类基本方法（toString、hashCode、equals、compareTo）重写
使用jar包为 apache的commons集lang包1. toString() 【java bean类基本方法重写】实现一
public class Person {
String name;
int age;
boolean smoker;
...public String toString() {
return new ToStringBuilder(this).
append("name", name).
append("age", age).
append("smoker", smoker).
toString();
}
}实现二
public String toString() {
return ToStringBuilder.reflectionToString(this);
}2. hashCode()
public class Person {
String name;
int age;
boolean smoker;
...
public int hashCode() {
// you pick a hard-coded, randomly chosen, non-zero, odd number
// ideally different for each class
return new HashCodeBuilder(17, 37).
append(name).
append(age).
append(smoker).
toHashCode();
}
}3. equals(Object obj)
public boolean equals(Object obj) {
if (obj == null) { return false;
}
if (obj == this) { return true;
}
if (obj.getClass() != getClass()) {
return false;
}
MyClass rhs = (MyClass) obj;
return new EqualsBuilder()
.appendSuper(super.equals(obj))
.append(field1, rhs.field1)
.append(field2, rhs.field2)
.append(field3, rhs.field3)
.isEquals();
}4. compareTo(Object o)
public int compareTo(Object o) {
MyClass myClass = (MyClass) o;
return new CompareToBuilder()
.appendSuper(super.compareTo(o)
.append(this.field1, myClass.field1)
.append(this.field2, myClass.field2)
.append(this.field3, myClass.field3)
.toComparison();
}
