1、错误信息
在使用JdbcTemplate
查询所有数据时,手动创建了一个JavaBean
对象,然后使用template.query(sql, new BeanPropertyRowMapper<Account>(Account.class))
来查询所有数据。
最后测试,报错信息如下:
org.springframework.beans.TypeMismatchException: Failed to convert property value of type 'null' to required type 'double' for property 'balance'; nested exception is org.springframework.core.convert.ConversionFailedException: Failed to convert from type [null] to type [double] for value 'null'; nested exception is java.lang.IllegalArgumentException: A null value cannot be assigned to a primitive type
at org.springframework.beans.AbstractNestablePropertyAccessor.convertIfNecessary(AbstractNestablePropertyAccessor.java:598)
at org.springframework.beans.AbstractNestablePropertyAccessor.convertForProperty(AbstractNestablePropertyAccessor.java:607)
at org.springframework.beans.AbstractNestablePropertyAccessor.processLocalProperty(AbstractNestablePropertyAccessor.java:456)
at org.springframework.beans.AbstractNestablePropertyAccessor.setPropertyValue(AbstractNestablePropertyAccessor.java:278)
at org.springframework.beans.AbstractNestablePropertyAccessor.setPropertyValue(AbstractNestablePropertyAccessor.java:246)
at org.springframework.jdbc.core.BeanPropertyRowMapper.mapRow(BeanPropertyRowMapper.java:304)
at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:93)
at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:60)
at org.springframework.jdbc.core.JdbcTemplate$1QueryStatementCallback.doInStatement(JdbcTemplate.java:433)
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:375)
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:445)
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:455)
at com.wzq.jdbctemplate.JdbcTemplateDemo02.test6_2(JdbcTemplateDemo02.java:103)
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.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$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: org.springframework.core.convert.ConversionFailedException: Failed to convert from type [null] to type [double] for value 'null'; nested exception is java.lang.IllegalArgumentException: A null value cannot be assigned to a primitive type
at org.springframework.core.convert.support.GenericConversionService.assertNotPrimitiveTargetType(GenericConversionService.java:334)
at org.springframework.core.convert.support.GenericConversionService.handleResult(GenericConversionService.java:327)
at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:183)
at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:280)
at org.springframework.beans.AbstractNestablePropertyAccessor.convertIfNecessary(AbstractNestablePropertyAccessor.java:588)
... 34 more
Caused by: java.lang.IllegalArgumentException: A null value cannot be assigned to a primitive type
... 39 more
2、分析
直接看报错信息的第一句话:
Failed to convert property value of type 'null' to required type 'double' for property 'balance'
翻译一下:对于字段balance
,类型null
转换为double
类型失败了。
应该是JavaBean
中自定义的数据类型错误
3、解决
源代码:
private int id;
private String name;
private double balance;
只需要把int
和double
换成整数和小数的包装类Integer
和Double
就可以了
private Integer id;
private String name;
private Double balance;
最后重新生成get
和set
方法,重新运行:
成功解决