如何使用Java从JSONArray中删除重复对象并对其进行排序
我的JSON是：如何使用Java从JSONArray中删除重复对象并对其进行排序,java,json,sorting,Java,Json,Sorting,我的JSON是： [ { "distance":32, "stationCode":"MIG", "name":"Midghat", "platforms":"2" }, { "distance":32, "stationCode":"MIG", "name":"Midghat", "platforms":"2" }, { "distance":69,
[
{
"distance":32,
"stationCode":"MIG",
"name":"Midghat",
"platforms":"2"
},
{
"distance":32,
"stationCode":"MIG",
"name":"Midghat",
"platforms":"2"
},
{
"distance":69,
"stationCode":"MDDP",
"name":"Mandideep",
"platforms":"2"
},
{
"distance":69,
"stationCode":"MDDP",
"name":"Mandideep",
"platforms":"2"
},
{
"distance":18,
"stationCode":"HBD",
"name":"Hoshangabad",
"platforms":"2"
},
{
"distance":18,
"stationCode":"HBD",
"name":"Hoshangabad",
"platforms":"2"
},
{
"distance":37,
"stationCode":"CHQ",
"name":"Choka",
"platforms":"2"
},
{
"distance":37,
"stationCode":"CHQ",
"name":"Choka",
"platforms":"2"
},
{
"distance":85,
"stationCode":"HBJ",
"name":"Habibganj",
"platforms":"5"
},
{
"distance":85,
"stationCode":"HBJ",
"name":"Habibganj",
"platforms":"5"
},
{
"distance":0,
"stationCode":"ET",
"name":"ItarsiJn",
"platforms":"28"
},
{
"distance":8,
"stationCode":"PRKD",
"name":"Powerkheda",
"platforms":"2"
},
{
"distance":8,
"stationCode":"PRKD",
"name":"Powerkheda",
"platforms":"2"
},
{
"distance":55,
"stationCode":"ODG",
"name":"ObaidullaGanj",
"platforms":"2"
},
{
"distance":55,
"stationCode":"ODG",
"name":"ObaidullaGanj",
"platforms":"2"
},
{
"distance":44,
"stationCode":"BKA",
"name":"Barkhera",
"platforms":"2"
},
{
"distance":44,
"stationCode":"BKA",
"name":"Barkhera",
"platforms":"2"
},
{
"distance":79,
"stationCode":"MSO",
"name":"Misrod",
"platforms":"2"
},
{
"distance":79,
"stationCode":"MSO",
"name":"Misrod",
"platforms":"2"
},
{
"distance":25,
"stationCode":"BNI",
"name":"Budni",
"platforms":"2"
},
{
"distance":25,
"stationCode":"BNI",
"name":"Budni",
"platforms":"2"
},
{
"distance":91,
"stationCode":"BPL",
"name":"BhopalJn",
"platforms":"6"
},
{
"distance":63,
"stationCode":"ITKL",
"name":"ItayaKalan",
"platforms":"2"
},
{
"distance":63,
"stationCode":"ITKL",
"name":"ItayaKalan",
"platforms":"2"
}
]
我希望它根据距离排序并删除重复的stationCode。我试着使用simple if else，但这个过程太多了。。有没有专门用于排序的快捷方式。没有直接的方法，但您可以按照下面提到的方法进行操作：
我不久前编写了这个实用程序，它对
JSONObjects的JSONArray
进行排序
唯一的条件是JSONobjects
必须包含要基于排序的键（如果要基于多个键排序，它还接受一组键）
以下是使用ArrayList..contains（）方法连接'2'JSONArray并从连接的JSONArray中删除重复项的代码：
导入java.util.ArrayList；
导入java.util.List；
导入org.json.JSONArray；
导入org.json.JSONException；
导入org.json.JSONObject；
/**
*@author RAM K K
*@gmailkkram523@gmail.com
*
*/
公共类JSONOperations{
公共静态void main（字符串[]args）{
字符串s3；
目前，除除“姓名”以外的其他一些学校名称：：，，，，，，，，，，，，，，，，，，，，“姓名”名称：：，，，，，，，，，，，，，，，，，，，，，，除除除除“名称”名称：：，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，，)；
字符串s2=“[{\'name\'：\'Mack\'，\'car\'：\'VW\'，{\'name\'：\'Steve\'，\'car\'：\'Mercedes-Benz\'，{\'name\'：'Bob\'，\'car\'：'Ford\'”；
试一试{
JSONArray sourceArray=新的JSONArray（s2）；
JSONArray destinationArray=新的JSONArray（s1）；
System.out.println（sourceArray）；
系统输出打印LN（目标阵列）；
对于（int i=0；i
发布您尝试过的代码和错误：）这样您可以更容易地学习，我们也可以帮助您！当然有一种直接的排序方法：）谢谢，它对排序起了作用。。过滤重复了我的另一个逻辑：）通过排序节省了很多时间：）@GovindMantri，酷伙计，只要你知道你可以用多个键对DEC进行排序。这不符合问题的要求。“我希望它能根据距离排序，并删除重复的stationCode。”此外，你还可以重复发布。请参阅主题行“如何使用Java从JSONArray中删除重复的对象并对其进行排序”，这不是网站的工作方式。题目只是一个介绍。此外，即使网站是这样工作的，它也只是强化了我的观点，因为你的代码没有显示如何对列表进行排序。是的，我的代码不是用来排序的，而是用来删除重复项的！
import java.util.Collections;
import java.util.Comparator;
import java.util.Random;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
public class JSONArraySort {
@SuppressWarnings("unchecked")
public static void sortASCE(JSONArray array, Object key) {
Object[] keys = { key };
Collections.sort(array, new JSONArrayComparator(false, keys));
}
@SuppressWarnings("unchecked")
public static void sortDESC(JSONArray array, Object key) {
Object[] keys = { key };
Collections.sort(array, new JSONArrayComparator(true, keys));
}
@SuppressWarnings("unchecked")
public static void sortASCE(JSONArray array, Object[] key) {
Collections.sort(array, new JSONArrayComparator(false, key));
}
@SuppressWarnings("unchecked")
public static void sortDESC(JSONArray array, Object[] key) {
Collections.sort(array, new JSONArrayComparator(true, key));
}
private static class JSONArrayComparator implements Comparator<JSONObject> {
private final Object[] KEYS;
private final boolean DESC;
public JSONArrayComparator(boolean DESC, Object[] KEYS) {
this.KEYS = KEYS;
this.DESC = DESC;
}
@Override
public int compare(JSONObject object1, JSONObject object2) {
int length = KEYS.length;
for(int i = 0 ; i < length ; i++){
String KEY = KEYS[i].toString();
Object one = object1.get(KEY);
Object two = object2.get(KEY);
if(Number.class.isAssignableFrom(one.getClass()) && Number.class.isAssignableFrom(two.getClass())){
Double numOne = Number.class.cast(one).doubleValue();
Double numTwo = Number.class.cast(two).doubleValue();
int compared = 0;
if(DESC){
compared = numTwo.compareTo(numOne);
}else{
compared = numOne.compareTo(numTwo);
}
if(i == KEYS.length - 1 || compared != 0){
return compared;
}
}else{
int compared = 0;
if(DESC){
compared = two.toString().compareTo(one.toString());
}else{
compared = one.toString().compareTo(two.toString());
}
if(i == KEYS.length - 1 || compared != 0){
return compared;
}
}
}
// this shouldn't happen.
return 0;
}
}
//testing...
public static void main(String... args) {
JSONArray array1 = new JSONArray();
for(int i = 0 ; i < 100 ; i++){
Random random = new Random();
int num1 = random.nextInt(10);
int num2 = random.nextInt(10);
JSONObject object = new JSONObject();
object.put("num1", num1);
object.put("num2", num2);
array1.add(object);
}
String[] keys = { "num1", "num2" };
sortASCE(array1, keys);
System.out.println(array1.toString());
}
}
Set<String> stationCodes=new HashSet<String>();
JSONArray tempArray=new JSONArray();
for(int i=0;i<yourJSONArray.size();i++){
String stationCode=yourJSONArray.getJSONObject(i).getString("stationCode");
if(stationsCodes.contains(stationCode){
continue;
}
else{
stationsCodes.add(stationCode);
tempArray.add(yourJSONArray.getJSONObject(i));
}
}
yourJSONArray= tempArray; //assign temp to original
//here how you can sort it using utility above:
JSONArraySort.sortASCE(yourJSONArray,"distance");
Here is the code for joining '2' JSONArrays and removing duplicates from the joined JSONArray, using ArrayList<String>..contains() method:
import java.util.ArrayList;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
/**
* @author RAM K K
* @gmail kkram523@gmail.com
*
*/
public class JSONOperations {
public static void main(String[] args) {
String s3;
String s1 = "[{\"name\": \"Bob\", \"car\": \"Ford\"},{\"name\": \"Steve\", \"car\": \"Mercedes Benz\"},{\"name\": \"Bob\", \"car\": \"Ford\"},{\"name\": \"Bob\", \"car\": \"Ford\"},{\"name\": \"Bob\", \"car\": \"Ford\"},{\"name\": \"Bob\", \"car\": \"Ford\"},{\"name\": \"Mary\", \"car\": \"Fiat\"}]";
String s2 = "[{\"name\": \"Mack\", \"car\": \"VW\"},{\"name\": \"Steve\", \"car\": \"Mercedes Benz\"},{\"name\": \"Bob\", \"car\": \"Ford\"}]";
try {
JSONArray sourceArray = new JSONArray(s2);
JSONArray destinationArray = new JSONArray(s1);
System.out.println(sourceArray);
System.out.println(destinationArray);
for (int i = 0; i < sourceArray.length(); i++) {
destinationArray.put(sourceArray.getJSONObject(i));
}
System.out.println(destinationArray);
System.out.println("JSONArray Size is: " + destinationArray.length());
List<String> list = new ArrayList<String>();
for (int i = 0; i < destinationArray.length(); i++) {
if (!list.contains(destinationArray.get(i).toString())) {
list.add(destinationArray.get(i).toString());
}
}
System.out.println("LIST: " + list);
System.out.println("LIST Size: " + list.size());
JSONArray distinctJSONArray = new JSONArray(list.toString());
System.out.println(distinctJSONArray.length());
for (int i = 0; i < distinctJSONArray.length(); i++) {
JSONObject JSON = (JSONObject) distinctJSONArray.getJSONObject(i);
System.out.println(JSON);
}
s1 = s1.substring(s1.indexOf("[") + 1, s1.lastIndexOf("]"));
s2 = s2.substring(s2.indexOf("[") + 1, s2.lastIndexOf("]"));
s3 = "[" + s1 + "," + s2 + "]";
System.out.println(new JSONArray(s3));
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}