springboot框架的全局异常处理方案

系统框架搭建的前期过程中，为了约束代码规范，我们会对一些通用功能做一些处理，比如声明一些系统公用错误类、封装通用返回结果、统一异常处理等，这样做的优势是团队开发过程中能够形成统一的代码规范，增强代码可读性，同时又便于后期代码维护。本文主要介绍下框架中异常的处理：

1.声明全局异常处理类，并添加@ControllerAdvice和@RestController注解 代码如下：

@RestController
public class GlobalExceptionHandler {
	
    private final Logger logger = Logger.getLogger(GlobalExceptionHandler.class);

    //空指针异常
    @ExceptionHandler(NullPointerException.class)
    public Map<String, Object> nullPointer(NullPointerException e,HttpServletRequest req){
        logger.error(e.getMessage());
		e.printStackTrace();
        return ResultObject.newResultObj(ErrorCode.NULLPOINTER);
    }
	
    //IO异常
    @ExceptionHandler(IOException.class,HttpServletRequest req, HttpServletResponse res)
    public Map<String, Object> IOException(IOException e){
    	  logger.error(e.getMessage());
		  e.printStackTrace();
          return ResultObject.newResultObj(ErrorCode.IOEXCEPTION);
    }
    
	
    //权限不足异常	
    @ExceptionHandler(UnauthorizedException.class)
    public Map<String, Object> unauth(HttpServletRequest req, HttpServletResponse res){
	return ResultObject.newResultObj(ErrorCode.UNAUTH);
    }
	
    //未登录异常	
    @ExceptionHandler(AuthorizationException.class)
    public Map<String, Object> unlogin(HttpServletRequest req, HttpServletResponse res){
	return ResultObject.newResultObj(ErrorCode.NOTLOGIN);
    }
	
    //其它异常
    @ExceptionHandler(Exception.class)
    public Map<String, Object> error(Exception e,HttpServletRequest req, HttpServletResponse res){
	logger.error(e.getMessage());
	e.printStackTrace();
	return ResultObject.newResultObj(ErrorCode.SYSTEM);
    }
	
}

2.声明系统通用错误处理类

 * 系统通用错误处理类
 */
public class ErrorCode {

    //返回码
    private int code = 0;
	
    //描述信息
    private String errmsg = "SUCCESS";
	
    //成功
    public static final ErrorCode SUCCESS 					    = new ErrorCode(0,"SUCCESS");
    public static final ErrorCode PARAMS 					    = new ErrorCode(100000,"参数错误");
    public static final ErrorCode SYSTEM 					    = new ErrorCode(100001,"系统错误");
    public static final ErrorCode UNLOGIN 					    = new ErrorCode(100002,"未登录");
    public static final ErrorCode UNAUTH 					    = new ErrorCode(100003,"权限错误");
    public static final ErrorCode NULLPOINTER 					= new ErrorCode(100004,"空指针错误");
    public static final ErrorCode IOEXCEPTION 					= new ErrorCode(100005,"IO错误");
    public static final ErrorCode UPLOAD_FAIL 					= new ErrorCode(100006,"文件上传失败");
    public static final ErrorCode REPEAT 					    = new ErrorCode(100007,"数据已存在");

    public ErrorCode() {}

    @Override
    public String toString() {
        return String.format("{\"errmsg\": \"%s\", \"code\": %d}", errmsg, code);
    }

    public int getCode() {
        return code;
    }

    public ErrorCode setCode(int code) {
        this.code = code;
        return this;
    }

    public String getErrmsg() {
        return errmsg;
    }

    public ErrorCode setErrmsg(String errmsg) {
        this.errmsg = errmsg;
        return this;
    }

    public ErrorCode(int code, String errmsg) {
        this.code = code;
        this.errmsg = errmsg;
    }

}

3.声明全局异常处理类中的结果返回类

import java.util.Map;
import javax.servlet.http.HttpServletResponse;
import com.xxx.ErrorCode;//此处引用自己errorCode类所在的包路径
import org.json.JSONObject;

public class ResultObject {	
	
	/**
	 * 输出错误信息
	 * @param errorCode
	 */
	public static Map<String, Object> newResultObj(ErrorCode errorCode){
		Map<String, Object> obj = new HashMap<String, Object>();
		obj.put("code", errorCode.getCode());
		obj.put("errmsg", errorCode.getErrmsg());
		return obj;
	}
	
	/**
	 * 输出带数据的成功信息
	 * @param data
	 */
	public static Map<String, Object> newResultObj(Object data){
		Map<String, Object> obj = new HashMap<String, Object>();
		obj.put("code", ErrorCode.SUCCESS.getCode());
		obj.put("errmsg", ErrorCode.SUCCESS.getErrmsg());
		if(null != data){
			obj.put("data", data);
		}
		return obj;		
	}
	
	/**
	 * 输出带数据的错误信息
	 * @param errorCode
	 * @param data
	 */
	public static Map<String, Object> newResultObj(ErrorCode errorCode, Object data){
		Map<String, Object> obj = new HashMap<String, Object>();
		obj.put("code", errorCode.getCode());
		obj.put("errmsg", errorCode.getErrmsg());
		if(null != data){
			obj.put("data", data);
		}
		return obj;				
	}
	
	
	/**
	 * 输出结果
	 */
	public static void outputResult(HttpServletResponse response, ErrorCode errorCode){
		try {
			JSONObject json = new JSONObject();
			json.put("code", errorCode.getCode());
			json.put("errmsg", errorCode.getErrmsg());
			
			response.setCharacterEncoding("UTF-8");
			response.setContentType("application/json;charset=UTF-8");
			response.getWriter().write(json.toString());
		} catch (Exception e1) {
		}
	}
}