冒泡排序法 根据实体中的某个字段对实体 进行排序
实体:
1 package com.kns.test; 2 3 import java.util.Date; 4 5 public class testClass { 6 private String name; 7 private Integer age; 8 private Date date; 9 10 public testClass(String name, Integer age, Date date) { 11 this.name = name; 12 this.age = age; 13 this.date = date; 14 } 15 16 public String getName() { 17 return name; 18 } 19 20 public void setName(String name) { 21 this.name = name; 22 } 23 24 public Integer getAge() { 25 return age; 26 } 27 28 public void setAge(Integer age) { 29 this.age = age; 30 } 31 32 public Date getDate() { 33 return date; 34 } 35 36 public void setDate(Date date) { 37 this.date = date; 38 } 39 }
排序:
1 package com.kns.test; 2 3 import java.util.ArrayList; 4 import java.util.Date; 5 import java.util.List; 6 7 public class demo3 { 8 9 public static void main(String[] args) { 10 testClass a = new testClass("shaojiajia",1, new Date()); 11 testClass b = new testClass("shaojiajia",17, new Date()); 12 testClass c = new testClass("shaojiajia",11, new Date()); 13 testClass d = new testClass("shaojiajia",19, new Date()); 14 testClass e = new testClass("shaojiajia",12, new Date()); 15 List<testClass> testClassList = new ArrayList<testClass>(); 16 testClassList.add(a); 17 testClassList.add(b); 18 testClassList.add(c); 19 testClassList.add(d); 20 testClassList.add(e); 21 testClassList.toArray(); 22 23 Object[] testClasses = testClassList.toArray(); 24 for (Object object : testClasses) { 25 testClass testClass = (testClass) object; 26 System.out.println(testClass.getAge()); 27 } 28 29 System.out.println("--------------------------------------"); 30 31 Object temp; 32 for (int i = 0; i < testClasses.length - 1; i++) { 33 for (int j = i+1; j < testClasses.length; j++) { 34 if (((testClass)testClasses[i]).getAge() < ((testClass)testClasses[j]).getAge()) { 35 temp = testClasses[j]; 36 testClasses[j] = testClasses[i]; 37 testClasses[i] = temp; 38 } 39 } 40 } 41 for (Object object : testClasses) { 42 testClass testClass = (testClass) object; 43 System.out.println(testClass.getAge()); 44 } 45 } 46 }
结果: