2009/04/15 - Apache HiveMind has been retired.

For more information, please explore the Attic.

Clover coverage report - Code Coverage for hivemind release 1.2.1
Coverage timestamp: Fri Feb 10 2006 16:33:43 PST
file stats: LOC: 280   Methods: 14
NCLOC: 152   Classes: 1
 
 Source file Conditionals Statements Methods TOTAL
MethodSignature.java 98% 98.8% 100% 98.6%
coverage coverage
 1    // Copyright 2004, 2005 The Apache Software Foundation
 2    //
 3    // Licensed under the Apache License, Version 2.0 (the "License");
 4    // you may not use this file except in compliance with the License.
 5    // You may obtain a copy of the License at
 6    //
 7    // http://www.apache.org/licenses/LICENSE-2.0
 8    //
 9    // Unless required by applicable law or agreed to in writing, software
 10    // distributed under the License is distributed on an "AS IS" BASIS,
 11    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 12    // See the License for the specific language governing permissions and
 13    // limitations under the License.
 14   
 15    package org.apache.hivemind.service;
 16   
 17    import java.lang.reflect.Method;
 18   
 19    /**
 20    * A representation of a {@link java.lang.reflect.Method}, identifying the name, return type,
 21    * parameter types and exception types. Actual Method objects are tied to a particular class, and
 22    * don't compare well with other otherwise identical Methods from other classes or interface;
 23    * MethodSignatures are distinct from classes and compare well.
 24    * <p>
 25    * Because the intended purpose is to compare methods from interfaces (which are always public and
 26    * abstract) we don't bother to actually track the modifiers. In addition, at this time,
 27    * MethodSignature <em>does not distinguish between instance and static
 28    * methods</em>.
 29    *
 30    * @author Howard Lewis Ship
 31    */
 32    public class MethodSignature
 33    {
 34    private int _hashCode = -1;
 35   
 36    private Class _returnType;
 37   
 38    private String _name;
 39   
 40    private Class[] _parameterTypes;
 41   
 42    private Class[] _exceptionTypes;
 43   
 44  10799 public MethodSignature(Class returnType, String name, Class[] parameterTypes,
 45    Class[] exceptionTypes)
 46    {
 47  10799 _returnType = returnType;
 48  10799 _name = name;
 49  10799 _parameterTypes = parameterTypes;
 50  10799 _exceptionTypes = exceptionTypes;
 51    }
 52   
 53  2566 public MethodSignature(Method m)
 54    {
 55  2566 this(m.getReturnType(), m.getName(), m.getParameterTypes(), m.getExceptionTypes());
 56    }
 57   
 58    /**
 59    * Returns the exceptions for this method. Caution: do not modify the returned array. May return
 60    * null.
 61    */
 62  10680 public Class[] getExceptionTypes()
 63    {
 64  10680 return _exceptionTypes;
 65    }
 66   
 67  13147 public String getName()
 68    {
 69  13147 return _name;
 70    }
 71   
 72    /**
 73    * Returns the parameter types for this method. May return null. Caution: do not modify the
 74    * returned array.
 75    */
 76  10694 public Class[] getParameterTypes()
 77    {
 78  10694 return _parameterTypes;
 79    }
 80   
 81  10689 public Class getReturnType()
 82    {
 83  10689 return _returnType;
 84    }
 85   
 86  23813 public int hashCode()
 87    {
 88  23813 if (_hashCode == -1)
 89    {
 90   
 91  10693 _hashCode = _returnType.hashCode();
 92   
 93  10693 _hashCode = 31 * _hashCode + _name.hashCode();
 94   
 95  10693 int count = count(_parameterTypes);
 96   
 97  10693 for (int i = 0; i < count; i++)
 98  7377 _hashCode = 31 * _hashCode + _parameterTypes[i].hashCode();
 99   
 100  10693 count = count(_exceptionTypes);
 101   
 102  10693 for (int i = 0; i < count; i++)
 103  22 _hashCode = 31 * _hashCode + _exceptionTypes[i].hashCode();
 104    }
 105   
 106  23813 return _hashCode;
 107    }
 108   
 109  30451 private static int count(Object[] array)
 110    {
 111  30451 return array == null ? 0 : array.length;
 112    }
 113   
 114    /**
 115    * Returns true if the other object is an instance of MethodSignature with identical values for
 116    * return type, name, parameter types and exception types.
 117    */
 118  41 public boolean equals(Object o)
 119    {
 120  41 if (o == null || !(o instanceof MethodSignature))
 121  2 return false;
 122   
 123  39 MethodSignature ms = (MethodSignature) o;
 124   
 125  39 if (_returnType != ms._returnType)
 126  0 return false;
 127   
 128  39 if (!_name.equals(ms._name))
 129  1 return false;
 130   
 131  38 if (mismatch(_parameterTypes, ms._parameterTypes))
 132  1 return false;
 133   
 134  37 return !mismatch(_exceptionTypes, ms._exceptionTypes);
 135    }
 136   
 137  84 private boolean mismatch(Class[] a1, Class[] a2)
 138    {
 139  84 int a1Count = count(a1);
 140  84 int a2Count = count(a2);
 141   
 142  84 if (a1Count != a2Count)
 143  1 return true;
 144   
 145    // Hm. What if order is important (for exceptions)? We're really saying here that they
 146    // were derived from the name Method.
 147   
 148  83 for (int i = 0; i < a1Count; i++)
 149    {
 150  4 if (a1[i] != a2[i])
 151  1 return true;
 152    }
 153   
 154  82 return false;
 155    }
 156   
 157  15 public String toString()
 158    {
 159  15 StringBuffer buffer = new StringBuffer();
 160   
 161  15 buffer.append(ClassFabUtils.getJavaClassName(_returnType));
 162  15 buffer.append(" ");
 163  15 buffer.append(_name);
 164  15 buffer.append("(");
 165   
 166  15 for (int i = 0; i < count(_parameterTypes); i++)
 167    {
 168  4 if (i > 0)
 169  3 buffer.append(", ");
 170   
 171  4 buffer.append(ClassFabUtils.getJavaClassName(_parameterTypes[i]));
 172    }
 173   
 174  15 buffer.append(")");
 175   
 176  15 for (int i = 0; i < count(_exceptionTypes); i++)
 177    {
 178  2 if (i == 0)
 179  1 buffer.append(" throws ");
 180    else
 181  1 buffer.append(", ");
 182   
 183  2 buffer.append(_exceptionTypes[i].getName());
 184    }
 185   
 186  15 return buffer.toString();
 187    }
 188   
 189    /**
 190    * Returns a string consisting of the name of the method and its parameter values. This is
 191    * similar to {@link #toString()}, but omits the return type and information about thrown
 192    * exceptions. A unique id is used by {@link MethodIterator} to identify overlapping methods
 193    * (methods with the same name but different thrown exceptions).
 194    *
 195    * @since 1.1
 196    */
 197  2472 public String getUniqueId()
 198    {
 199  2472 StringBuffer buffer = new StringBuffer(_name);
 200  2472 buffer.append("(");
 201   
 202  2472 for (int i = 0; i < count(_parameterTypes); i++)
 203    {
 204  6373 if (i > 0)
 205  4445 buffer.append(",");
 206   
 207  6373 buffer.append(ClassFabUtils.getJavaClassName(_parameterTypes[i]));
 208    }
 209   
 210  2472 buffer.append(")");
 211   
 212  2472 return buffer.toString();
 213    }
 214   
 215    /**
 216    * Returns true if this signature has the same return type, name and parameters types as the
 217    * method signature passed in, and this signatures exceptions "trump" (are the same as, or
 218    * super-implementations of, all exceptions thrown by the other method signature).
 219    *
 220    * @since 1.1
 221    */
 222   
 223  11 public boolean isOverridingSignatureOf(MethodSignature ms)
 224    {
 225  11 if (_returnType != ms._returnType)
 226  1 return false;
 227   
 228  10 if (!_name.equals(ms._name))
 229  1 return false;
 230   
 231  9 if (mismatch(_parameterTypes, ms._parameterTypes))
 232  1 return false;
 233   
 234  8 return exceptionsEncompass(ms._exceptionTypes);
 235    }
 236   
 237    /**
 238    * The nuts and bolts of checking that another method signature's exceptions are a subset of
 239    * this signature's.
 240    *
 241    * @since 1.1
 242    */
 243   
 244  8 private boolean exceptionsEncompass(Class[] otherExceptions)
 245    {
 246  8 int ourCount = count(_exceptionTypes);
 247  8 int otherCount = count(otherExceptions);
 248   
 249    // If we have no exceptions, then ours encompass theirs only if they
 250    // have no exceptions, either.
 251   
 252  8 if (ourCount == 0)
 253  2 return otherCount == 0;
 254   
 255  6 boolean[] matched = new boolean[otherCount];
 256  6 int unmatched = otherCount;
 257   
 258  6 for (int i = 0; i < ourCount && unmatched > 0; i++)
 259    {
 260  6 for (int j = 0; j < otherCount; j++)
 261    {
 262    // Ignore exceptions that have already been matched
 263   
 264  10 if (matched[j])
 265  2 continue;
 266   
 267    // When one of our exceptions is a super-class of one of their exceptions,
 268    // then their exceptions is matched.
 269   
 270  8 if (_exceptionTypes[i].isAssignableFrom(otherExceptions[j]))
 271    {
 272  3 matched[j] = true;
 273  3 unmatched--;
 274    }
 275    }
 276    }
 277   
 278  6 return unmatched == 0;
 279    }
 280    }