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17 package org.apache.logging.log4j.core.lookup;
18
19 import java.util.HashMap;
20 import java.util.List;
21 import java.util.Map;
22
23 import org.apache.logging.log4j.Logger;
24 import org.apache.logging.log4j.core.LogEvent;
25 import org.apache.logging.log4j.core.config.ConfigurationAware;
26 import org.apache.logging.log4j.core.config.plugins.util.PluginManager;
27 import org.apache.logging.log4j.core.config.plugins.util.PluginType;
28 import org.apache.logging.log4j.core.util.Loader;
29 import org.apache.logging.log4j.core.util.ReflectionUtil;
30 import org.apache.logging.log4j.status.StatusLogger;
31
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34
35 public class Interpolator extends AbstractConfigurationAwareLookup {
36
37 private static final String LOOKUP_KEY_WEB = "web";
38
39 private static final String LOOKUP_KEY_JNDI = "jndi";
40
41 private static final String LOOKUP_KEY_JVMRUNARGS = "jvmrunargs";
42
43 private static final Logger LOGGER = StatusLogger.getLogger();
44
45
46 private static final char PREFIX_SEPARATOR = ':';
47
48 private final Map<String, StrLookup> lookups = new HashMap<>();
49
50 private final StrLookup defaultLookup;
51
52 public Interpolator(final StrLookup defaultLookup) {
53 this(defaultLookup, null);
54 }
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63 public Interpolator(final StrLookup defaultLookup, final List<String> pluginPackages) {
64 this.defaultLookup = defaultLookup == null ? new MapLookup(new HashMap<String, String>()) : defaultLookup;
65 final PluginManager manager = new PluginManager(CATEGORY);
66 manager.collectPlugins(pluginPackages);
67 final Map<String, PluginType<?>> plugins = manager.getPlugins();
68
69 for (final Map.Entry<String, PluginType<?>> entry : plugins.entrySet()) {
70 try {
71 final Class<? extends StrLookup> clazz = entry.getValue().getPluginClass().asSubclass(StrLookup.class);
72 lookups.put(entry.getKey(), ReflectionUtil.instantiate(clazz));
73 } catch (final Throwable t) {
74 handleError(entry.getKey(), t);
75 }
76 }
77 }
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81
82 public Interpolator() {
83 this((Map<String, String>) null);
84 }
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87
88
89 public Interpolator(final Map<String, String> properties) {
90 this.defaultLookup = new MapLookup(properties == null ? new HashMap<String, String>() : properties);
91
92 lookups.put("log4j", new Log4jLookup());
93 lookups.put("sys", new SystemPropertiesLookup());
94 lookups.put("env", new EnvironmentLookup());
95 lookups.put("main", MainMapLookup.MAIN_SINGLETON);
96 lookups.put("marker", new MarkerLookup());
97 lookups.put("java", new JavaLookup());
98
99 try {
100
101 lookups.put(LOOKUP_KEY_JNDI,
102 Loader.newCheckedInstanceOf("org.apache.logging.log4j.core.lookup.JndiLookup", StrLookup.class));
103 } catch (final LinkageError | Exception e) {
104 handleError(LOOKUP_KEY_JNDI, e);
105 }
106
107 try {
108
109 lookups.put(LOOKUP_KEY_JVMRUNARGS,
110 Loader.newCheckedInstanceOf("org.apache.logging.log4j.core.lookup.JmxRuntimeInputArgumentsLookup",
111 StrLookup.class));
112 } catch (final LinkageError | Exception e) {
113 handleError(LOOKUP_KEY_JVMRUNARGS, e);
114 }
115 lookups.put("date", new DateLookup());
116 lookups.put("ctx", new ContextMapLookup());
117 if (Loader.isClassAvailable("javax.servlet.ServletContext")) {
118 try {
119 lookups.put(LOOKUP_KEY_WEB,
120 Loader.newCheckedInstanceOf("org.apache.logging.log4j.web.WebLookup", StrLookup.class));
121 } catch (final Exception ignored) {
122 handleError(LOOKUP_KEY_WEB, ignored);
123 }
124 } else {
125 LOGGER.debug("Not in a ServletContext environment, thus not loading WebLookup plugin.");
126 }
127 }
128
129 private void handleError(final String lookupKey, final Throwable t) {
130 switch (lookupKey) {
131 case LOOKUP_KEY_JNDI:
132
133 LOGGER.warn(
134 "JNDI lookup class is not available because this JRE does not support JNDI." +
135 " JNDI string lookups will not be available, continuing configuration. Ignoring " + t);
136 break;
137 case LOOKUP_KEY_JVMRUNARGS:
138
139 LOGGER.warn(
140 "JMX runtime input lookup class is not available because this JRE does not support JMX. " +
141 "JMX lookups will not be available, continuing configuration. Ignoring " + t);
142 break;
143 case LOOKUP_KEY_WEB:
144 LOGGER.info("Log4j appears to be running in a Servlet environment, but there's no log4j-web module " +
145 "available. If you want better web container support, please add the log4j-web JAR to your " +
146 "web archive or server lib directory.");
147 break;
148 default:
149 LOGGER.error("Unable to create Lookup for {}", lookupKey, t);
150 }
151 }
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166 @Override
167 public String lookup(final LogEvent event, String var) {
168 if (var == null) {
169 return null;
170 }
171
172 final int prefixPos = var.indexOf(PREFIX_SEPARATOR);
173 if (prefixPos >= 0) {
174 final String prefix = var.substring(0, prefixPos);
175 final String name = var.substring(prefixPos + 1);
176 final StrLookup lookup = lookups.get(prefix);
177 if (lookup instanceof ConfigurationAware) {
178 ((ConfigurationAware) lookup).setConfiguration(configuration);
179 }
180 String value = null;
181 if (lookup != null) {
182 value = event == null ? lookup.lookup(name) : lookup.lookup(event, name);
183 }
184
185 if (value != null) {
186 return value;
187 }
188 var = var.substring(prefixPos + 1);
189 }
190 if (defaultLookup != null) {
191 return event == null ? defaultLookup.lookup(var) : defaultLookup.lookup(event, var);
192 }
193 return null;
194 }
195
196 @Override
197 public String toString() {
198 final StringBuilder sb = new StringBuilder();
199 for (final String name : lookups.keySet()) {
200 if (sb.length() == 0) {
201 sb.append('{');
202 } else {
203 sb.append(", ");
204 }
205
206 sb.append(name);
207 }
208 if (sb.length() > 0) {
209 sb.append('}');
210 }
211 return sb.toString();
212 }
213 }