tomcat部署war包

想你了的他他

我们会把工程打成war包部署到tomcat中，然后由容器来对其进行解压，这个过程是怎么样的呢？ 接下来我拉把这个面纱揭开看一下，tomcat源代码如下：1.URL war = new URL("jar:" + (new File(docBase)).toURI().toURL() + "!/");
// Expand the WAR into the new document base directory
JarURLConnection juc = (JarURLConnection) war.openConnection();
juc.setUseCaches(false);
JarFile jarFile = null;
InputStream input = null;
try {
jarFile = juc.getJarFile();
Enumeration jarEntries = jarFile.entries();
while (jarEntries.hasMoreElements()) {
JarEntry jarEntry = (JarEntry) jarEntries.nextElement();
String name = jarEntry.getName();
int last = name.lastIndexOf('/');
if (last >= 0) {
File parent = new File(docBase,
name.substring(0, last));
parent.mkdirs();
}
if (name.endsWith("/")) {
continue;
}
input = jarFile.getInputStream(jarEntry);
// Bugzilla 33636
File expandedFile = expand(input, docBase, name);
long lastModified = jarEntry.getTime();
if ((lastModified != -1) && (lastModified != 0) && (expandedFile != null)) {
expandedFile.setLastModified(lastModified);
}
input.close();
input = null;
}
} catch (IOException e) {
// If something went wrong, delete expanded dir to keep things
// clean
deleteDir(docBase);
throw e;
} finally {
if (input != null) {
try {
input.close();
} catch (Throwable t) {
;
}
input = null;
}
if (jarFile != null) {
try {
jarFile.close();
} catch (Throwable t) {
;
}
jarFile = null;
}
}
2.熟悉tomcat的兄弟都知道，容器在启动的时候其实执行的是两个过程，第一：初始化，第二：启动过程； 而就是在启动HOST的过程中，触发一个start事件，lifecycle.fireLifecycleEvent(START_EVENT, null);
执行到HostConfig类的lifecycleEvent方法中，然后执行start()方法，deployApps方法  —》deployWARs(appBase, appBase.list()); 然后执行到StandardHost的addChild方法  启动StandardContext类的start方法，init方法， fixDocBase()方法，在这个类里会调用ExpandWar.expand(host, war, contextPath);来进行war包的解压,就到此为止，