0x01 fat-jar
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
在使用maven打包的时候，在配置文件加入上面这段配置会开启spring boot的打包。 输入如下：
[INFO] --- spring-boot-maven-plugin:1.5.6.RELEASE:repackage (default) @ kof-logic-server ---
在正常执行maven的打包插件后，Spring-boot会将maven打的包重新进行一次repackage的过程。打成spring boot特有的fat-jar格式。
目录结构大致如下:
BOOT-INF/
classes/
target下的东西
lib/
应用的依赖
META-INF/
MANIFEST.MF
maven/
org/
spring boot loader代码
0x02 spring boot包内的资源加载
现在有这样的需求，maven copy-resources阶段把资源copy到target下，然后在运行时去加载。
使用ClassPathResource是不行的，需要使用UrlResource来加载。demo如下：
public void init() {
beanName2Cfgs = fetch(MAIN_GBEANS_FILE_NAME)
.filter(e -> e.getAttribute("genxml").equals("server"))
.map(this::parseResource)
.filter(r -> r != null)
.map(this::loadResource)
.collect(Collectors.toConcurrentMap(Pair::getKey, Pair::getValue));
if (!isLoadSuccess) {
throw new RuntimeException("ConfigManager加载失败!!！");
}
}
private Stream<Element> fetch(String gbeansName) {
Resource res = newResource(gbeansName);
if (res == null) {
return Stream.empty();
}
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(res.getInputStream());
// load all gbeans
Stream<Element> stream = Stream.empty();
NodeList nl = doc.getElementsByTagName("xi:include");
for (int i = 0; i < nl.getLength(); i++) {
Element e =(Element) nl.item(i);
stream = Stream.concat(fetch(e.getAttribute("href")), stream);
}
// load configuration
XPathFactory xFactory = XPathFactory.newInstance();
XPath xpath = xFactory.newXPath();
Object result = xpath.evaluate("//bean", doc, XPathConstants.NODESET);
nl = (NodeList) result;
for (int i = 0; i < nl.getLength(); i++) {
stream = Stream.concat(Stream.of((Element)nl.item(i)), stream);
}
return stream;
} catch (Exception e) {
LOGGER.error(e.getMessage());
isLoadSuccess = false;
return Stream.empty();
}
}
private Resource parseResource(Element e) {
String fullName = e.getAttribute("name") + ".xml";
Node parent = e.getParentNode();
while (parent != null && parent instanceof Element) {
Element pe = (Element) parent;
fullName = pe.getAttribute("name") + "." + fullName;
parent = parent.getParentNode();
}
fullName = fullName.startsWith(CONFIG_PREFIX) ? fullName : CONFIG_PREFIX + fullName;
return newResource(fullName);
}
private Pair<String, Object> loadResource(Resource res) {
try {
...
return new Pair<String, Object>(key, value);
} catch (Exception e) {
LOGGER.error(e.getMessage());
isLoadSuccess = false;
return new Pair<String, Object>("", "");
}
}
private Resource newResource(String fileName) {
try {
return new UrlResource("classpath:/" + fileName);
} catch (MalformedURLException e) {
LOGGER.error("初始化" + fileName + "的UrlResource时失败！！");
isLoadSuccess = false;
return null;
}
}
上面的demo就是从spring boot fat-jar中的main.xml开始，先遍历出include的所有xml中的bean元素，然后按照一定的规则拼接成文件名，最后再去加载最终资源。
0x03 url的格式
- file:./custom-config/
- classpath:custom-config/
- file:./config/
- file:./
- classpath:/config/
- classpath:/