list排序,根据list中存放对象的某一属性排序

    xiaoxiao2024-04-21  12

    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 1)按照List中对象的Int类型属性进行排序的结果:   2)按照按照List中对象的String类型的属性进行排序的结果:  

    转载请注明原文地址: https://ju.6miu.com/read-1288211.html
    最新回复(0)