java ArrayList集合中的某个对象属性进行排序的实现代码
开发中有时候需要自己封装分页排序时,List如何对某一属性排序呢,分享一个小实例,大家共勉,希望能对大家有用,请多多指教。
1.Student的Bean如下:
public class Student { private int age; private String name; private String weight; public String getWeight() { return weight; } public void setWeight(String weight) { this.weight = weight; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } }
2.按照List中对象的Int类型属性进行排序
/** * 按照List中的某个Int类型的属性进行排序 * @param list */ @SuppressWarnings("unchecked") public static void sortIntMethod(List list){ Collections.sort(list, new Comparator(){ @Override public int compare(Object o1, Object o2) { Student stu1=(Student)o1; Student stu2=(Student)o2; if(stu1.getAge()>stu2.getAge()){ return 1; }else if(stu1.getAge()==stu2.getAge()){ return 0; }else{ return -1; } } }); System.out.println("/////////////排序之后///////////////"); for(int i=0;i<list.size();i++){ Student st=(Student)list.get(i); System.out.println("st.age="+st.getAge()+",st.name="+st.getName()); } }
3.按照List中对象的String类型的属性进行排序
1)方法一:
/** * 按照List中的某个String类型的属性进行排序 * @param list */ @SuppressWarnings("unchecked") public static void sortStringMethod(List list){ Collections.sort(list, new Comparator(){ @Override public int compare(Object o1, Object o2) { Student stu1=(Student)o1; Student stu2=(Student)o2; return stu1.getName().compareTo(stu2.getName()); } }); System.out.println("/////////////排序之后///////////////"); for(int i=0;i<list.size();i++){ Student st=(Student)list.get(i); System.out.println("st.age="+st.getAge()+",st.name="+st.getName()); } }
2)方法二:
使用java.text.RuleBasedCollator来实现,用来执行区分语言环境的String 比较:
/** * 按照List中的某个String类型的属性进行排序 * @param list */ @SuppressWarnings("unchecked") public static void sortByRuleBasedCollator(List list){ Collections.sort(list, new Comparator(){ @Override public int compare(Object o1, Object o2) { return ((java.text.RuleBasedCollator)java.text.Collator.getInstance(java.util.Locale.CHINA)).compare(((Student)o1).getName(), ((Student)o2).getName()); } }); System.out.println("/////////////排序之后///////////////"); for(int i=0;i<list.size();i++){ Student st=(Student)list.get(i); System.out.println("st.age="+st.getAge()+",st.name="+st.getName()); } }
4.测试排序的方法
@SuppressWarnings("unchecked") public static void main(String[] args) { ArrayList list=new ArrayList(); Student t1=new Student(); t1.setAge(35); t1.setName("wanglei"); list.add(t1); Student t2=new Student(); t2.setAge(4); t2.setName("lisi"); list.add(t2); Student t3=new Student(); t3.setAge(56); t3.setName("zhonghua"); list.add(t3); Student t4=new Student(); t4.setAge(39); t4.setName("waanglei"); list.add(t4); System.out.println("/////////////排序之前///////////////"); for(int i=0;i<list.size();i++){ Student st=(Student)list.get(i); System.out.println("st.age="+st.getAge()+",st.name="+st.getName()); } //按照List中的某个Int类型的属性进行排序 sortIntMethod(list); //按照List中的某个String类型的属性进行排序 sortStringMethod(list); }
5.结果
赞 (0)