Spring Boot 项目访问依赖 jar 包内部的资源文件的路径问题详解
核心代码行:
Resource[]resources =new PathMatchingResourcePatternResolver().getResources(ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX +"META-INF/driver.properties");
直接上源码:
package com.bytedance.kunlun.engine.drivermanager;
import java.io.InputStream;
import java.net.URL;
import java.util.*;
import com.bytedance.kunlun.sdk.drivermanager.api.Driver;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
public class KunLunDriverManager {
/**
* 注册进系统的驱动列表
*/
private final static MapregisteredDrivers =new HashMap<>();
/**
* 驱动配置，配置文件名
*/
private static final String DRIVER_PROPS_FILE ="META-INF/driver.properties";
/**
* 驱动配置Key，Driver实现class全名
*/
private static final String KEY_DRIVER_IMPL ="driver_class_name";
/**
* 驱动配置Key，Driver名称
*/
private static final String KEY_DRIVER_NAME ="driver_name";
/**
* 防止类显示初始化调用
*/
private KunLunDriverManager() {
}
static {
try {
loadInitialDrivers();
}catch (Exception e) {
throw new RuntimeException(e);
}
}
public static Driver getDriver(String driverName) {
return registeredDrivers.get(driverName);
}
/**
* 注入driver
*/
private static void registerDriver(String driverName,Driver driver)throws Exception {
if (registeredDrivers.containsKey(driverName)) {
throw new Exception("引擎名称重复");
}
registeredDrivers.put(driverName, driver);
}
/**
* 扫classpath下的所有DRIVER_PROPS_FILE文件，反射实例化，注入DriverManager
*/
private static void loadInitialDrivers()throws Exception {
Resource[]resources =new PathMatchingResourcePatternResolver().getResources(ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX +"META-INF/driver.properties");
for (int i =0; i
Resource res =resources[i];
URL url =res.getURL();
InputStream in =url.openStream();
Properties props =new Properties();
props.load(in);
// 通过反射 new driver instance
Driver driver =newDriverByParseProperties(props);
if (driver !=null) {
registerDriver(props.getProperty(KEY_DRIVER_NAME),driver);
}
}
}
/**
* 根据Properties配置反射生成Driver
*/
private static Driver newDriverByParseProperties(Properties props)throws Exception {
Classclazz =Class.forName(props.getProperty(KEY_DRIVER_IMPL));
Driver driver = (Driver)clazz.getDeclaredConstructor().newInstance();
return driver.setUp(props);
}
}
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