创建spring项目步骤一

前言

该文档主要介绍如何创建一个简单的、能够正常运行的spring项目。为往后项目的开发提供便利

创建spring项目

创建maven项目

使用sts开发软件创建项目,STS是Spring Tool Suite的简称，该软件是一个基于Eclipse环境的，用于开发spring应用程序的软件。其提供了很多spring相关的辅助工具，为开发项目提供诸多便利。

导入spring-mvc jar包

编辑spring项目的pom.xml文件，加入spring-mvc容器 相关jar依赖、spring-ioc容器相关的jar

    4.0.0
    com.bear.simple_spring
    simple_spring
    0.0.1-SNAPSHOT

    
        
        
            org.springframework
            spring-webmvc
            5.1.2.RELEASE
        
        
            org.springframework
            spring-web
            5.1.2.RELEASE
        
        
        
            com.fasterxml.jackson.core
            jackson-databind
            2.9.8
        
        
            com.fasterxml
            classmate
            1.4.0
        
    

配置servlet容器web.xml

• 编辑web.xml文件，让servlet容器启动的时候加载spring-mvc配置文件及spring-ioc的配置文件，以启动spring-mvc容器与spring-ioc容器

    
    
        springDispatcherServlet
        org.springframework.web.servlet.DispatcherServlet
        
            contextConfigLocation
            
            classpath:spring-mvc.xml
        
        1
    
    
    
        springDispatcherServlet
        
        /
    

    
    
        contextConfigLocation
        classpath:spring-beans.xml
    
    
        org.springframework.web.context.ContextLoaderListener
    

创建spring-mvc容器的配置文件【spring-mvc.xml】

创建spring-mvc的配置文件

创建spring-ioc容器的配置文件【spring-beans.xml】

测试spring-mvc项目是否创建成功

• 编写controller

  package com.bear.simple.spring.controller;
  
  import javax.servlet.http.HttpServletRequest;
  
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.web.bind.annotation.RequestMapping;
  import org.springframework.web.bind.annotation.RequestParam;
  import org.springframework.web.bind.annotation.RestController;
  
  import com.bear.simple.spring.entity.Account;
  import com.bear.simple.spring.service.AccountService;
  
  @RestController
  @RequestMapping("account")
  public class AccountController {
  
  @Autowired
  private AccountService accountService;
  
  /**
   * 获取帐号信息
   * @param id
   * @param request
   * @return
   */
  @RequestMapping("/get")
  public Account getAccount(@RequestParam String id,HttpServletRequest request) {
      if(null == id || "".equals(id)) 
          throw new RuntimeException("请求参数缺少id");
      Account result = accountService.loadAccountById(id);
      return result;
  }
  }

• 编写实体层

  package com.bear.simple.spring.entity;
  
  /**
  * 登陆帐号信息
  * @author bear
  *
  *
  public class Account {
  //登陆帐号ID
  private String id;
  //登陆帐号
  private String acccountNo;
  //帐号密码
  private String password;
  //帐号描述
  private String desc;
  //帐号是否启用 0 禁用 1启用，默认为启用
  private int enable = 1;
  
  public Account(String id, String acccountNo, String password) {
      super();
      this.id = id;
      this.acccountNo = acccountNo;
      this.password = password;
  }
  
  public Account(String id, String acccountNo, String password, String desc, int enable) {
      super();
      this.id = id;
      this.acccountNo = acccountNo;
      this.password = password;
      this.desc = desc;
      this.enable = enable;
  }
  
  public Account() {
      super();
  }
  
  public String getId() {
      return id;
  }
  
  public void setId(String id) {
      this.id = id;
  }
  
  public String getAcccountNo() {
      return acccountNo;
  }
  
  public void setAcccountNo(String acccountNo) {
      this.acccountNo = acccountNo;
  }
  
  public String getPassword() {
      return password;
  }
  
  public void setPassword(String password) {
      this.password = password;
  }
  
  public int getEnable() {
      return enable;
  }
  
  public void setEnable(int enable) {
      this.enable = enable;
  }
  
  public Boolean isEnable() {
      return 1 == this.enable;
  }
  
  @Override
  public int hashCode() {
      final int prime = 31;
      int result = 1;
      result = prime * result + ((acccountNo == null) ? 0 : acccountNo.hashCode());
      result = prime * result + ((desc == null) ? 0 : desc.hashCode());
      result = prime * result + enable;
      result = prime * result + ((id == null) ? 0 : id.hashCode());
      result = prime * result + ((password == null) ? 0 : password.hashCode());
      return result;
  }
  
  @Override
  public boolean equals(Object obj) {
      if (this == obj)
          return true;
      if (obj == null)
          return false;
      if (getClass() != obj.getClass())
          return false;
      Account other = (Account) obj;
      if (acccountNo == null) {
          if (other.acccountNo != null)
              return false;
      } else if (!acccountNo.equals(other.acccountNo))
          return false;
      if (desc == null) {
          if (other.desc != null)
              return false;
      } else if (!desc.equals(other.desc))
          return false;
      if (enable != other.enable)
          return false;
      if (id == null) {
          if (other.id != null)
              return false;
      } else if (!id.equals(other.id))
          return false;
      if (password == null) {
          if (other.password != null)
              return false;
      } else if (!password.equals(other.password))
          return false;
      return true;
  }
  
  @Override
  public String toString() {
      return "Account [id=" + id + ", acccountNo=" + acccountNo + ", password=" + password + ", desc=" + desc
              + ", enable=" + enable + "]";
  }
  
  }

• 编写服务层

  package com.bear.simple.spring.service;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Optional;
  
  import org.springframework.stereotype.Service;
  
  import com.bear.simple.spring.entity.Account;
  
  @Service
  public class AccountService {
  
  private static final Map cache = new HashMap();
  
  static {
      cache.put("1", new Account("1", "黄大仙", "123456"));
      cache.put("2", new Account("2", "刘不三", "12345678"));
      cache.put("3", new Account("3", "刘不四", "8888888"));
  }
  
  /**
   * 加载帐号，不存在报异常
   * 
   * @param id
   * @return
   */
  public Account loadAccountById(String id) {
      Optional accountOpt = findAccountById(id);
      if (!accountOpt.isPresent())
          throw new RuntimeException(String.format("帐号【%s】不存在", id));
      return accountOpt.get();
  }
  
  /**
   * 查找帐号
   * 
   * @param id
   * @return
   */
  public Optional findAccountById(String id) {
      if (null == id || "".equals(id))
          return Optional.empty();
      Account account = cache.get(id);
      return Optional.ofNullable(account);
  }
  
  }

• 测试请求处理

  使用postman软件测试

  

统一返回结果

• 编写返回结果实体类【该类包含成功返回，异常返回与错误返回】

  package com.bear.simple.spring.entity;
  
  import java.io.PrintWriter;
  import java.io.StringWriter;
  
  public class JsonData {
  //是否正确返回
  private final boolean ret;
  //状态码
  private String code = "000";
  //数据
  private Object data;
  //提示信息
  private String msg;
  //异常详细信息
  private String detail;
  
  private JsonData(boolean ret) {
      this.ret = ret;
  }   
  /**
   * 创建错误返回结果
   * @param msg 提示信息
   * @return
   */
  public static JsonData error(String msg) {
      JsonData result = new JsonData(false);
      result.msg = msg;
      result.code = "999";
      return result;
  }
  
  public static JsonData error(String msg,Exception e,String code) {
      JsonData result = new JsonData(false);
      result.msg = msg;
      result.code = code;
      result.detail = getStackTraceInfo(e);
      return result;
  }
  
  public static JsonData error(Exception e) {
      JsonData result = new JsonData(false);
      result.msg = e.getMessage();
      result.code = "999";
      result.detail = getStackTraceInfo(e);
      return result;
  }
  
  public static JsonData error(Exception e,String code) {
      JsonData result = new JsonData(false);
      result.msg = e.getMessage();
      result.code = code;
      result.detail = getStackTraceInfo(e);
      return result;
  }
  
  public static JsonData success(Object data,String msg) {
      JsonData result = new JsonData(true);
      result.msg = msg;
      result.data = data;
      return result;
  }
  public static JsonData success(Object data) {
      return success(data, null);
  }
  
  public static JsonData success() {
      return success(null,null);
  }
  
  public String getCode() {
      return code;
  }
  
  public Object getData() {
      return data;
  }
  
  public String getMsg() {
      return msg;
  }
  
  public String getDetail() {
      return detail;
  }
  
  public boolean isRet() {
      return ret;
  }
  
  /**
   * 打印异常堆栈信息
   * @param e
   * @return
   */
  public static String getStackTraceInfo(Exception e) {
        StringWriter sw = new StringWriter();
        PrintWriter pw = new PrintWriter(sw);
        try {
            e.printStackTrace(pw);
            pw.flush();
            sw.flush();
            return sw.toString();
        } finally {
            try {
                pw.close();
            } catch (Exception ex) {
                ex.printStackTrace();
            }
            try {
                sw.close();
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
    }
  
  }

统一异常处理

编写异常处理控制器（统一处理系统发生的所有异常）

package com.bear.simple.spring.controller;

import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;

import com.bear.simple.spring.entity.JsonData;

@ControllerAdvice
public class ExceptionController {

    /**
     * 处理特定异常
     * @param ex
     * @return
     */
    @ExceptionHandler
    @ResponseBody
    public JsonData handleUserNotExistException(UserNotExistException ex) {
        if(null == ex.getMessage() || "".equals(ex.getMessage()))
            return JsonData.error("用户不存在", ex, "998");
        return JsonData.error(ex, "998");
    }

    /**
     * 处理上述遗漏的异常
     * @param ex
     * @return
     */
    @ExceptionHandler
    @ResponseBody
    public JsonData handleUserNotExistException(Exception ex) {
        if(null == ex.getMessage() || "".equals(ex.getMessage()))
            return JsonData.error("系统发生未知异常", ex, "999");
        return JsonData.error(ex, "999");
    }
}

添加日志处理

• 日志记录是项目中不可或缺的一部分。它的存在让我们定位问题更为方便。目前使用比较普遍的日志框架有log4j、logback等。当前项目将采用logback。
• 引用logback相应jar包

            org.slf4j
            slf4j-api
            1.7.21
        
        
            ch.qos.logback
            logback-core
            1.1.7
        
        
            ch.qos.logback
            logback-classic
            1.1.7
        

• 编写日志配置文件【logback.xml(名称可自定义)】

  
  
  
  
  
  
  
  
  ${appName}
  
  
  
      
      
          %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
          
      
  
  
  
  
      ${logFilePath}/testFile.log
      true
      
          %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
          
      
  
  
  
  
      
      
          ${logFilePath}/%d{yyyy-MM-dd}.log
          30
      
      
      
          %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
          
      
  
  
  
          
          
              INFO
              ACCEPT
              DENY
          
          
          
              ${logFilePath}/timeout/%d{yyyy-MM-dd}.log
              30
          
          
          
              %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
              
          
      
  
  
  
      
      
  
  
  
  
      
      
  
  

• 使用springmvc启动加载日志配置文件，编辑web.xml文件使用配置监听器加载日志配置文件，只需在web.xml文件中添加如下代码段即可

  
      logbackConfigLocation
      
      C:/developer/apache-tomcat-8.0.32/web_log/logback.xml
  
  
      ch.qos.logback.ext.spring.web.LogbackConfigListener
  

配置统一编码过滤器

• 配置springmvc接收的所有请求的编码格式为utf-8,只需在web.xml文件中添加字符集过滤器即可，添加的内容如下

  
  
      characterEncodingFilter
      org.springframework.web.filter.CharacterEncodingFilter
      
      
          encoding
          UTF-8
      
      
      
          forceEncoding
          true
      
  
  
      characterEncodingFilter
      /*
  

​