之前，调用第3方服务，每个方法都差不多“长”这样, 写起来啰嗦, 改起来麻烦, 还容易改漏。
public void authorizeRoleToUser(Long userId, List<Long> roleIds) {
try {
power.authorizeRoleToUser(userId, roleIds);
} catch (MotanCustomException ex) {
if (ex.getCode().equals(MSUserException.notLogin().getCode()))
throw UserException.notLogin();
if (ex.getCode().equals(MSPowerException.haveNoPower().getCode()))
throw PowerException.haveNoPower();
throw ex;
} catch (MotanServiceException ex) {
CatHelper.logEventService("Power-authorizeRoleToUser", "authorizeRoleToUser", ex.getStatus(),
ex.getErrorCode(), ex.getMessage());
throw ex;
} catch (MotanAbstractException ex) {
CatHelper.logEventService("Power-authorizeRoleToUser", "authorizeRoleToUser", ex.getStatus(),
ex.getErrorCode(), ex.getMessage());
throw ex;
} catch (Exception ex) {
CatHelper.logError(ex);
throw ex;
}
}
我经过学习和提取封装, 将try ... catch ... catch .. 提取为公用, 得到这2个方法:
import java.util.function.Supplier; public static <T> T tryCatch(Supplier<T> supplier, String serviceName, String methodName) {
try {
return supplier.get();
} catch (MotanCustomException ex) {
if (ex.getCode().equals(MSUserException.notLogin().getCode()))
throw UserException.notLogin();
if (ex.getCode().equals(MSPowerException.haveNoPower().getCode()))
throw PowerException.haveNoPower();
throw ex;
} catch (MotanServiceException ex) {
CatHelper.logEventService(serviceName + "-" + methodName, methodName, ex.getStatus(), ex.getErrorCode(),
ex.getMessage());
throw ex;
} catch (MotanAbstractException ex) {
CatHelper.logEventService(serviceName + "-" + methodName, methodName, ex.getStatus(), ex.getErrorCode(),
ex.getMessage());
throw ex;
} catch (Exception ex) {
CatHelper.logError(ex);
throw ex;
}
} public static void tryCatch(Runnable runnable, String serviceName, String methodName) {
tryCatch(() -> {
runnable.run();
return null;
}, serviceName, methodName);
}
现在用起来是如此简洁。像这种无返回值的:
public void authorizeRoleToUser(Long userId, List<Long> roleIds) {
tryCatch(() -> { power.authorizeRoleToUser(userId, roleIds); }, "Power", "authorizeRoleToUser");
}
还有这种有返回值的:
public List<RoleDTO> listRoleByUser(Long userId) {
return tryCatch(() -> power.listRoleByUser(userId), "Power", "listRoleByUser");
}
这是我的第一篇Java文章。学习Java的过程中，既有惊喜，也有失望。以后会继续来分享心得。
--------------我是分隔线---------------
后来发现以上2个方法还不够用, 原因是有一些方法会抛出 checked 异常, 于是又再添加了一个能处理异常的, 这次意外发现Java的throws也支持泛型, 赞一个:
public static <T, E extends Throwable> T tryCatchException(SupplierException<T, E> supplier, String serviceName,
String methodName) throws E {
try {
return supplier.get();
} catch (MotanCustomException ex) {
if (ex.getCode().equals(MSUserException.notLogin().getCode()))
throw UserException.notLogin();
if (ex.getCode().equals(MSPowerException.haveNoPower().getCode()))
throw PowerException.haveNoPower();
throw ex;
} catch (MotanServiceException ex) {
CatHelper.logEventService(serviceName + "-" + methodName, methodName, ex.getStatus(), ex.getErrorCode(),
ex.getMessage());
throw ex;
} catch (MotanAbstractException ex) {
CatHelper.logEventService(serviceName + "-" + methodName, methodName, ex.getStatus(), ex.getErrorCode(),
ex.getMessage());
throw ex;
} catch (Exception ex) {
CatHelper.logError(ex);
throw ex;
}
} @FunctionalInterface
public interface SupplierException<T, E extends Throwable> { /**
* Gets a result.
*
* @return a result
*/
T get() throws E;
}
为了不至于维护两份catch集, 将原来的带返回值的tryCatch改为调用tryCatchException:
public static <T> T tryCatch(Supplier<T> supplier, String serviceName, String methodName) {
return tryCatchException(() -> supplier.get(), serviceName, methodName);
}
这个世界又完善了一步。
---------------我是第2条分隔线--------------------
前面制作了3种情况:
1.无返回值,无 throws
2.有返回值,无 throws
3.有返回值,有 throws
不确定会不会出现“无返回值，有throws“的情况。后来真的出现了！依样画葫芦，弄出了这个：
public static <E extends Throwable> void tryCatchException(RunnableException<E> runnable, String serviceName,
String methodName) throws E {
tryCatchException(() -> {
runnable.run();
return null;
}, serviceName, methodName);
}
@FunctionalInterface
public interface RunnableException<E extends Throwable> {
void run() throws E;
}
现在，”人齐了“，拍张全家福：
package com.company.system.util; import java.util.function.Supplier; import org.springframework.beans.factory.BeanCreationException; import com.company.cat.monitor.CatHelper;
import com.company.system.customException.PowerException;
import com.company.system.customException.ServiceException;
import com.company.system.customException.UserException;
import com.company.hyhis.ms.user.custom.exception.MSPowerException;
import com.company.hyhis.ms.user.custom.exception.MSUserException;
import com.company.hyhis.ms.user.custom.exception.MotanCustomException;
import com.weibo.api.motan.exception.MotanAbstractException;
import com.weibo.api.motan.exception.MotanServiceException; public class ThirdParty { public static void tryCatch(Runnable runnable, String serviceName, String methodName) {
tryCatch(() -> {
runnable.run();
return null;
}, serviceName, methodName);
} public static <T> T tryCatch(Supplier<T> supplier, String serviceName, String methodName) {
return tryCatchException(() -> supplier.get(), serviceName, methodName);
} public static <E extends Throwable> void tryCatchException(RunnableException<E> runnable, String serviceName,
String methodName) throws E {
tryCatchException(() -> {
runnable.run();
return null;
}, serviceName, methodName);
} public static <T, E extends Throwable> T tryCatchException(SupplierException<T, E> supplier, String serviceName,
String methodName) throws E {
try {
return supplier.get();
} catch (MotanCustomException ex) {
if (ex.getCode().equals(MSUserException.notLogin().getCode()))
throw UserException.notLogin();
if (ex.getCode().equals(MSPowerException.haveNoPower().getCode()))
throw PowerException.haveNoPower();
throw ex;
} catch (MotanServiceException ex) {
CatHelper.logEventService(serviceName + "-" + methodName, methodName, ex.getStatus(), ex.getErrorCode(),
ex.getMessage());
throw ex;
} catch (MotanAbstractException ex) {
CatHelper.logEventService(serviceName + "-" + methodName, methodName, ex.getStatus(), ex.getErrorCode(),
ex.getMessage());
throw ex;
} catch (Exception ex) {
CatHelper.logError(ex);
throw ex;
}
} @FunctionalInterface
public interface RunnableException<E extends Throwable> {
void run() throws E;
} @FunctionalInterface
public interface SupplierException<T, E extends Throwable> {
T get() throws E;
}
}
