private Logger logger = Logger.getLogger(FilterDemo.class);	@Override	public void destroy() {}	@Override	public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain chain)			throws IOException, ServletException {		logger.info("FilterDemo is working...");		chain.doFilter(arg0, arg1);	}	@Override	public void init(FilterConfig arg0) throws ServletException {					}}

9，定时器例子：

package com.zws.be.timer;import org.apache.log4j.Logger;import org.springframework.scheduling.annotation.Scheduled;import org.springframework.stereotype.Component;@Componentpublic class TimerDemo {	private Logger logger = Logger.getLogger(getClass());	@Scheduled(cron = "0/30 * * * * *")  	public void timer() {		logger.info("定时器例子");	}}

10，全局异常处理：

package com.zws.be.exception;import org.apache.log4j.Logger;import org.springframework.web.bind.annotation.ExceptionHandler;import org.springframework.web.bind.annotation.ResponseBody;import org.springframework.web.bind.annotation.RestControllerAdvice;/** * 全局异常处理 * @author wensh.zhu * @2018-03-11 */@RestControllerAdvicepublic class ExceptionAdvice {	private Logger logger = Logger.getLogger(getClass());	private String pattern = "抱歉，异常了：{0}";	@ExceptionHandler(value = {Exception.class})	@ResponseBody	public String handleAllException(Exception e, HttpServletRequest req, HttpServletResponse resp) {		logger.error("接口调用异常", e);		if (e instanceof NoHandlerFoundException) {			String reqURI = req.getRequestURI().toString();			return MessageFormat.format(pattern, "资源" + reqURI + "不存在！！！");		}		return MessageFormat.format(pattern, e.getMessage());	}}

11，log4j配置文件resources/log4j.properties：

log4j.rootLogger=INFO, stdout, infoLog, errorLoglog4j.appender.stdout = org.apache.log4j.ConsoleAppenderlog4j.appender.stdout.layout = org.apache.log4j.PatternLayoutlog4j.appender.stdout.layout.conversionPattern = %d{yyyy-MM-dd HH\:mm\:ss}|%p|%C|%M|%L|%m%nlog4j.appender.infoLog=com.zws.be.log.MyRollingFileAppenderlog4j.appender.infoLog.File=logs/info/info.loglog4j.appender.infoLog.Threshold = infolog4j.appender.infoLog.layout=org.apache.log4j.PatternLayoutlog4j.appender.infoLog.layout.ConversionPattern=%d{yyyy-MM-dd HH\:mm\:ss}|%p|%C|%M|%L|%m%nlog4j.appender.errorLog=com.zws.be.log.MyRollingFileAppenderlog4j.appender.errorLog.File=logs/error/error.loglog4j.appender.errorLog.Threshold = errorlog4j.appender.errorLog.layout=org.apache.log4j.PatternLayoutlog4j.appender.errorLog.layout.ConversionPattern=%d{yyyy-MM-dd HH\:mm\:ss}|%p|%C|%M|%L|%m%n

自定义日志生成文件名称：

package com.zws.be.log;import java.io.File;import java.io.IOException;import java.io.InterruptedIOException;import org.apache.log4j.Priority;import org.apache.log4j.RollingFileAppender;import org.apache.log4j.helpers.CountingQuietWriter;import org.apache.log4j.spi.LoggingEvent;public class MyRollingFileAppender extends RollingFileAppender{	private long nextRollover = 0L;		public void rollOver() {		File target, file;				if (qw != null) {			long size = ((CountingQuietWriter) qw).getCount();			nextRollover = size + maxFileSize;		}				boolean renameSuccessed = true;		if (maxBackupIndex > 0) {			file = new File(getRollingFileName(fileName, maxBackupIndex));			if (file.exists()) {				renameSuccessed = file.delete();			}						for (int i = maxBackupIndex - 1; i >= 1 && renameSuccessed; i --) {				file = new File(getRollingFileName(fileName, i));				if (file.exists()) {					target = new File(getRollingFileName(fileName, i + 1));					renameSuccessed = file.renameTo(target);				}			}						if (renameSuccessed) {				target = new File(getRollingFileName(fileName, 1));				closeFile();				renameSuccessed = file.renameTo(target);								if (!renameSuccessed) {					try {						setFile(fileName, true, bufferedIO, bufferSize);					} catch (IOException e) {						if (e instanceof InterruptedIOException) {							Thread.currentThread().interrupt();						}					}				}			}		}	}		private String getRollingFileName(String fileName, int index) {		String fName = "";		String newIndex = index < 10 ? ("0" + index) : String.valueOf(index);		if (index > 0) {			fName = fileName.replace(".log", "") + "_" + newIndex + ".log";		} else {			fName = fileName;		}		return fName;	}		@Override	protected void subAppend(LoggingEvent event) {		super.subAppend(event);		if (fileName != null && qw != null) {			long size = ((CountingQuietWriter) qw).getCount();			if (size >= maxFileSize && size >= nextRollover) {				rollOver();			}		}	}		@Override	public boolean isAsSevereAsThreshold(Priority priority) {		String level = priority.toString();		if ("ERROR".equals(level)) {			return getThreshold().equals(priority);		}				return super.isAsSevereAsThreshold(priority);	}}

12，Spring MVC请求参数以及返回信息自动日志的辅助类：

package com.zws.be.log;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.text.MessageFormat;import org.apache.log4j.Logger;import org.springframework.core.MethodParameter;import org.springframework.http.MediaType;import org.springframework.http.converter.HttpMessageConverter;import org.springframework.http.server.ServerHttpRequest;import org.springframework.http.server.ServerHttpResponse;import org.springframework.web.bind.annotation.ControllerAdvice;import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;/** * 用于请求参数、响应信息的自动日志。 * @author wensh.zhu * @2018-03-11 */@ControllerAdvice(basePackages = {"com.zws.be"})public class LogResponseBodyAdvice implements ResponseBodyAdvice
     
      {		private String pattern = "\n---BEGIN---\nReqURI:{0}\nParams:{1}\nMethod:{2}\nReturn:{3}\n---END---";		private Logger logger = Logger.getLogger(LogResponseBodyAdvice.class);	@Override	public String beforeBodyWrite(String rtnMsg, MethodParameter param, MediaType arg2,			Class
      > arg3, ServerHttpRequest req, ServerHttpResponse resp) {		String clazName = param.getDeclaringClass().getName();		String mtdName = param.getMethod().getName();		String reqURI = req.getURI().toString();		String reqParams = getReqParams(req);		String log = getLog(reqURI, reqParams, clazName + "." + mtdName, rtnMsg);		logger.info(log);		return rtnMsg;	}	@Override	public boolean supports(MethodParameter arg0, Class
      > arg1) {		return true;	}		private String getLog(String reqURI, String reqParams, String proMethod, String rtnMsg) {		return MessageFormat.format(pattern, reqURI, reqParams, proMethod, rtnMsg);	}	private String getReqParams(ServerHttpRequest req) {		StringBuilder body = new StringBuilder();		String line = null;		BufferedReader reader = null;		try {			reader = new BufferedReader(new InputStreamReader(req.getBody(), "UTF-8"));			while ((line = reader.readLine()) != null) {				body.append(line);			}		} catch (IOException e) {			logger.error("I/O error ", e);		} finally {			try {				if (reader != null) {					reader.close();				}			} catch (IOException e) {				logger.error("I/O error ", e);			}		}				return body.toString();	}}
     

此类功能为将Spring MVC接受到请求的参数、处理请求对应的方法、请求返回内容自动打印到日志文件内，在接口出现问题的时候方便排查，日志输出样例：

---BEGIN---ReqURI:http://localhost:8080/app/user/1Params:Method:com.zws.be.user.controller.UserController.helloReturn:{"createDate":"2018-03-04 15:44:25","id":1,"name":"zhangsan","pass":"zhangsan@123"}---END---

13，运行Application，访问

查看druid的监控：

项目目录结构图：