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Don't use instanceOf to check equality #2

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e4efca6
Update version to 1.1.11.f1
Nov 22, 2012
d4f139e
Fix using instanceOf on equals generation.
Nov 22, 2012
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2 changes: 1 addition & 1 deletion org.jiayun.commons4e/META-INF/MANIFEST.MF
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
Manifest-Version: 1.0
Bundle-Name: Commons4E
Bundle-SymbolicName: org.jiayun.commons4e; singleton=true
Bundle-Version: 1.1.11
Bundle-Version: 1.1.11.f1
Bundle-ClassPath: commons4e.jar
Bundle-Activator: org.jiayun.commons4e.Commons4ePlugin
Bundle-Vendor: JiaYun
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37 changes: 30 additions & 7 deletions ....commons4e/src/org/jiayun/commons4e/internal/lang/generators/EqualsHashCodeGenerator.java
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Expand Up @@ -176,16 +176,39 @@ private String createEqualsMethod(final IType objectClass,
content.append("@Override\n");
}
content.append("public boolean equals(final Object other) {\n");
content.append("if (other == null) return false;\n");
if (compareReferences) {
content.append("if (this == other) return true;");
}
content.append("if ( !(other instanceof ");
content.append(objectClass.getElementName());
content.append(") ) return false;\n");
content.append(objectClass.getElementName());
content.append(" castOther = (");
content.append(objectClass.getElementName());
content.append(") other;\n");
// by definition a.equals(b) == b.equals(a) (symmetric), using instanceOf can't assure this
// example:
// class A {
// int field1;
// public A(int x) { field1 = x };
// }
// class B extends A {
// int field2;
// public A(int x, int y) { super(x); field2 = y };
// }
// ...
// A a = new A(1)
// B b = new B(1, 2);
// a.equals(b); // true
// b.equals(a); // false
//
// from jdk javadoc for equals:
// (equals) It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.

// content.append("if ( !(other instanceof ");
// content.append(objectClass.getElementName());
// content.append(") ) return false;\n");
content.append("if (!(other.getClass() == this.getClass())) return false;\n");

content.append(objectClass.getElementName());
content.append(" castOther = (");
content.append(objectClass.getElementName());
content.append(") other;\n");

content.append("return new EqualsBuilder()");
if (appendSuper) {
content.append(".appendSuper(super.equals(other))");
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