Cause: java.lang.IndexOutOfBoundsException: Index: 5, Size: 5【已解决】

### Error querying database.  Cause: java.lang.IndexOutOfBoundsException: Index: 5, Size: 5
### The error may exist in file [E:\code\security-url\target\classes\mapper\UserMapper.xml]
### The error may involve cn.zhao.url.mapper.UserMapper.getUserByUsername
### The error occurred while handling results
### SQL: select * from user where username = ?;
### Cause: java.lang.IndexOutOfBoundsException: Index: 5, Size: 5
	at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:149) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:76) ~[mybatis-3.5.5.jar:3.5.5]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_202]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_202]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_202]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_202]
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:426) ~[mybatis-spring-2.0.5.jar:2.0.5]
	... 62 common frames omitted
Caused by: java.lang.IndexOutOfBoundsException: Index: 5, Size: 5
	at java.util.ArrayList.rangeCheck(ArrayList.java:657) ~[na:1.8.0_202]
	at java.util.ArrayList.get(ArrayList.java:433) ~[na:1.8.0_202]
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.createUsingConstructor(DefaultResultSetHandler.java:708) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.createByConstructorSignature(DefaultResultSetHandler.java:693) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.createResultObject(DefaultResultSetHandler.java:657) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.createResultObject(DefaultResultSetHandler.java:630) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.getRowValue(DefaultResultSetHandler.java:397) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleRowValuesForSimpleResultMap(DefaultResultSetHandler.java:354) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleRowValues(DefaultResultSetHandler.java:328) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleResultSet(DefaultResultSetHandler.java:301) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleResultSets(DefaultResultSetHandler.java:194) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:65) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:63) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:325) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:89) ~[mybatis-3.5.5.jar:3.5.5]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147) ~[mybatis-3.5.5.jar:3.5.5]
	... 69 common frames omitted

出现上面问题，首先是检查检查mybatis映射的实体类的无参构造写没，出现这种情况一般是无参构造没写，导致mybatis无法对实体类赋值