【项目报错】com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '5' for key 'PRIMARY'
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:1.8.0_171]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[?:1.8.0_171]
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[?:1.8.0_171]
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[?:1.8.0_171]
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.46.jar:5.1.46]
	at com.mysql.jdbc.Util.getInstance(Util.java:408) ~[mysql-connector-java-5.1.46.jar:5.1.46]
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:936) ~[mysql-connector-java-5.1.46.jar:5.1.46]
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3976) ~[mysql-connector-java-5.1.46.jar:5.1.46]
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3912) ~[mysql-connector-java-5.1.46.jar:5.1.46]
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2530) ~[mysql-connector-java-5.1.46.jar:5.1.46]
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2683) ~[mysql-connector-java-5.1.46.jar:5.1.46]
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2486) ~[mysql-connector-java-5.1.46.jar:5.1.46]
	at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1858) ~[mysql-connector-java-5.1.46.jar:5.1.46]
	at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1197) ~[mysql-connector-java-5.1.46.jar:5.1.46]
	at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_execute(FilterChainImpl.java:3051) ~[druid-1.1.1.jar:1.1.1]
	at com.alibaba.druid.filter.FilterEventAdapter.preparedStatement_execute(FilterEventAdapter.java:440) [druid-1.1.1.jar:1.1.1]
	at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_execute(FilterChainImpl.java:3049) [druid-1.1.1.jar:1.1.1]
	at com.alibaba.druid.wall.WallFilter.preparedStatement_execute(WallFilter.java:601) [druid-1.1.1.jar:1.1.1]
	at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_execute(FilterChainImpl.java:3049) [druid-1.1.1.jar:1.1.1]
	at com.alibaba.druid.filter.FilterEventAdapter.preparedStatement_execute(FilterEventAdapter.java:440) [druid-1.1.1.jar:1.1.1]
	at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_execute(FilterChainImpl.java:3049) [druid-1.1.1.jar:1.1.1]
	at com.alibaba.druid.proxy.jdbc.PreparedStatementProxyImpl.execute(PreparedStatementProxyImpl.java:168) [druid-1.1.1.jar:1.1.1]
	at com.alibaba.druid.pool.DruidPooledPreparedStatement.execute(DruidPooledPreparedStatement.java:494) [druid-1.1.1.jar:1.1.1]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_171]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_171]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_171]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_171]
	at org.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke(PreparedStatementLogger.java:59) [mybatis-3.4.4.jar:3.4.4]
	at com.sun.proxy.$Proxy246.execute(Unknown Source) [?:?]
	at org.apache.ibatis.executor.statement.PreparedStatementHandler.update(PreparedStatementHandler.java:46) [mybatis-3.4.4.jar:3.4.4]
	at org.apache.ibatis.executor.statement.RoutingStatementHandler.update(RoutingStatementHandler.java:74) [mybatis-3.4.4.jar:3.4.4]
	at org.apache.ibatis.executor.ReuseExecutor.doUpdate(ReuseExecutor.java:52) [mybatis-3.4.4.jar:3.4.4]
	at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:117) [mybatis-3.4.4.jar:3.4.4]
	at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:76) [mybatis-3.4.4.jar:3.4.4]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:198) [mybatis-3.4.4.jar:3.4.4]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.insert(DefaultSqlSession.java:185) [mybatis-3.4.4.jar:3.4.4]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_171]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_171]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_171]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_171]
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433) [mybatis-spring-1.3.1.jar:1.3.1]
	at com.sun.proxy.$Proxy153.insert(Unknown Source) [?:?]
	at org.mybatis.spring.SqlSessionTemplate.insert(SqlSessionTemplate.java:278) [mybatis-spring-1.3.1.jar:1.3.1]
	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:57) [mybatis-3.4.4.jar:3.4.4]
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:59) [mybatis-3.4.4.jar:3.4.4]
	at com.sun.proxy.$Proxy197.insertScheduleHisTask(Unknown Source) [?:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_171]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_171]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_171]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_171]

出现这个异常的原因，可能是因为在代码中，对数据库的增删改操作没有考虑事务。

解决方式：添加@Transactional注解。

@Component("xxxServiceImpl")
public class xxxServiceImpl implements xxxService{

    @Override
    @Transactional
    public void doXXX(XXXEntity xxx) {
        // 
        xxxDao.insert(xxx);
    }
}

mysql事务的相关资料可以参考如下几个链接：

https://blog.csdn.net/nextyu/article/details/78669997

https://www.ibm.com/developerworks/cn/java/j-master-spring-transactional-use/index.html

http://www.runoob.com/mysql/mysql-transaction.html