tomcat 7 源码分析-1 关于读取properties及注册系统properties
tomcat 7 源码分析-1 关于读取properties及注册系统properties

Tomact的启动开始于Bootstrap.java，在其init()中，首先要做的就是

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setCatalinaHome(); setCatalinaBase();initClassLoaders();

?目的就是将tomcat启动的环境设置好，在进行classloader。

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private void setCatalinaHome() { if (System.getProperty("catalina.home") != null) return; File bootstrapJar = new File(System.getProperty("user.dir"), "bootstrap.jar"); if (bootstrapJar.exists()) { try { System.setProperty ("catalina.home", (new File(System.getProperty("user.dir"), "..")) .getCanonicalPath()); } catch (Exception e) { // Ignore System.setProperty("catalina.home", System.getProperty("user.dir")); } } else { System.setProperty("catalina.home", System.getProperty("user.dir")); } }

?判断user.dir\bootstrap.jar存在否来设置catalina.home。

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在initClassLoaders();中调用createClassLoader。loader class之前又要读取properties，于是看String value = CatalinaProperties.getProperty(name + ".loader");

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public class CatalinaProperties { // ------------------------------------------------------- Static Variables private static final org.apache.juli.logging.Log log= org.apache.juli.logging.LogFactory.getLog( CatalinaProperties.class ); private static Properties properties = null; static { loadProperties(); } // --------------------- Public Methods /** * Return specified property value. */ public static String getProperty(String name) { return properties.getProperty(name); } /** * Return specified property value. */ public static String getProperty(String name, String defaultValue) { return properties.getProperty(name, defaultValue); } // --------------------- Public Methods /** * Load properties. */ private static void loadProperties() { InputStream is = null; Throwable error = null; try { String configUrl = getConfigUrl(); if (configUrl != null) { is = (new URL(configUrl)).openStream(); } } catch (Throwable t) { ExceptionUtils.handleThrowable(t); } if (is == null) { try { File home = new File(getCatalinaBase()); File conf = new File(home, "conf"); File properties = new File(conf, "catalina.properties"); is = new FileInputStream(properties); } catch (Throwable t) { ExceptionUtils.handleThrowable(t); } } if (is == null) { try { is = CatalinaProperties.class.getResourceAsStream ("/org/apache/catalina/startup/catalina.properties"); } catch (Throwable t) { ExceptionUtils.handleThrowable(t); } } if (is != null) { try { properties = new Properties(); properties.load(is); is.close(); } catch (Throwable t) { error = t; } } if ((is == null) || (error != null)) { // Do something log.warn("Failed to load catalina.properties", error); // That's fine - we have reasonable defaults. properties=new Properties(); } // Register the properties as system properties Enumeration<?> enumeration = properties.propertyNames(); while (enumeration.hasMoreElements()) { String name = (String) enumeration.nextElement(); String value = properties.getProperty(name); if (value != null) { System.setProperty(name, value); } } } /** * Get the value of the catalina.home environment variable. */ private static String getCatalinaHome() { return System.getProperty("catalina.home", System.getProperty("user.dir")); } /** * Get the value of the catalina.base environment variable. */ private static String getCatalinaBase() { return System.getProperty("catalina.base", getCatalinaHome()); } /** * Get the value of the configuration URL. */ private static String getConfigUrl() { return System.getProperty("catalina.config"); }}

?CatalinaProperties 的核心是静态函数loadProperties()，在这里读取真正意义上的properties并注册