mybatis + maven 搭建入门常见错误

问题

  org.apache.ibatis.exceptions.PersistenceException: 

### Error querying database.  Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for UserMapper.queryUserById

### Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for UserMapper.queryUserById

at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:150)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:77)

at com.mybatis.mapper.UserMapperTest.testQueryUserById(UserMapperTest.java:42)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:606)

at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)

at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)

at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)

at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)

at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)

at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)

at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)

at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)

at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)

at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)

at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)

at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)

at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)

at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)

at org.junit.runners.ParentRunner.run(ParentRunner.java:309)

at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)

at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

Caused by: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for UserMapper.queryUserById

at org.apache.ibatis.session.Configuration$StrictMap.get(Configuration.java:875)

at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:708)

at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:701)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147)

... 30 more

 解决方案

       1. 查看mybatis的核心配置文件是否被加载;

        2. 查看mybatis的映射文件的namespace地址是否和接口对应的类路径是否保持一致;

        3.查看id是否和方法名称保持一致

        4.查看参数类型/返回值类型是否和数据库类型能匹配上

本人的最终解决方案

       pojo类和方法的类型没有匹配上造成的