e.printStackTrace();和log.error()的区别和用法[亲测有效]

catch (Exception e) {
			e.printStackTrace();// 只能输出在控制台当中，日志文件看不到
			System.out.println("--------------------");
			log.error(e.getMessage());// 只能输出简短的错误信息，不便于排错
			System.out.println("--------------------");
			log.error(e.getStackTrace().toString());// 不能输出错误信息
			System.out.println("--------------------");
			log.error("test fail:",e);// 可以在日志中输出完整的错误信息，""里要写内容
			System.out.println("--------------------");
			log.error(e.toString());// 只能输出简短的错误信息，不便于排错
		}
 
// 具体的输出信息可以看下文

org.springframework.jdbc.BadSqlGrammarException: 
### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
### The error may exist in com/cikers/ps/mapper/EquipmentOrderMapper.java (best guess)
### The error may involve com.cikers.ps.mapper.EquipmentOrderMapper.selectByExample-Inline
### The error occurred while setting parameters
### SQL: SELECT id,createdBy,createdOn,modifiedBy,modifiedOn,userId,orderNo,teamId,expressInfoId,distrId,state,procState,sizeRegistrationState,submittedOn,signInTime,paymentState,payedOn,erpMark,tags,price,expireEndTime,deliveredOn,expressNumber,deliveryExpressCompanyId,deliveryExpressCompanyName,warehouseName,warehouseId,attention,source,custBackup,flow,noticeStatus FROM EquipmentOrder WHERE ( awa = ? )
### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
	at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:231)
	at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:73)
	at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:74)
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:421)
	at com.sun.proxy.$Proxy90.selectList(Unknown Source)
	at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:206)
	at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:122)
	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:64)
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:53)
	at com.sun.proxy.$Proxy124.selectByExample(Unknown Source)
	at com.cikers.ps.service.EOrderTest.testException(EOrderTest.java:39)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
	at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
	at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:252)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
	at com.mysql.jdbc.Util.getInstance(Util.java:386)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1054)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4237)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4169)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2617)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2778)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2834)
	at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2156)
	at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1379)
	at com.alibaba.druid.pool.DruidPooledPreparedStatement.execute(DruidPooledPreparedStatement.java:493)
	at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:62)
	at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:78)
	at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:62)
	at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:303)
	at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:154)
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:102)
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:82)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.ibatis.plugin.Invocation.proceed(Invocation.java:49)
	at com.github.pagehelper.SqlUtil._processPage(SqlUtil.java:402)
	at com.github.pagehelper.SqlUtil.processPage(SqlUtil.java:375)
	at com.github.pagehelper.PageHelper.intercept(PageHelper.java:252)
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)
	at com.sun.proxy.$Proxy155.query(Unknown Source)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:120)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:113)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:408)
	... 35 more
--------------------
2019-05-07 14:53:25.229 ERROR 13054 --- [ main] com.cikers.ps.service.EOrderTest : 
### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
### The error may exist in com/cikers/ps/mapper/EquipmentOrderMapper.java (best guess)
### The error may involve com.cikers.ps.mapper.EquipmentOrderMapper.selectByExample-Inline
### The error occurred while setting parameters
### SQL: SELECT id,createdBy,createdOn,modifiedBy,modifiedOn,userId,orderNo,teamId,expressInfoId,distrId,state,procState,sizeRegistrationState,submittedOn,signInTime,paymentState,payedOn,erpMark,tags,price,expireEndTime,deliveredOn,expressNumber,deliveryExpressCompanyId,deliveryExpressCompanyName,warehouseName,warehouseId,attention,source,custBackup,flow,noticeStatus FROM EquipmentOrder WHERE ( awa = ? )
### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
--------------------
2019-05-07 14:53:25.229 ERROR 13054 --- [ main] com.cikers.ps.service.EOrderTest : [Ljava.lang.StackTraceElement;@3c9971af
--------------------
2019-05-07 14:53:25.231 ERROR 13054 --- [ main] com.cikers.ps.service.EOrderTest : test fail:
 
org.springframework.jdbc.BadSqlGrammarException: 
### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
### The error may exist in com/cikers/ps/mapper/EquipmentOrderMapper.java (best guess)
### The error may involve com.cikers.ps.mapper.EquipmentOrderMapper.selectByExample-Inline
### The error occurred while setting parameters
### SQL: SELECT id,createdBy,createdOn,modifiedBy,modifiedOn,userId,orderNo,teamId,expressInfoId,distrId,state,procState,sizeRegistrationState,submittedOn,signInTime,paymentState,payedOn,erpMark,tags,price,expireEndTime,deliveredOn,expressNumber,deliveryExpressCompanyId,deliveryExpressCompanyName,warehouseName,warehouseId,attention,source,custBackup,flow,noticeStatus FROM EquipmentOrder WHERE ( awa = ? )
### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
	at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:231)
	at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:73)
	at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:74)
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:421)
	at com.sun.proxy.$Proxy90.selectList(Unknown Source)
	at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:206)
	at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:122)
	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:64)
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:53)
	at com.sun.proxy.$Proxy124.selectByExample(Unknown Source)
	at com.cikers.ps.service.EOrderTest.testException(EOrderTest.java:39)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
	at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
	at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:252)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
	at com.mysql.jdbc.Util.getInstance(Util.java:386)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1054)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4237)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4169)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2617)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2778)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2834)
	at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2156)
	at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1379)
	at com.alibaba.druid.pool.DruidPooledPreparedStatement.execute(DruidPooledPreparedStatement.java:493)
	at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:62)
	at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:78)
	at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:62)
	at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:303)
	at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:154)
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:102)
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:82)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.ibatis.plugin.Invocation.proceed(Invocation.java:49)
	at com.github.pagehelper.SqlUtil._processPage(SqlUtil.java:402)
	at com.github.pagehelper.SqlUtil.processPage(SqlUtil.java:375)
	at com.github.pagehelper.PageHelper.intercept(PageHelper.java:252)
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)
	at com.sun.proxy.$Proxy155.query(Unknown Source)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:120)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:113)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:408)
	... 35 common frames omitted
 
--------------------
2019-05-07 14:53:25.231 ERROR 13054 --- [ main] com.cikers.ps.service.EOrderTest : org.springframework.jdbc.BadSqlGrammarException: 
### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'
### The error may exist in com/cikers/ps/mapper/EquipmentOrderMapper.java (best guess)
### The error may involve com.cikers.ps.mapper.EquipmentOrderMapper.selectByExample-Inline
### The error occurred while setting parameters
### SQL: SELECT id,createdBy,createdOn,modifiedBy,modifiedOn,userId,orderNo,teamId,expressInfoId,distrId,state,procState,sizeRegistrationState,submittedOn,signInTime,paymentState,payedOn,erpMark,tags,price,expireEndTime,deliveredOn,expressNumber,deliveryExpressCompanyId,deliveryExpressCompanyName,warehouseName,warehouseId,attention,source,custBackup,flow,noticeStatus FROM EquipmentOrder WHERE ( awa = ? )
### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'awa' in 'where clause'

关于e.printStackTrace();可能造成死锁的文章见https://my.oschina.net/sxgkwei/blog/825700。。最好不要在生产代码中出现e.printStackTrace()，一是不容易排错，二是容易造成死锁。

采用不同的log.error()来输出想要的结果。