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gdata/java/sample/util/SimpleCommandLineParser.java

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+/* Copyright (c) 2008 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+package sample.util;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * A simple class that provides utilities to ease command line parsing.
+ *
+ * 
+ */
+public class SimpleCommandLineParser {
+
+  private Map<String,String> argMap;
+
+  /**
+   * Initializes the command line parser by parsing the command line
+   * args using simple rules.
+   * <p>
+   * The arguments are parsed into keys and values and are saved into
+   * a HashMap.  Any argument that begins with a '--' or '-' is assumed
+   * to be a key.  If the following argument doesn't have a '--'/'-' it
+   * is assumed to be a value of the preceding argument.
+   */
+  public SimpleCommandLineParser(String[] arg) {
+    argMap = new HashMap<String,String>();
+    for (int i = 0; i < arg.length ; i++) {
+      String key;
+      if (arg[i].startsWith("--")) {
+        key = arg[i].substring(2);
+      } else if(arg[i].startsWith("-")) {
+        key = arg[i].substring(1);
+      } else {
+        argMap.put(arg[i], null);
+        continue;
+      }
+      String value;
+      int index = key.indexOf('=');
+      if (index == -1) {
+        if (((i+1) < arg.length) &&
+            (arg[i+1].charAt(0) != '-')) {
+          argMap.put(key, arg[i+1]);
+          i++;
+        } else {
+          argMap.put(key, null);
+        }
+      } else {
+        value = key.substring(index+1);
+        key = key.substring(0, index);
+        argMap.put(key, value);
+      }
+    }
+  }
+
+  /**
+   * Returns the value of the first key found in the map.
+   */
+  public String getValue(String ... keys) {
+    for(int key_i = 0; key_i < keys.length; key_i++) {
+      if(argMap.get(keys[key_i]) != null) {
+        return argMap.get(keys[key_i]);
+      }
+    }
+    return null;
+  }
+
+  /**
+   * Returns true if any of the given keys are present in the map.
+   */
+  public boolean containsKey(String ... keys) {
+    Set<String> keySet = argMap.keySet();
+    for (Iterator<String> keysIter = keySet.iterator(); keysIter.hasNext();) {
+      String key = keysIter.next();
+      for (int key_i = 0; key_i < keys.length; key_i++) {
+        if (key.equals(keys[key_i])) {
+          return true;
+        }
+      }
+    }
+    return false;
+  }
+}