tomcat源码浅析（三）之webapps的解析

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1.HostConfig在start中会调用deployApps方法扫描appBase目录下的apps，加载DocBase/META-INF/context.xml.

Hostconfig.deployapps代码

1. protected void deployApps() {  
2.   
3.         File appBase = appBase();  
4.         File configBase = configBase();  
5.         String[] filteredAppPaths = filterAppPaths(appBase.list());  
6.         // Deploy XML descriptors from configBase  
7.         deployDescriptors(configBase, configBase.list());  
8.         // Deploy WARs  
9.         deployWARs(appBase, filteredAppPaths);  
10.         // Deploy expanded folders  
11.         deployDirectories(appBase, filteredAppPaths);  
12.   
13.     }  

Hostconfig.deploydescriptor代码

1. protected void deployDescriptor(ContextName cn, File contextXml) {  
2.   
3.         DeployedApplication deployedApp =  
4.                 new DeployedApplication(cn.getName(), true);  
5.   
6.         long startTime = 0;  
7.         // Assume this is a configuration descriptor and deploy it  
8.         if(log.isInfoEnabled()) {  
9.            startTime = System.currentTimeMillis();  
10.            log.info(sm.getString("hostConfig.deployDescriptor",  
11.                     contextXml.getAbsolutePath()));  
12.         }  
13.   
14.         Context context = null;  
15.         boolean isExternalWar = false;  
16.         boolean isExternal = false;  
17.         File expandedDocBase = null;  
18.         FileInputStream fis = null;  
19.         try {  
20.             fis = new FileInputStream(contextXml);  
21.             synchronized (digesterLock) {  
22.                 try {  
23.                     context = (Context) digester.parse(fis);  
24.                 } catch (Exception e) {  
25.                     log.error(sm.getString(  
26.                             "hostConfig.deployDescriptor.error",  
27.                             contextXml.getAbsolutePath()), e);  
28.                     context = new FailedContext();  
29.                 } finally {  
30.                     digester.reset();  
31.                 }  
32.             }  
33.   
34.             Class<?> clazz = Class.forName(host.getConfigClass());  
35.             LifecycleListener listener =  
36.                 (LifecycleListener) clazz.newInstance();  
37.             context.addLifecycleListener(listener);  
38.   
39.             context.setConfigFile(contextXml.toURI().toURL());  
40.             context.setName(cn.getName());  
41.             context.setPath(cn.getPath());  
42.             context.setWebappVersion(cn.getVersion());  
43.             // Add the associated docBase to the redeployed list if it's a WAR  
44.             if (context.getDocBase() != null) {  
45.                 File docBase = new File(context.getDocBase());  
46.                 if (!docBase.isAbsolute()) {  
47.                     docBase = new File(appBase(), context.getDocBase());  
48.                 }  
49.                 // If external docBase, register .xml as redeploy first  
50.                 if (!docBase.getCanonicalPath().startsWith(  
51.                         appBase().getAbsolutePath() + File.separator)) {  
52.                     isExternal = true;  
53.                     deployedApp.redeployResources.put(  
54.                             contextXml.getAbsolutePath(),  
55.                             Long.valueOf(contextXml.lastModified()));  
56.                     deployedApp.redeployResources.put(docBase.getAbsolutePath(),  
57.                             Long.valueOf(docBase.lastModified()));  
58.                     if (docBase.getAbsolutePath().toLowerCase(Locale.ENGLISH).endsWith(".war")) {  
59.                         isExternalWar = true;  
60.                     }  
61.                 } else {  
62.                     log.warn(sm.getString("hostConfig.deployDescriptor.localDocBaseSpecified",  
63.                              docBase));  
64.                     // Ignore specified docBase  
65.                     context.setDocBase(null);  
66.                 }  
67.             }  
68.   
69.             host.addChild(context);  
70.         } catch (Throwable t) {  
71.             ExceptionUtils.handleThrowable(t);  
72.             log.error(sm.getString("hostConfig.deployDescriptor.error",  
73.                                    contextXml.getAbsolutePath()), t);  
74.         } finally {  
75.             if (fis != null) {  
76.                 try {  
77.                     fis.close();  
78.                 } catch (IOException e) {  
79.                     // Ignore  
80.                 }  
81.             }  
82.             // Get paths for WAR and expanded WAR in appBase  
83.   
84.             // default to appBase dir + name  
85.             expandedDocBase = new File(appBase(), cn.getBaseName());  
86.             if (context.getDocBase() != null  
87.                     && !context.getDocBase().toLowerCase(Locale.ENGLISH).endsWith(".war")) {  
88.                 // first assume docBase is absolute  
89.                 expandedDocBase = new File(context.getDocBase());  
90.                 if (!expandedDocBase.isAbsolute()) {  
91.                     // if docBase specified and relative, it must be relative to appBase  
92.                     expandedDocBase = new File(appBase(), context.getDocBase());  
93.                 }  
94.             }  
95.   
96.             boolean unpackWAR = unpackWARs;  
97.             if (unpackWAR && context instanceof StandardContext) {  
98.                 unpackWAR = ((StandardContext) context).getUnpackWAR();  
99.             }  
100.   
101.             // Add the eventual unpacked WAR and all the resources which will be  
102.             // watched inside it  
103.             if (isExternalWar) {  
104.                 if (unpackWAR) {  
105.                     deployedApp.redeployResources.put(expandedDocBase.getAbsolutePath(),  
106.                             Long.valueOf(expandedDocBase.lastModified()));  
107.                     addWatchedResources(deployedApp, expandedDocBase.getAbsolutePath(), context);  
108.                 } else {  
109.                     addWatchedResources(deployedApp, null, context);  
110.                 }  
111.             } else {  
112.                 // Find an existing matching war and expanded folder  
113.                 if (!isExternal) {  
114.                     File warDocBase = new File(expandedDocBase.getAbsolutePath() + ".war");  
115.                     if (warDocBase.exists()) {  
116.                         deployedApp.redeployResources.put(warDocBase.getAbsolutePath(),  
117.                                 Long.valueOf(warDocBase.lastModified()));  
118.                     } else {  
119.                         // Trigger a redeploy if a WAR is added  
120.                         deployedApp.redeployResources.put(  
121.                                 warDocBase.getAbsolutePath(),  
122.                                 Long.valueOf(0));  
123.                     }  
124.                 }  
125.                 if (unpackWAR) {  
126.                     deployedApp.redeployResources.put(expandedDocBase.getAbsolutePath(),  
127.                             Long.valueOf(expandedDocBase.lastModified()));  
128.                     addWatchedResources(deployedApp,  
129.                             expandedDocBase.getAbsolutePath(), context);  
130.                 } else {  
131.                     addWatchedResources(deployedApp, null, context);  
132.                 }  
133.                 if (!isExternal) {  
134.                     // For external docBases, the context.xml will have been  
135.                     // added above.  
136.                     deployedApp.redeployResources.put(  
137.                             contextXml.getAbsolutePath(),  
138.                             Long.valueOf(contextXml.lastModified()));  
139.                 }  
140.             }  
141.             // Add the global redeploy resources (which are never deleted) at  
142.             // the end so they don't interfere with the deletion process  
143.             addGlobalRedeployResources(deployedApp);  
144.         }  
145.   
146.         if (host.findChild(context.getName()) != null) {  
147.             deployed.put(context.getName(), deployedApp);  
148.         }  
149.   
150.         if (log.isInfoEnabled()) {  
151.             log.info(sm.getString("hostConfig.deployDescriptor.finished",  
152.                 contextXml.getAbsolutePath(), Long.valueOf(System.currentTimeMillis() - startTime)));  
153.         }  
154.     }  

Hostconfig.deploywar代码

1. protected void deployWAR(ContextName cn, File war) {  
2.   
3.        // Checking for a nested /META-INF/context.xml  
4.        JarFile jar = null;  
5.        InputStream istream = null;  
6.        FileOutputStream fos = null;  
7.        BufferedOutputStream ostream = null;  
8.   
9.        File xml = new File(appBase(),  
10.                cn.getBaseName() + "/META-INF/context.xml");  
11.   
12.        boolean xmlInWar = false;  
13.        try {  
14.            jar = new JarFile(war);  
15.            JarEntry entry = jar.getJarEntry(Constants.ApplicationContextXml);  
16.            if (entry != null) {  
17.                xmlInWar = true;  
18.            }  
19.        } catch (IOException e) {  
20.            /* Ignore */  
21.        } finally {  
22.            if (jar != null) {  
23.                try {  
24.                    jar.close();  
25.                } catch (IOException ioe) {  
26.                    // Ignore;  
27.                }  
28.                jar = null;  
29.            }  
30.        }  
31.   
32.        Context context = null;  
33.        try {  
34.            if (deployXML && xml.exists() && unpackWARs && !copyXML) {  
35.                synchronized (digesterLock) {  
36.                    try {  
37.                        context = (Context) digester.parse(xml);  
38.                    } catch (Exception e) {  
39.                        log.error(sm.getString(  
40.                                "hostConfig.deployDescriptor.error",  
41.                                war.getAbsolutePath()), e);  
42.                    } finally {  
43.                        digester.reset();  
44.                        if (context == null) {  
45.                            context = new FailedContext();  
46.                        }  
47.                    }  
48.                }  
49.                context.setConfigFile(xml.toURI().toURL());  
50.            } else if (deployXML && xmlInWar) {  
51.                synchronized (digesterLock) {  
52.                    try {  
53.                        jar = new JarFile(war);  
54.                        JarEntry entry =  
55.                            jar.getJarEntry(Constants.ApplicationContextXml);  
56.                        istream = jar.getInputStream(entry);  
57.                        context = (Context) digester.parse(istream);  
58.                    } catch (Exception e) {  
59.                        log.error(sm.getString(  
60.                                "hostConfig.deployDescriptor.error",  
61.                                war.getAbsolutePath()), e);  
62.                    } finally {  
63.                        digester.reset();  
64.                        if (istream != null) {  
65.                            try {  
66.                                istream.close();  
67.                            } catch (IOException e) {  
68.                                /* Ignore */  
69.                            }  
70.                            istream = null;  
71.                        }  
72.                        if (jar != null) {  
73.                            try {  
74.                                jar.close();  
75.                            } catch (IOException e) {  
76.                                /* Ignore */  
77.                            }  
78.                            jar = null;  
79.                        }  
80.                        if (context == null) {  
81.                            context = new FailedContext();  
82.                        }  
83.                        context.setConfigFile(  
84.                                UriUtil.buildJarUrl(war, Constants.ApplicationContextXml));  
85.                    }  
86.                }  
87.            } else if (!deployXML && xmlInWar) {  
88.                // Block deployment as META-INF/context.xml may contain security  
89.                // configuration necessary for a secure deployment.  
90.                log.error(sm.getString("hostConfig.deployDescriptor.blocked",  
91.                        cn.getPath(), Constants.ApplicationContextXml,  
92.                        new File(configBase(), cn.getBaseName() + ".xml")));  
93.            } else {  
94.                context = (Context) Class.forName(contextClass).newInstance();  
95.            }  
96.        } catch (Throwable t) {  
97.            ExceptionUtils.handleThrowable(t);  
98.            log.error(sm.getString("hostConfig.deployWar.error",  
99.                    war.getAbsolutePath()), t);  
100.        } finally {  
101.            if (context == null) {  
102.                context = new FailedContext();  
103.            }  
104.        }  
105.   
106.        boolean copyThisXml = false;  
107.        if (deployXML) {  
108.            if (host instanceof StandardHost) {  
109.                copyThisXml = ((StandardHost) host).isCopyXML();  
110.            }  
111.   
112.            // If Host is using default value Context can override it.  
113.            if (!copyThisXml && context instanceof StandardContext) {  
114.                copyThisXml = ((StandardContext) context).getCopyXML();  
115.            }  
116.   
117.            if (xmlInWar && copyThisXml) {  
118.                // Change location of XML file to config base  
119.                xml = new File(configBase(), cn.getBaseName() + ".xml");  
120.                try {  
121.                    jar = new JarFile(war);  
122.                    JarEntry entry =  
123.                        jar.getJarEntry(Constants.ApplicationContextXml);  
124.                    istream = jar.getInputStream(entry);  
125.   
126.                    fos = new FileOutputStream(xml);  
127.                    ostream = new BufferedOutputStream(fos, 1024);  
128.                    byte buffer[] = new byte[1024];  
129.                    while (true) {  
130.                        int n = istream.read(buffer);  
131.                        if (n < 0) {  
132.                            break;  
133.                        }  
134.                        ostream.write(buffer, 0, n);  
135.                    }  
136.                    ostream.flush();  
137.                } catch (IOException e) {  
138.                    /* Ignore */  
139.                } finally {  
140.                    if (ostream != null) {  
141.                        try {  
142.                            ostream.close();  
143.                        } catch (IOException ioe) {  
144.                            // Ignore  
145.                        }  
146.                        ostream = null;  
147.                    }  
148.                    if (fos != null) {  
149.                        try {  
150.                            fos.close();  
151.                        } catch (IOException ioe) {  
152.                            // Ignore  
153.                        }  
154.                        fos = null;  
155.                    }  
156.                    if (istream != null) {  
157.                        try {  
158.                            istream.close();  
159.                        } catch (IOException ioe) {  
160.                            // Ignore  
161.                        }  
162.                        istream = null;  
163.                    }  
164.                    if (jar != null) {  
165.                        try {  
166.                            jar.close();  
167.                        } catch (IOException ioe) {  
168.                            // Ignore;  
169.                        }  
170.                        jar = null;  
171.                    }  
172.                }  
173.            }  
174.        }  
175.   
176.        DeployedApplication deployedApp = new DeployedApplication(cn.getName(),  
177.                xml.exists() && deployXML && copyThisXml);  
178.   
179.        long startTime = 0;  
180.        // Deploy the application in this WAR file  
181.        if(log.isInfoEnabled()) {  
182.            startTime = System.currentTimeMillis();  
183.            log.info(sm.getString("hostConfig.deployWar",  
184.                    war.getAbsolutePath()));  
185.        }  
186.   
187.        try {  
188.            // Populate redeploy resources with the WAR file  
189.            deployedApp.redeployResources.put  
190.                (war.getAbsolutePath(), Long.valueOf(war.lastModified()));  
191.   
192.            if (deployXML && xml.exists() && copyThisXml) {  
193.                deployedApp.redeployResources.put(xml.getAbsolutePath(),  
194.                        Long.valueOf(xml.lastModified()));  
195.            } else {  
196.                // In case an XML file is added to the config base later  
197.                deployedApp.redeployResources.put(  
198.                        (new File(configBase(),  
199.                                cn.getBaseName() + ".xml")).getAbsolutePath(),  
200.                        Long.valueOf(0));  
201.            }  
202.   
203.            Class<?> clazz = Class.forName(host.getConfigClass());  
204.            LifecycleListener listener =  
205.                (LifecycleListener) clazz.newInstance();  
206.            context.addLifecycleListener(listener);  
207.   
208.            context.setName(cn.getName());  
209.            context.setPath(cn.getPath());  
210.            context.setWebappVersion(cn.getVersion());  
211.            context.setDocBase(cn.getBaseName() + ".war");  
212.            host.addChild(context);  
213.        } catch (Throwable t) {  
214.            ExceptionUtils.handleThrowable(t);  
215.            log.error(sm.getString("hostConfig.deployWar.error",  
216.                    war.getAbsolutePath()), t);  
217.        } finally {  
218.            // If we're unpacking WARs, the docBase will be mutated after  
219.            // starting the context  
220.            boolean unpackWAR = unpackWARs;  
221.            if (unpackWAR && context instanceof StandardContext) {  
222.                unpackWAR = ((StandardContext) context).getUnpackWAR();  
223.            }  
224.            if (unpackWAR && context.getDocBase() != null) {  
225.                File docBase = new File(appBase(), cn.getBaseName());  
226.                deployedApp.redeployResources.put(docBase.getAbsolutePath(),  
227.                        Long.valueOf(docBase.lastModified()));  
228.                addWatchedResources(deployedApp, docBase.getAbsolutePath(),  
229.                        context);  
230.                if (deployXML && !copyThisXml && (xmlInWar || xml.exists())) {  
231.                    deployedApp.redeployResources.put(xml.getAbsolutePath(),  
232.                            Long.valueOf(xml.lastModified()));  
233.                }  
234.            } else {  
235.                // Passing null for docBase means that no resources will be  
236.                // watched. This will be logged at debug level.  
237.                addWatchedResources(deployedApp, null, context);  
238.            }  
239.            // Add the global redeploy resources (which are never deleted) at  
240.            // the end so they don't interfere with the deletion process  
241.            addGlobalRedeployResources(deployedApp);  
242.        }  
243.   
244.        deployed.put(cn.getName(), deployedApp);  
245.   
246.        if (log.isInfoEnabled()) {  
247.            log.info(sm.getString("hostConfig.deployWar.finished",  
248.                war.getAbsolutePath(), Long.valueOf(System.currentTimeMillis() - startTime)));  
249.        }  
250.    }  

Hostconfig.deploydescriptor代码

1. protected void deployDescriptor(ContextName cn, File contextXml) {  
2.   
3.         DeployedApplication deployedApp =  
4.                 new DeployedApplication(cn.getName(), true);  
5.   
6.         long startTime = 0;  
7.         // Assume this is a configuration descriptor and deploy it  
8.         if(log.isInfoEnabled()) {  
9.            startTime = System.currentTimeMillis();  
10.            log.info(sm.getString("hostConfig.deployDescriptor",  
11.                     contextXml.getAbsolutePath()));  
12.         }  
13.   
14.         Context context = null;  
15.         boolean isExternalWar = false;  
16.         boolean isExternal = false;  
17.         File expandedDocBase = null;  
18.         FileInputStream fis = null;  
19.         try {  
20.             fis = new FileInputStream(contextXml);  
21.             synchronized (digesterLock) {  
22.                 try {  
23.                     context = (Context) digester.parse(fis);  
24.                 } catch (Exception e) {  
25.                     log.error(sm.getString(  
26.                             "hostConfig.deployDescriptor.error",  
27.                             contextXml.getAbsolutePath()), e);  
28.                     context = new FailedContext();  
29.                 } finally {  
30.                     digester.reset();  
31.                 }  
32.             }  
33.   
34.             Class<?> clazz = Class.forName(host.getConfigClass());  
35.             LifecycleListener listener =  
36.                 (LifecycleListener) clazz.newInstance();  
37.             context.addLifecycleListener(listener);  
38.   
39.             context.setConfigFile(contextXml.toURI().toURL());  
40.             context.setName(cn.getName());  
41.             context.setPath(cn.getPath());  
42.             context.setWebappVersion(cn.getVersion());  
43.             // Add the associated docBase to the redeployed list if it's a WAR  
44.             if (context.getDocBase() != null) {  
45.                 File docBase = new File(context.getDocBase());  
46.                 if (!docBase.isAbsolute()) {  
47.                     docBase = new File(appBase(), context.getDocBase());  
48.                 }  
49.                 // If external docBase, register .xml as redeploy first  
50.                 if (!docBase.getCanonicalPath().startsWith(  
51.                         appBase().getAbsolutePath() + File.separator)) {  
52.                     isExternal = true;  
53.                     deployedApp.redeployResources.put(  
54.                             contextXml.getAbsolutePath(),  
55.                             Long.valueOf(contextXml.lastModified()));  
56.                     deployedApp.redeployResources.put(docBase.getAbsolutePath(),  
57.                             Long.valueOf(docBase.lastModified()));  
58.                     if (docBase.getAbsolutePath().toLowerCase(Locale.ENGLISH).endsWith(".war")) {  
59.                         isExternalWar = true;  
60.                     }  
61.                 } else {  
62.                     log.warn(sm.getString("hostConfig.deployDescriptor.localDocBaseSpecified",  
63.                              docBase));  
64.                     // Ignore specified docBase  
65.                     context.setDocBase(null);  
66.                 }  
67.             }  
68.   
69.             host.addChild(context);  
70.         } catch (Throwable t) {  
71.             ExceptionUtils.handleThrowable(t);  
72.             log.error(sm.getString("hostConfig.deployDescriptor.error",  
73.                                    contextXml.getAbsolutePath()), t);  
74.         } finally {  
75.             if (fis != null) {  
76.                 try {  
77.                     fis.close();  
78.                 } catch (IOException e) {  
79.                     // Ignore  
80.                 }  
81.             }  
82.             // Get paths for WAR and expanded WAR in appBase  
83.   
84.             // default to appBase dir + name  
85.             expandedDocBase = new File(appBase(), cn.getBaseName());  
86.             if (context.getDocBase() != null  
87.                     && !context.getDocBase().toLowerCase(Locale.ENGLISH).endsWith(".war")) {  
88.                 // first assume docBase is absolute  
89.                 expandedDocBase = new File(context.getDocBase());  
90.                 if (!expandedDocBase.isAbsolute()) {  
91.                     // if docBase specified and relative, it must be relative to appBase  
92.                     expandedDocBase = new File(appBase(), context.getDocBase());  
93.                 }  
94.             }  
95.   
96.             boolean unpackWAR = unpackWARs;  
97.             if (unpackWAR && context instanceof StandardContext) {  
98.                 unpackWAR = ((StandardContext) context).getUnpackWAR();  
99.             }  
100.   
101.             // Add the eventual unpacked WAR and all the resources which will be  
102.             // watched inside it  
103.             if (isExternalWar) {  
104.                 if (unpackWAR) {  
105.                     deployedApp.redeployResources.put(expandedDocBase.getAbsolutePath(),  
106.                             Long.valueOf(expandedDocBase.lastModified()));  
107.                     addWatchedResources(deployedApp, expandedDocBase.getAbsolutePath(), context);  
108.                 } else {  
109.                     addWatchedResources(deployedApp, null, context);  
110.                 }  
111.             } else {  
112.                 // Find an existing matching war and expanded folder  
113.                 if (!isExternal) {  
114.                     File warDocBase = new File(expandedDocBase.getAbsolutePath() + ".war");  
115.                     if (warDocBase.exists()) {  
116.                         deployedApp.redeployResources.put(warDocBase.getAbsolutePath(),  
117.                                 Long.valueOf(warDocBase.lastModified()));  
118.                     } else {  
119.                         // Trigger a redeploy if a WAR is added  
120.                         deployedApp.redeployResources.put(  
121.                                 warDocBase.getAbsolutePath(),  
122.                                 Long.valueOf(0));  
123.                     }  
124.                 }  
125.                 if (unpackWAR) {  
126.                     deployedApp.redeployResources.put(expandedDocBase.getAbsolutePath(),  
127.                             Long.valueOf(expandedDocBase.lastModified()));  
128.                     addWatchedResources(deployedApp,  
129.                             expandedDocBase.getAbsolutePath(), context);  
130.                 } else {  
131.                     addWatchedResources(deployedApp, null, context);  
132.                 }  
133.                 if (!isExternal) {  
134.                     // For external docBases, the context.xml will have been  
135.                     // added above.  
136.                     deployedApp.redeployResources.put(  
137.                             contextXml.getAbsolutePath(),  
138.                             Long.valueOf(contextXml.lastModified()));  
139.                 }  
140.             }  
141.             // Add the global redeploy resources (which are never deleted) at  
142.             // the end so they don't interfere with the deletion process  
143.             addGlobalRedeployResources(deployedApp);  
144.         }  
145.   
146.         if (host.findChild(context.getName()) != null) {  
147.             deployed.put(context.getName(), deployedApp);  
148.         }  
149.   
150.         if (log.isInfoEnabled()) {  
151.             log.info(sm.getString("hostConfig.deployDescriptor.finished",  
152.                 contextXml.getAbsolutePath(), Long.valueOf(System.currentTimeMillis() - startTime)));  
153.         }  
154.     }  

2.ContextConfig初始化时Override为否时时会依次加载conf/context.xml，HostConfig/Basecontext.xml.default，configFile配置文件。

Contextconfig.init代码

1. protected void init() {  
2.         // Called from StandardContext.init()  
3.   
4.         Digester contextDigester = createContextDigester();  
5.         contextDigester.getParser();  
6.   
7.         if (log.isDebugEnabled())  
8.             log.debug(sm.getString("contextConfig.init"));  
9.         context.setConfigured(false);  
10.         ok = true;  
11.   
12.         contextConfig(contextDigester);  
13.   
14.         createWebXmlDigester(context.getXmlNamespaceAware(), context.getXmlValidation());  
15.     }  

Contextconfig.contextconfig代码

1. protected void contextConfig(Digester digester) {  
2.   
3.         // Open the default context.xml file, if it exists  
4.         if (defaultContextXml == null && context instanceof StandardContext) {  
5.             defaultContextXml = ((StandardContext) context).getDefaultContextXml();  
6.         }  
7.         // set the default if we don't have any overrides  
8.         if (defaultContextXml == null)  
9.             getDefaultContextXml();  
10.   
11.         if (!context.getOverride()) {  
12.             File defaultContextFile = new File(defaultContextXml);  
13.             if (!defaultContextFile.isAbsolute()) {  
14.                 defaultContextFile = new File(getBaseDir(), defaultContextXml);  
15.             }  
16.             if (defaultContextFile.exists()) {  
17.                 try {  
18.                     URL defaultContextUrl = defaultContextFile.toURI().toURL();  
19.                     processContextConfig(digester, defaultContextUrl);  
20.                 } catch (MalformedURLException e) {  
21.                     log.error(sm.getString("contextConfig.badUrl", defaultContextFile), e);  
22.                 }  
23.             }  
24.   
25.             File hostContextFile = new File(getHostConfigBase(), Constants.HostContextXml);  
26.             if (hostContextFile.exists()) {  
27.                 try {  
28.                     URL hostContextUrl = hostContextFile.toURI().toURL();  
29.                     processContextConfig(digester, hostContextUrl);  
30.                 } catch (MalformedURLException e) {  
31.                     log.error(sm.getString("contextConfig.badUrl", hostContextFile), e);  
32.                 }  
33.             }  
34.         }  
35.         if (context.getConfigFile() != null)  
36.             processContextConfig(digester, context.getConfigFile());  
37.   
38.     }  

3.war包的解压

   context在start时会触发Lifecycle.BEFORE_START_EVENT，ContextConfig调用fixDocBase解压war包

  

Contextconfig.fixdocbase代码

1. protected void fixDocBase() throws IOException {  
2.   
3.         Host host = (Host) context.getParent();  
4.         String appBase = host.getAppBase();  
5.   
6.         File canonicalAppBase = new File(appBase);  
7.         if (canonicalAppBase.isAbsolute()) {  
8.             canonicalAppBase = canonicalAppBase.getCanonicalFile();  
9.         } else {  
10.             canonicalAppBase = new File(getBaseDir(), appBase).getCanonicalFile();  
11.         }  
12.   
13.         String docBase = context.getDocBase();  
14.         if (docBase == null) {  
15.             // Trying to guess the docBase according to the path  
16.             String path = context.getPath();  
17.             if (path == null) {  
18.                 return;  
19.             }  
20.             ContextName cn = new ContextName(path, context.getWebappVersion());  
21.             docBase = cn.getBaseName();  
22.         }  
23.   
24.         File file = new File(docBase);  
25.         if (!file.isAbsolute()) {  
26.             docBase = (new File(canonicalAppBase, docBase)).getPath();  
27.         } else {  
28.             docBase = file.getCanonicalPath();  
29.         }  
30.         file = new File(docBase);  
31.         String origDocBase = docBase;  
32.   
33.         ContextName cn = new ContextName(context.getPath(), context.getWebappVersion());  
34.         String pathName = cn.getBaseName();  
35.   
36.         boolean unpackWARs = true;  
37.         if (host instanceof StandardHost) {  
38.             unpackWARs = ((StandardHost) host).isUnpackWARs();  
39.             if (unpackWARs && context instanceof StandardContext) {  
40.                 unpackWARs = ((StandardContext) context).getUnpackWAR();  
41.             }  
42.         }  
43.   
44.         if (docBase.toLowerCase(Locale.ENGLISH).endsWith(".war") && !file.isDirectory()) {  
45.             URL war = UriUtil.buildJarUrl(new File(docBase));  
46.             if (unpackWARs) {  
47.                 docBase = ExpandWar.expand(host, war, pathName);  
48.                 file = new File(docBase);  
49.                 docBase = file.getCanonicalPath();  
50.                 if (context instanceof StandardContext) {  
51.                     ((StandardContext) context).setOriginalDocBase(origDocBase);  
52.                 }  
53.             } else {  
54.                 ExpandWar.validate(host, war, pathName);  
55.             }  
56.         } else {  
57.             File docDir = new File(docBase);  
58.             if (!docDir.exists()) {  
59.                 File warFile = new File(docBase + ".war");  
60.                 if (warFile.exists()) {  
61.                     URL war = UriUtil.buildJarUrl(warFile);  
62.                     if (unpackWARs) {  
63.                         docBase = ExpandWar.expand(host, war, pathName);  
64.                         file = new File(docBase);  
65.                         docBase = file.getCanonicalPath();  
66.                     } else {  
67.                         docBase = warFile.getCanonicalPath();  
68.                         ExpandWar.validate(host, war, pathName);  
69.                     }  
70.                 }  
71.                 if (context instanceof StandardContext) {  
72.                     ((StandardContext) context).setOriginalDocBase(origDocBase);  
73.                 }  
74.             }  
75.         }  
76.   
77.         if (docBase.startsWith(canonicalAppBase.getPath() + File.separatorChar)) {  
78.             docBase = docBase.substring(canonicalAppBase.getPath().length());  
79.             docBase = docBase.replace(File.separatorChar, '/');  
80.             if (docBase.startsWith("/")) {  
81.                 docBase = docBase.substring(1);  
82.             }  
83.         } else {  
84.             docBase = docBase.replace(File.separatorChar, '/');  
85.         }  
86.   
87.         context.setDocBase(docBase);  
88.   
89.     }