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.SqlSessionFactoryBean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Service;
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;
/**
* @author: chenglongyi
**/
@Service
public class MapperHotDeployPlugin implements InitializingBean, ApplicationContextAware {
private final static Logger logger = LoggerFactory.getLogger(MapperHotDeployPlugin.class);
private final static String OPEN = "1";
private volatile SqlSessionFactoryBean sqlSessionFactoryBean;
private volatile Configuration configuration;
@Override
public void afterPropertiesSet() {
String flag = "true";
logger.info("Mybatis热部署标识mapper.hot.deploy={}", flag);
// 判断是否开启了热部署
if (OPEN.equals(flag)) {
new WatchThread().start();
}
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
sqlSessionFactoryBean = (SqlSessionFactoryBean) applicationContext.getBean("&sqlSessionFactoryMybatis");
SqlSessionFactory sqlSessionFactory = null;
try {
sqlSessionFactory = sqlSessionFactoryBean.getObject();
} catch (Exception e) {
logger.error(e.getMessage(), e);
}
configuration = sqlSessionFactory.getConfiguration();
}
class WatchThread extends Thread {
private final Logger logger = LoggerFactory.getLogger(WatchThread.class);
@Override
public void run() {
startWatch();
}
/**
* 启动监听
*
* @date ：2018/12/19
* @author ：zc.ding@foxmail.com
*/
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
*
* @return java.util.Set<java.lang.String>
* @date ：2018/12/19
* @author ：zc.ding@foxmail.com
*/
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
*
* @return org.springframework.core.io.Resource[]
* @date ：2018/12/19
* @author ：zc.ding@foxmail.com
*/
private Resource[] getResource() {
return (Resource[]) getFieldValue(sqlSessionFactoryBean, "mapperLocations");
}
/**
* 删除xml元素的节点缓存
*
* @param nameSpace xml中命名空间
* @date ：2018/12/19
* @author ：zc.ding@foxmail.com
*/
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
*
* @param resource xml文件路径
* @date ：2018/12/19
* @author ：zc.ding@foxmail.com
*/
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
* @return java.lang.Object
* @date ：2018/12/19
* @author ：zc.ding@foxmail.com
*/
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
* @date ：2018/12/19
* @author ：zc.ding@foxmail.com
*/
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
* @return java.lang.String
* @date ：2018/12/19
* @author ：zc.ding@foxmail.com
*/
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);
}
}
}
}
