场景

1.throws是在方法上抛出异常，throw是在语句上抛出异常。

2.try-catch是在catch里处理try捕获异常并处理。

3.一般try-catch是在上层Controller中使用，而在Service以及dao层的接口上用throws向上级抛出异常。

避免踩坑：

在Controller中添加了try-catch，没有在sevice以及dao层添加throws，导致在dao层调用mapper文件中

某方法时在if标签中有错误时：

<if test="wmsReceiveOrder != null and wmsReceiveOrder.purchaseCode!=null and wmsReceiveOrder.purchaseCode!=''" >and ro.purchase_code=#{wmsReceiveOrder.purchaseCode} </if>

不会输出异常信息。

实现

1.在Controller层添加try-catch

   try {IPage<WmsReceiveOrderVO> page = receiveOrderService.pageTray(pageEntity, vo);Log.getInst(this).debug("doPageForRoleTable test:" + vo.getColumns().get(0).getSearch());return dataTablesResultJsonVO;} catch (Exception ex) {Log.getInst().debug("获取收货单数据接口:",ex);Log.getInst(this).debug("doPageForRoleTable test:" + vo.getColumns().get(0).getSearch());return dataTablesResultJsonVO;}

2.调用service层时，需要在service的接口上添加throws

public interface IWmsReceiveOrderService extends IService<WmsReceiveOrder> {IPage<WmsReceiveOrderVO> pageTray(Page<WmsReceiveOrderVO> page, DataTablesJsonVO vo)  throws Exception; }

3.同样在dao层接口上也要添加throws

public interface IWmsReceiveOrderService extends IService<WmsReceiveOrder> {IPage<WmsReceiveOrderVO> pageTray(Page<WmsReceiveOrderVO> page, DataTablesJsonVO vo)  throws Exception; }

4.其中Controller中分Log是在slf4j基础上封装的打印日志的工具类。

package com.ws.kernel.log;import org.slf4j.Logger; import org.slf4j.LoggerFactory;import java.util.HashMap; import java.util.Map;public class Log {private static String logPrefix = " log -> ";private static Log instance;private static Logger logger = null;private static Map<Class, Logger> loggerList = new HashMap<Class, Logger>(); //用于缓存logger对象/*** 定义私有构造方法实现单例*/private Log() {}/*** 功能说明：获取服务实例的静态方法* 修改说明：* @author badao* @date* @param obj 传入调用此方法的对象* @return*/public synchronized static Log getInst(Object obj) {if (instance == null) {instance = new Log();}Log.logger = loggerList.get(obj.getClass());if (Log.logger == null) {Log.logger = LoggerFactory.getLogger(obj.getClass());//Log.logger = Logger.getLogger(obj.getClass());loggerList.put(obj.getClass(), Log.logger);}return instance;}/*** 功能说明：获取服务实例的静态方法* 修改说明：* @author baadao* @date* @param clazz 传入调用此方法的类型* @return*/public synchronized static Log getInst(Class clazz) {if (instance == null) {instance = new Log();}Log.logger = loggerList.get(clazz);if (Log.logger == null) {Log.logger = LoggerFactory.getLogger(clazz);loggerList.put(clazz, Log.logger);}return instance;}/*** 功能说明：获取服务实例的静态方法* 修改说明：* @author badao* @date* @return*/public synchronized static Log getInst() {if (instance == null) {instance = new Log();}Log.logger = loggerList.get(Log.class);if (Log.logger == null) {Log.logger = LoggerFactory.getLogger(Log.class);loggerList.put(Log.class, Log.logger);}return instance;}public void trace(String message) {Log.logger.trace(logPrefix + message);}public void trace(String message, Throwable t) {Log.logger.trace(logPrefix + message, t);}public void debug(String message) {Log.logger.debug(logPrefix + message);}public void debug(String message, Throwable t) {Log.logger.debug(logPrefix + message, t);}public void info(String message) {Log.logger.info(logPrefix + message);}public void info(String message, Throwable t) {Log.logger.info(logPrefix + message, t);}public void warn(String message) {Log.logger.warn(logPrefix + message);}public void warn(String message, Throwable t) {Log.logger.warn(logPrefix + message, t);}public void error(String message,Object... arguments) {Log.logger.error(logPrefix + message,arguments);}public void error(String message, Throwable t, Object... arguments) {Log.logger.error(logPrefix + message,t,arguments);} }

 

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