java接口返回参数按照请求参数进行排序方式
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java接口返回参数按照请求参数进行排序
在项目实际开发中可能遇到过这种问题，接口请求参数顺序是[a,b,c]，结果返回的数据是[bObject，cObject，aObject]，导致这种原因可能是底层采用了设计模式，或者是表拼接查询，本文主要就是为了实现这种功能，采用流的方法
代码实现
import lombok.Data;
import java.io.Serializable;
@Data
public class SkuInfo implements Serializable {
private static final long serialVersionUID = -6242151519713186291L;
private String spuId;
private String skuId;
private String productName;
private String picture;
private String link;
}
排序
import com.alibaba.fastjson.JSON;
import com.google.common.collect.Lists;
import com.wanli.databoard.dto.SkuInfo;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;
public class SkuSortTest {
public static void main(String[] args) {
List<String> skuIdList = Arrays.asList("sku1", "sku2", "sku3", "sku4");
//用于模拟接口入参
System.out.println("skuid列表：" + JSON.toJSONString(skuIdList));
System.out.println();
List<SkuInfo> skuInfoList = Lists.newArrayList();
SkuInfo s1 = new SkuInfo();
s1.setSpuId("spu1");
s1.setSkuId("sku1");
s1.setProductName("商品1");
s1.setPicture("p1");
s1.setLink("link1");
skuInfoList.add(s1);
SkuInfo s4 = new SkuInfo();
s4.setSpuId("spu1");
s4.setSkuId("sku4");
s4.setProductName("商品2");
s4.setPicture("p4");
s4.setLink("link4");
skuInfoList.add(s4);
SkuInfo s3 = new SkuInfo();
s3.setSpuId("spu2");
s3.setSkuId("sku3");
s3.setProductName("商品3");
s3.setPicture("p3");
s3.setLink("link3");
skuInfoList.add(s3);
SkuInfo s2 = new SkuInfo();
s2.setSpuId("spu2");
s2.setSkuId("sku2");
s2.setProductName("商品2");
s2.setPicture("p2");
s2.setLink("link2");
skuInfoList.add(s2);
//用于模拟接口入参
System.out.println("skuInfoList列表：" + JSON.toJSONString(skuInfoList));
System.out.println();
//按照请求参数进行排序
List<SkuInfo> resultList = skuInfoList.stream().sorted(getSkuIdListComparator(skuIdList)).collect(Collectors.toList());
System.out.println("排序完成后的结果：" + JSON.toJSONString(resultList));
}
private static Comparator<SkuInfo> getSkuIdListComparator(List<String> skuIds) {
return (o1, o2) -> {
int order1 = 0, order2 = 0;
for (int i = 0; i < skuIds.size(); i++) {
if (Objects.equals(o1.getSkuId(), skuIds.get(i))) {
order1 = i;
}
if (Objects.equals(o2.getSkuId(), skuIds.get(i))) {
order2 = i;
}
}
return order1 - order2;
};
}
}
代码运行结果：
skuid列表：["sku1","sku2","sku3","sku4"]
skuInfoList列表：[{"link":"link1","picture":"p1","productName":"商品1","skuId":"sku1","spuId":"spu1"},{"link":"link4","picture":"p4","productName":"商品2","skuId":"sku4","spuId":"spu1"},{"link":"link3","picture":"p3","productName":"商品3","skuId":"sku3","spuId":"spu2"},{"link":"link2","picture":"p2","productName":"商品2","skuId":"sku2","spuId":"spu2"}]
排序完成后的结果：[{"link":"link1","picture":"p1","productName":"商品1","skuId":"sku1","spuId":"spu1"},{"link":"link2","picture":"p2","productName":"商品2","skuId":"sku2","spuId":"spu2"},{"link":"link3","picture":"p3","productName":"商品3","skuId":"sku3","spuId":"spu2"},{"link":"link4","picture":"p4","productName":"商品2","skuId":"sku4","spuId":"spu1"}]
java通过接口进行排序
描述
对学生排序，先按成绩由大到小排序，成绩相同按姓名字母排序，姓名相同再按学号由小到大排序。
package class="lazy" data-src7;
import java.util.*;
class Student implements Comparable<Student> {
private String name;
private int id;
private int grade;
public Student(String name, int id, int grade) {
this.name = name;
this.id = id;
this.grade = grade;
}
public int compareTo(Student o) {
Student s = (Student) o;
if (this.grade>s.grade) {
return -1;//返回负数,当前成绩排前
} else if (this.grade == s.grade) {
// if (this.name.hashCode() < s.name.hashCode()) {
// return -1; //使用hashCode()
if (this.name.compareTo(s.name)<0) {
return -1; //使用compareTo
// } else if (this.name.hashCode() == s.name.hashCode()) {
} else if (this.name.compareTo(s.name)==0) {
if (this.id < s.id) {
return -1;
} else if (this.id == s.id) {
return 0;//此处说明姓名学号成绩全部相同
} else {
return 1;
}
} else {
return 1;// 返回正数，当前对象排后
}
} else {
return 1;
}
}
@Override
public String toString() {
return "姓名：" + this.name +",学号："+this.id+ ",成绩：" + this.grade + "\n";
}
}
public class Test {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
Student[] arr = new Student[3];
for (int i = 0; i < arr.length; i++) {
System.out.println("输入第" + (i + 1) + "个学生的姓名、学号和成绩：");
String name = in.next();
int id = in.nextInt();
int grade = in.nextInt();
arr[i] = new Student(name, id, grade);
}
System.out.println("排序前：");
for(int i = 0; i < arr.length; i++){
System.out.println(arr[i]);
}
System.out.println("排序后：");{
List<Student>students=Arrays.asList(arr);
Collections.sort(students);
System.out.println(students);
//也可以使用冒泡排序
for(int i=0;i<arr.length;i++) {
System.out.println(arr[i]);
}
}
}
}
知识点
1.Comparable接口
包含的比较方法：
public interface Comparable< T >{
public int compareTo(T obj);
}比较当前对象与外来对象，让当前对象排前就返回负值，反之返回正值，相等返回0
关于Comparable接口的简单举例：对人的姓和名进行排序
package class="lazy" data-src7;
import java.util.*;
class Person implements Comparable<Person>{
private final String lastname,firstname;//lastname表示姓 firstname表示名
public Person(String lastname,String firstname){
this.lastname=lastname;
this.firstname=firstname;
}
public String lastname(){
return lastname;
}
public String firstname(){
return firstname;
}
public boolean equals(Object obj){
Person n=(Person)obj;
return (n.lastname.equals(lastname)&&n.firstname.equals(firstname));
}
public int hashCode(){
return lastname.hashCode()+firstname.hashCode();
}
public String toString(){
return lastname+" "+firstname;
}
public int compareTo(Person n){
if(lastname.compareTo(n.lastname)<0)
return -1;
if(lastname.compareTo(n.lastname)>0)
return 1;
else {
if(firstname.compareTo(n.firstname)<0)
return -1;
if(firstname.compareTo(n.firstname)>0)
return 1;
else return 0;
}
}
}
public class Test {
public static void main(String[]args){
Person personArr[]={
new Person("Zhang","Liang"),
new Person("Li","Si"),
new Person("Wang","Ning"),
new Person("Zhang","San"),
new Person("Chen","Yi")
};
List<Person>persons=Arrays.asList(personArr);
Collections.sort(persons);
System.out.println(persons);
}
}
运行结果：
2.Comparator接口
包含的比较方法：
public interface Comparator< T >{
public int compare(T obj1,T obj2);
}比较对象obj1和obj2，让obj1位于obj2之前则返回负值
简单举例：对姓名排序
package class="lazy" data-src7;
import sun.awt.geom.AreaOp;
import java.util.*;
class Person{
private String name;
public Person(String name){
this.name=name;
}
public String getName(){
return name;
}
public String toString(){
return name;
}
}
public class Test{
static final Comparator<Person> ODER_BY_NAME=new Comparator<Person>() {
@Override
public int compare(Person o1, Person o2) {
return o1.getName().compareTo(o2.getName());
}
};
public static void main(String[] args) {
Person personArr[]={
new Person("ZhangLiang"),
new Person("LiSi"),
new Person("WangNing"),
new Person("ZhangSan"),
new Person("ChenYi")
};
List<Person>persons=Arrays.asList(personArr);
Collections.sort(persons,ODER_BY_NAME);
System.out.println(persons);
}
}
运行结果：
以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程网。
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