SpringBoot集成PageHelper时出现“在系统中发现了多个分页插件,请检查系统配置!”...

原文链接： http://www.cnblogs.com/jpfss/p/9723828.html

近日在项目中使用SpringBoot集成PageHelper后，跑单元测试时出现了“在系统中发现了多个分页插件,请检查系统配置!”这个问题。

如下图所示：

org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException:

### Error querying database. Cause: java.lang.RuntimeException: 在系统中发现了多个分页插件，请检查系统配置!

### Cause: java.lang.RuntimeException: 在系统中发现了多个分页插件，请检查系统配置!

at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:77)

at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:446)

at com.sun.proxy.$Proxy109.selectList(Unknown Source)

at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:230)

at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:137)

at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:75)

at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:59)

at com.sun.proxy.$Proxy110.selectAll(Unknown Source)

at com.lianjia.cto.ke.broadband.service.StationInfoService.selectPage(StationInfoService.java:27)

at com.lianjia.cto.ke.broadband.service.StationInfoService$$FastClassBySpringCGLIB$$ee2f34a4.invoke()

at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)

at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:738)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)

at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:52)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:168)

at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)

at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:673)

at com.lianjia.cto.ke.broadband.service.StationInfoService$$EnhancerBySpringCGLIB$$1da3a0f3.selectPage()

at com.lianjia.cto.ke.broadband.service.StationInfoServiceTest.selectPage(StationInfoServiceTest.java:27)

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: org.apache.ibatis.exceptions.PersistenceException:

### Error querying database. Cause: java.lang.RuntimeException: 在系统中发现了多个分页插件，请检查系统配置!

### Cause: java.lang.RuntimeException: 在系统中发现了多个分页插件，请检查系统配置!

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 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:433)

... 46 more

Caused by: java.lang.RuntimeException: 在系统中发现了多个分页插件，请检查系统配置!

at com.github.pagehelper.PageHelper.skip(PageHelper.java:55)

at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:92)

at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)

at com.sun.proxy.$Proxy123.query(Unknown Source)

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.Plugin.invoke(Plugin.java:63)

at com.sun.proxy.$Proxy123.query(Unknown Source)

at com.github.pagehelper.PageInterceptor.executeAutoCount(PageInterceptor.java:201)

at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:113)

at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)

at com.sun.proxy.$Proxy123.query(Unknown Source)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)

... 52 more

先上结果：maven的pagehelper-spring-boot-starter这个依赖，提供了自动配置分页插件的功能，所以有两种方法解决这个问题

第一种，SpringBoot启动类的注解上排除这个自动配置

@SpringBootApplication(exclude = PageHelperAutoConfiguration.class)

第二种，在构建SqlSessionFactory时，不要再去手动添加分页的拦截器，在application.yml中进行配置pagehelper的属性，在SpringBoot启动时会将配置自动注入生成拦截器

# PageHelper配置

pagehelper:

offsetAsPageNum: true

rowBoundsWithCount: true

reasonable: true

returnPageInfo: true

params: count=countSql

 

---

以下是解决问题的思路：

看到这个报错后，查看了一下配置，发现并没有配置多个PageHelper。于是查看了一下报错部分的源码，问题出现在一个skip方法中，如下图所示：

public class PageHelper extends PageMethod implements Dialect {

//...

@Override

public boolean skip(MappedStatement ms, Object parameterObject, RowBounds rowBounds) {

//此处的MSUtils.COUNT为一个常量值"_COUNT"

if(ms.getId().endsWith(MSUtils.COUNT)){

throw new RuntimeException("在系统中发现了多个分页插件，请检查系统配置!");

}

//...

}

//...

}

继续向上找，找到了分页插件的拦截器

public class PageInterceptor implements Interceptor {

//...

private String countSuffix = "_COUNT";

@Override

public Object intercept(Invocation invocation) throws Throwable {

try {

//...

//调用方法判断是否需要进行分页，如果不需要，直接返回结果

if (!dialect.skip(ms, parameter, rowBounds)) {

//反射获取动态参数

String msId = ms.getId();

Configuration configuration = ms.getConfiguration();

Map additionalParameters = (Map) additionalParametersField.get(boundSql);

//判断是否需要进行 count 查询

if (dialect.beforeCount(ms, parameter, rowBounds)) {

String countMsId = msId + countSuffix;

Long count;

//先判断是否存在手写的 count 查询

MappedStatement countMs = getExistedMappedStatement(configuration, countMsId);

if(countMs != null){

count = executeManualCount(executor, countMs, parameter, boundSql, resultHandler);

} else {

countMs = msCountMap.get(countMsId);

//自动创建

if (countMs == null) {

//根据当前的 ms 创建一个返回值为 Long 类型的 ms

countMs = MSUtils.newCountMappedStatement(ms, countMsId);

msCountMap.put(countMsId, countMs);

}

count = executeAutoCount(executor, countMs, parameter, boundSql, rowBounds, resultHandler);

}

//处理查询总数

//返回 true 时继续分页查询，false 时直接返回

if (!dialect.afterCount(count, parameter, rowBounds)) {

//当查询总数为 0 时，直接返回空的结果

return dialect.afterPage(new ArrayList(), parameter, rowBounds);

}

}

//判断是否需要进行分页查询

if (dialect.beforePage(ms, parameter, rowBounds)) {

//生成分页的缓存 key

CacheKey pageKey = cacheKey;

//处理参数对象

parameter = dialect.processParameterObject(ms, parameter, boundSql, pageKey);

//调用方言获取分页 sql

String pageSql = dialect.getPageSql(ms, boundSql, parameter, rowBounds, pageKey);

BoundSql pageBoundSql = new BoundSql(configuration, pageSql, boundSql.getParameterMappings(), parameter);

//设置动态参数

for (String key : additionalParameters.keySet()) {

pageBoundSql.setAdditionalParameter(key, additionalParameters.get(key));

}

//执行分页查询

resultList = executor.query(ms, parameter, RowBounds.DEFAULT, resultHandler, pageKey, pageBoundSql);

} else {

//不执行分页的情况下，也不执行内存分页

resultList = executor.query(ms, parameter, RowBounds.DEFAULT, resultHandler, cacheKey, boundSql);

}

} else {

//rowBounds用参数值，不使用分页插件处理时，仍然支持默认的内存分页

resultList = executor.query(ms, parameter, rowBounds, resultHandler, cacheKey, boundSql);

}

return dialect.afterPage(resultList, parameter, rowBounds);

} finally {

dialect.afterAll();

}

}

}

可以发现以_COUNT结尾的MappedStatement.id是由分页插件的拦截器自动生成的，而这个由分页插件的生成之后，怎么会又一次的调用skip方法呢？所以猜测是有多个分页插件的拦截器影响到了。于是查阅了一下相关的资料，发现PageHelper引入了SpringBoot的自动配置，以下是自动配置的源码：

@Configuration

@ConditionalOnBean(SqlSessionFactory.class)

@EnableConfigurationProperties(PageHelperProperties.class)

@AutoConfigureAfter(MybatisAutoConfiguration.class)

public class PageHelperAutoConfiguration {

@Autowired

private List sqlSessionFactoryList;

@Autowired

private PageHelperProperties properties;

/**

* 接受分页插件额外的属性

*

* @return

*/

@Bean

@ConfigurationProperties(prefix = PageHelperProperties.PAGEHELPER_PREFIX)

public Properties pageHelperProperties() {

return new Properties();

}

@PostConstruct

public void addPageInterceptor() {

PageInterceptor interceptor = new PageInterceptor();

Properties properties = new Properties();

//先把一般方式配置的属性放进去

properties.putAll(pageHelperProperties());

//在把特殊配置放进去，由于close-conn 利用上面方式时，属性名就是 close-conn 而不是 closeConn，所以需要额外的一步

properties.putAll(this.properties.getProperties());

interceptor.setProperties(properties);

for (SqlSessionFactory sqlSessionFactory : sqlSessionFactoryList) {

sqlSessionFactory.getConfiguration().addInterceptor(interceptor);

}

}

}

至此，问题算是比较明白了，是因为多个分页拦截器的作用，导致了该异常的出现，所以全局只要保留一个就可以了。

转载于:https://www.cnblogs.com/jpfss/p/9723828.html