java接口返回参数按照请求参数进行排序方式

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;

/**

* @description 模拟接口结果类

* @author: WilsonMeng

* @create: 2021-01-26 14:26

**/

@Data

public class SkuInfo implements Serializable {

private static final long serialVersionUID = -6242151519713186291L;

/**

* spuId

*/

private String spuId;

/**

* skuId

*/

private String skuId;

/**

* 商品名称

*/

private String productName;

/**

* 商品图片

*/

private String picture;

/**

* 商品链接

*/

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;

/**

* @description

* @author: WilsonMeng

* @create: 2021-01-26 14:28

**/

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 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 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:

在这里插入图片描述

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 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:

在这里插入图片描述

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。

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