第一種方法,就是list中對象實現Comparable接口,代碼如下:
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public class Person implements Comparable<Person> {
private String name;
private Integer order;
/**
* @return the name
*/
public String getName() {
return name;
}
/**
* @param name
* the name to set
*/
public void setName(String name) {
this .name = name;
}
/**
* @return the order
*/
public Integer getOrder() {
return order;
}
/**
* @param order
* the order to set
*/
public void setOrder(Integer order) {
this .order = order;
}
@Override
public int compareTo(Person arg0) {
return this .getOrder().compareTo(arg0.getOrder());
}
} |
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public static void main(String[] args) {
List<Person> listA = new ArrayList<Person>();
Person p1 = new Person();
Person p2 = new Person();
Person p3 = new Person();
p1.setName( "name1" );
p1.setOrder( 1 );
p2.setName( "name2" );
p2.setOrder( 2 );
p3.setName( "name3" );
p3.setOrder( 3 );
listA.add(p2);
listA.add(p1);
listA.add(p3);
Collections.sort(listA);
for (Person p : listA) {
System.out.println(p.getName());
}
} |
第二種方法,就是在重載Collections.sort方法,代碼如下:
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public class Person {
private String name;
private Integer order;
/**
* @return the name
*/
public String getName() {
return name;
}
/**
* @param name
* the name to set
*/
public void setName(String name) {
this .name = name;
}
/**
* @return the order
*/
public Integer getOrder() {
return order;
}
/**
* @param order
* the order to set
*/
public void setOrder(Integer order) {
this .order = order;
}
} |
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public static void main(String[] args) {
List<Person> listA = new ArrayList<Person>();
Person p1 = new Person();
Person p2 = new Person();
Person p3 = new Person();
p1.setName( "name1" );
p1.setOrder( 1 );
p2.setName( "name2" );
p2.setOrder( 2 );
p3.setName( "name3" );
p3.setOrder( 3 );
listA.add(p2);
listA.add(p1);
listA.add(p3);
Collections.sort(listA, new Comparator<Person>() {
public int compare(Person arg0, Person arg1) {
return arg0.getOrder().compareTo(arg1.getOrder());
}
});
for (Person p : listA) {
System.out.println(p.getName());
}
}
|
兩次執行的結果都是:
name1
name2
name3