什么 JRebel 热部署失效? 多数据源分页失效?
- 上一次有讲到配置多数据源,但就在此时我的JRebel热部署失效了,但也不是完全失效,更改代码可以实现热部署,可是编写xml改变sql 就不会生效,不能热部署就要重启项目,由于项目太大启动就要2分钟,这效率可太慢了!
怎么办?,那就自己写个xml 等资源文件的热部署吧.
1. 编写代码
package com.ym.web.config.mybatis;
import org.apache.ibatis.builder.xml.XMLMapperBuilder;
import org.apache.ibatis.builder.xml.XMLMapperEntityResolver;
import org.apache.ibatis.executor.ErrorContext;
import org.apache.ibatis.parsing.XPathParser;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.boot.autoconfigure.MybatisProperties;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Component;
import java.lang.reflect.Field;
import java.nio.file.FileSystems;
import java.nio.file.Paths;
import java.nio.file.StandardWatchEventKinds;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;
/**
* mybatis热部署插件
* 设置mybatis配置文件cache-enabled: false不缓存，开启热部署xml
*
* @author:
* @version: 2021年03月28日 14:10
*/
@Component
public class MapperHotDeployPlugin implements InitializingBean, ApplicationContextAware {
private final static Logger logger = LoggerFactory.getLogger(MapperHotDeployPlugin.class);
@Autowired
private MybatisProperties mybatisProperties;
private Configuration configuration;
@Override
public void afterPropertiesSet() {
// 设置mybatis配置文件cache-enabled: false不缓存，开启热部署xml
if (!mybatisProperties.getConfiguration().isCacheEnabled()) {
new WatchThread().start();
logger.info("热部署开启{}",mybatisProperties);
}
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
SqlSessionFactory sqlSessionFactory = (SqlSessionFactory) applicationContext.getBean("ds1SqlSessionFactory");
configuration = sqlSessionFactory.getConfiguration();
logger.info("setApplicationContext{},{}",sqlSessionFactory,configuration);
System.out.println();
}
class WatchThread extends Thread {
private final Logger logger = LoggerFactory.getLogger(WatchThread.class);
@Override
public void run() {
startWatch();
}
/**
* 启动监听
*/
private void startWatch() {
try {
WatchService watcher = FileSystems.getDefault().newWatchService();
getWatchPaths().forEach(p -> {
try {
Paths.get(p).register(watcher, StandardWatchEventKinds.ENTRY_MODIFY);
} catch (Exception e) {
logger.error("ERROR: 注册xml监听事件", e);
throw new RuntimeException("ERROR: 注册xml监听事件", e);
}
});
while (true) {
WatchKey watchKey = watcher.take();
Set<String> set = new HashSet<>();
for (WatchEvent<?> event : watchKey.pollEvents()) {
set.add(event.context().toString());
}
// 重新加载xml
reloadXml(set);
boolean valid = watchKey.reset();
if (!valid) {
break;
}
}
} catch (Exception e) {
System.out.println("Mybatis的xml监控失败!");
logger.info("Mybatis的xml监控失败!", e);
}
}
/**
* 加载需要监控的文件父路径
*/
private Set<String> getWatchPaths() {
Set<String> set = new HashSet<>();
Arrays.stream(getResource()).forEach(r -> {
try {
logger.info("资源路径:{}", r.toString());
set.add(r.getFile().getParentFile().getAbsolutePath());
} catch (Exception e) {
logger.info("获取资源路径失败", e);
throw new RuntimeException("获取资源路径失败");
}
});
logger.info("需要监听的xml资源: {}", set);
return set;
}
/**
* 获取配置的mapperLocations
*/
private Resource[] getResource() {
return mybatisProperties.resolveMapperLocations();
}
/**
* 删除xml元素的节点缓存
* "mappedStatements",
*/
private void clearMap(String nameSpace) {
logger.info("清理Mybatis的namespace={}在mappedStatements、caches、resultMaps、parameterMaps、keyGenerators、sqlFragments中的缓存");
Arrays.asList("mappedStatements" ,"caches", "resultMaps", "parameterMaps", "keyGenerators", "sqlFragments").forEach(fieldName -> {
Object value = getFieldValue(configuration, fieldName);
if (value instanceof Map) {
Map<?, ?> map = (Map) value;
List<Object> list = map.keySet().stream().filter(o -> o.toString().startsWith(nameSpace + ".")).collect(Collectors.toList());
logger.info("需要清理的元素: {}", list);
list.forEach(k -> map.remove((Object) k));
}
});
}
/**
* 清除文件记录缓存
*/
private void clearSet(String resource) {
logger.info("清理mybatis的资源{}在容器中的缓存", resource);
Object value = getFieldValue(configuration, "loadedResources");
if (value instanceof Set) {
Set<?> set = (Set) value;
set.remove(resource);
set.remove("namespace:" + resource);
}
}
/**
* 获取对象指定属性
*
* @param obj 对象信息
* @param fieldName 属性名称
*/
private Object getFieldValue(Object obj, String fieldName) {
logger.info("从{}中加载{}属性", obj, fieldName);
try {
Field field = obj.getClass().getDeclaredField(fieldName);
boolean accessible = field.isAccessible();
field.setAccessible(true);
Object value = field.get(obj);
field.setAccessible(accessible);
return value;
} catch (Exception e) {
logger.info("ERROR: 加载对象中[{}]", fieldName, e);
throw new RuntimeException("ERROR: 加载对象中[" + fieldName + "]", e);
}
}
/**
* 重新加载set中xml
*
* @param set 修改的xml资源
*/
private void reloadXml(Set<String> set) {
logger.info("需要重新加载的文件列表: {}", set);
List<Resource> list = Arrays.stream(getResource())
.filter(p -> set.contains(p.getFilename()))
.collect(Collectors.toList());
logger.info("需要处理的资源路径:{}", list);
list.forEach(r -> {
try {
clearMap(getNamespace(r));
clearSet(r.toString());
XMLMapperBuilder xmlMapperBuilder = new XMLMapperBuilder(r.getInputStream(), configuration,
r.toString(), configuration.getSqlFragments());
xmlMapperBuilder.parse();
} catch (Exception e) {
logger.info("ERROR: 重新加载[{}]失败", r.toString(), e);
throw new RuntimeException("ERROR: 重新加载[" + r.toString() + "]失败", e);
} finally {
ErrorContext.instance().reset();
}
});
logger.info("成功热部署文件列表: {}", set);
}
/**
* 获取xml的namespace
*
* @param resource xml资源
*/
private String getNamespace(Resource resource) {
logger.info("从{}获取namespace", resource.toString());
try {
XPathParser parser = new XPathParser(resource.getInputStream(), true, null, new XMLMapperEntityResolver());
return parser.evalNode("/mapper").getStringAttribute("namespace");
} catch (Exception e) {
logger.info("ERROR: 解析xml中namespace失败", e);
throw new RuntimeException("ERROR: 解析xml中namespace失败", e);
}
}
}
}
实话说 网上百度也有源代码 但是对于我配置的多数据源来说 些许不同
问题点1. 我的多数据源原来的是MybatisSqlSessionFactory 把这里改成 SqlSessionFactory 后问题就来了
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
SqlSessionFactory sqlSessionFactory = (SqlSessionFactory) applicationContext.getBean("ds1SqlSessionFactory");
configuration = sqlSessionFactory.getConfiguration();
logger.info("setApplicationContext{},{}",sqlSessionFactory,configuration);
System.out.println();
}
报错
java.lang.RuntimeException: 在系统中发现了多个分页插件,请检查系统配置!
原因: SqlSessionFactory 自动注入了PageHelper 也就是分页插件
分析源码:
/**
* 自定注入分页插件
*
* @author liuzh
*/
@Configuration
@ConditionalOnBean(SqlSessionFactory.class)
@EnableConfigurationProperties(PageHelperProperties.class)
@AutoConfigureAfter(MybatisAutoConfiguration.class)
public class PageHelperAutoConfiguration {
//这里是所有的数据源 并都注入分页插件 问题点就在这
@Autowired
private List<SqlSessionFactory> 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);
}
}
}
@Configuration 配置类
@ConditionalOnBean(SqlSessionFactory.class) 装配条件该类装配完成
@EnableConfigurationProperties(PageHelperProperties.class) 自动装配
@AutoConfigureAfter(MybatisAutoConfiguration.class) ==最后装配 ==
配置类无疑
//获取了所有sqlSessionFactoryList,多数据源就注入了两次
private List sqlSessionFactoryList;
问题找到了 ,既然多次注入 那就不要让他注入我们手动注入
1. 在SpringApplication 入口取消分页自动注入
@EnableAutoConfiguration(exclude= PageHelperAutoConfiguration.class)
2.编写手动注入分页bean交给spring
package com.ym.web.config.datasource;
import com.github.pagehelper.PageInterceptor;
import com.github.pagehelper.autoconfigure.PageHelperProperties;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;
import java.util.Properties;
/**
* @Author wenbo
* @Date 2021/3/25 19:05
**/
@Component
public class MybatisPageInterceptor {
/**
* 接受分页插件额外的属性
*
* @return
*/
@Bean
@ConfigurationProperties(prefix = PageHelperProperties.PAGEHELPER_PREFIX)
public Properties pageHelperProperties() {
return new Properties();
}
/**
* 配置插件
*
* @return bean
*/
@Bean(name = "pagePlugin")
public PageInterceptor pageInterceptor() {
//org.apache.ibatis.plugin.Interceptor
PageInterceptor interceptor = new PageInterceptor();
//java.util.Properties
Properties properties = new Properties();
properties.putAll(pageHelperProperties());
//properties.putAll(this.properties.getProperties());
// 是否返回行数，相当于MySQL的count(*)
//properties.setProperty("rowBoundsWithCount", "true");
interceptor.setProperties(properties);
return interceptor;
}
}
3.在每个数据源中手动加入到 mybatis的拦截器
configuration.addInterceptor(pageInterceptor.pageInterceptor());
数据源1
@Autowired
private MybatisPageInterceptor pageInterceptor;
/**
* 主数据源 ds1数据源
* @return
* @throws Exception
*/
@Primary
@Bean("ds1SqlSessionFactory")
@DependsOn("pagePlugin")
public SqlSessionFactory ds1SqlSessionFactory(@Qualifier("ds1SqlSessionFactoryBean") SqlSessionFactoryBean sqlSessionFactoryBean) throws Exception {
//sqlSessionFactoryBean.setPlugins(plugins ());
SqlSessionFactory sqlSessionFactor = sqlSessionFactoryBean.getObject();
org.apache.ibatis.session.Configuration configuration = sqlSessionFactor.getConfiguration();
configuration.addInterceptor(pageInterceptor.pageInterceptor());
configuration.setMapUnderscoreToCamelCase(true);
return sqlSessionFactoryBean.getObject();
}
4.数据源2相同操作
然后测试分页两个数据源都生效了 热部署也生效了
重点: 如果使用 MybatisSqlSessionFactory 就不会有多个分页这种错误 这无疑是一种快捷方式!!
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