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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.Locale;
22 import java.util.Map;
23
24 import org.apache.logging.log4j.Logger;
25 import org.apache.logging.log4j.core.LogEvent;
26 import org.apache.logging.log4j.core.config.ConfigurationAware;
27 import org.apache.logging.log4j.core.config.plugins.util.PluginManager;
28 import org.apache.logging.log4j.core.config.plugins.util.PluginType;
29 import org.apache.logging.log4j.core.util.Loader;
30 import org.apache.logging.log4j.core.util.ReflectionUtil;
31 import org.apache.logging.log4j.status.StatusLogger;
32 import org.apache.logging.log4j.util.Constants;
33
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37 public class Interpolator extends AbstractConfigurationAwareLookup {
38
39 private static final String LOOKUP_KEY_WEB = "web";
40
41 private static final String LOOKUP_KEY_JNDI = "jndi";
42
43 private static final String LOOKUP_KEY_JVMRUNARGS = "jvmrunargs";
44
45 private static final Logger LOGGER = StatusLogger.getLogger();
46
47
48 private static final char PREFIX_SEPARATOR = ':';
49
50 private final Map<String, StrLookup> lookups = new HashMap<>();
51
52 private final StrLookup defaultLookup;
53
54 public Interpolator(final StrLookup defaultLookup) {
55 this(defaultLookup, null);
56 }
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64
65 public Interpolator(final StrLookup defaultLookup, final List<String> pluginPackages) {
66 this.defaultLookup = defaultLookup == null ? new MapLookup(new HashMap<String, String>()) : defaultLookup;
67 final PluginManager manager = new PluginManager(CATEGORY);
68 manager.collectPlugins(pluginPackages);
69 final Map<String, PluginType<?>> plugins = manager.getPlugins();
70
71 for (final Map.Entry<String, PluginType<?>> entry : plugins.entrySet()) {
72 try {
73 final Class<? extends StrLookup> clazz = entry.getValue().getPluginClass().asSubclass(StrLookup.class);
74 lookups.put(entry.getKey(), ReflectionUtil.instantiate(clazz));
75 } catch (final Throwable t) {
76 handleError(entry.getKey(), t);
77 }
78 }
79 }
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83
84 public Interpolator() {
85 this((Map<String, String>) null);
86 }
87
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90
91 public Interpolator(final Map<String, String> properties) {
92 this.defaultLookup = new MapLookup(properties == null ? new HashMap<String, String>() : properties);
93
94 lookups.put("log4j", new Log4jLookup());
95 lookups.put("sys", new SystemPropertiesLookup());
96 lookups.put("env", new EnvironmentLookup());
97 lookups.put("main", MainMapLookup.MAIN_SINGLETON);
98 lookups.put("marker", new MarkerLookup());
99 lookups.put("java", new JavaLookup());
100
101 try {
102
103 lookups.put(LOOKUP_KEY_JNDI,
104 Loader.newCheckedInstanceOf("org.apache.logging.log4j.core.lookup.JndiLookup", StrLookup.class));
105 } catch (final LinkageError | Exception e) {
106 handleError(LOOKUP_KEY_JNDI, e);
107 }
108
109 try {
110
111 lookups.put(LOOKUP_KEY_JVMRUNARGS,
112 Loader.newCheckedInstanceOf("org.apache.logging.log4j.core.lookup.JmxRuntimeInputArgumentsLookup",
113 StrLookup.class));
114 } catch (final LinkageError | Exception e) {
115 handleError(LOOKUP_KEY_JVMRUNARGS, e);
116 }
117 lookups.put("date", new DateLookup());
118 lookups.put("ctx", new ContextMapLookup());
119 if (Constants.IS_WEB_APP) {
120 try {
121 lookups.put(LOOKUP_KEY_WEB,
122 Loader.newCheckedInstanceOf("org.apache.logging.log4j.web.WebLookup", StrLookup.class));
123 } catch (final Exception ignored) {
124 handleError(LOOKUP_KEY_WEB, ignored);
125 }
126 } else {
127 LOGGER.debug("Not in a ServletContext environment, thus not loading WebLookup plugin.");
128 }
129 }
130
131 private void handleError(final String lookupKey, final Throwable t) {
132 switch (lookupKey) {
133 case LOOKUP_KEY_JNDI:
134
135 LOGGER.warn(
136 "JNDI lookup class is not available because this JRE does not support JNDI." +
137 " JNDI string lookups will not be available, continuing configuration. Ignoring " + t);
138 break;
139 case LOOKUP_KEY_JVMRUNARGS:
140
141 LOGGER.warn(
142 "JMX runtime input lookup class is not available because this JRE does not support JMX. " +
143 "JMX lookups will not be available, continuing configuration. Ignoring " + t);
144 break;
145 case LOOKUP_KEY_WEB:
146 LOGGER.info("Log4j appears to be running in a Servlet environment, but there's no log4j-web module " +
147 "available. If you want better web container support, please add the log4j-web JAR to your " +
148 "web archive or server lib directory.");
149 break;
150 default:
151 LOGGER.error("Unable to create Lookup for {}", lookupKey, t);
152 }
153 }
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168 @Override
169 public String lookup(final LogEvent event, String var) {
170 if (var == null) {
171 return null;
172 }
173
174 final int prefixPos = var.indexOf(PREFIX_SEPARATOR);
175 if (prefixPos >= 0) {
176 final String prefix = var.substring(0, prefixPos).toLowerCase(Locale.US);
177 final String name = var.substring(prefixPos + 1);
178 final StrLookup lookup = lookups.get(prefix);
179 if (lookup instanceof ConfigurationAware) {
180 ((ConfigurationAware) lookup).setConfiguration(configuration);
181 }
182 String value = null;
183 if (lookup != null) {
184 value = event == null ? lookup.lookup(name) : lookup.lookup(event, name);
185 }
186
187 if (value != null) {
188 return value;
189 }
190 var = var.substring(prefixPos + 1);
191 }
192 if (defaultLookup != null) {
193 return event == null ? defaultLookup.lookup(var) : defaultLookup.lookup(event, var);
194 }
195 return null;
196 }
197
198 @Override
199 public String toString() {
200 final StringBuilder sb = new StringBuilder();
201 for (final String name : lookups.keySet()) {
202 if (sb.length() == 0) {
203 sb.append('{');
204 } else {
205 sb.append(", ");
206 }
207
208 sb.append(name);
209 }
210 if (sb.length() > 0) {
211 sb.append('}');
212 }
213 return sb.toString();
214 }
215 }