custom apex rest api

MyRestResource.apxc.java

@RestResource(urlMapping='/Teams/*')
global with sharing class MyRestResource {
  
	@HttpGet
    global static List<Team__c> getTeamById() {
        RestRequest request = RestContext.request;
        RestResponse res = RestContext.response;
        // grab the caseId from the end of the URL
        String teamId = request.requestURI.substring(
          request.requestURI.lastIndexOf('/')+1);
        List<Team__c> result = null;
        
        if (teamId.length()>0){
            // search by TeamId
            result = [SELECT Name, LeaderId__c, CreatedById, LastModifiedById
                        FROM Team__c
                        WHERE Id = :teamId];
        }else{
            // select all
            result = [SELECT Name, LeaderId__c, CreatedById, LastModifiedById
                        FROM Team__c];
        }
        return result;
    }
  
  @HttpPost
    global static Team__c createTeam(String name, String LeaderId) {
        
            if (name == null ){
                throw new ApexException('Name is required.');
            }
            if (name.length()==0){
                throw new ApexException('Name is required.');
            }
            Team__c newTeam = new Team__c();
            newTeam.Name = name;
            newTeam.LeaderId__c = LeaderId;
            insert newTeam;
            return newTeam;
    }
    
    @HttpPut
    global static Team__c putTeam(String id, String name, String leaderId){
        
        boolean isNullId = False;
        boolean isNullName = False;
        
        // check required
        if (name == null ){
                isNullName = True;
        }else{
            if (name.length()<=0) isNullName = True;
        }
        if (id ==null){
            isNullId = True;
        }else{
            if (id.length()<=0) isNullId = True; 
        }
        if (isNullId && isNullName){
            throw new ApexException('Id or Name is required.');
        }
        Team__c newTeam = new Team__c(
        	Id = id,
            Name = name,
            LeaderId__c = leaderId
        );
        if (!isNullId){
            // update or insert by TeamId
        	upsert newTeam;	
        }else{
            //update or insert by name
            upsert newTeam name; 	
        }
        return newTeam;
    }
    
    @HttpPatch
    global static Team__c updateTeam(){
        RestRequest req = Restcontext.request;
        String id = req.requestURI.substring(req.requestURI.lastIndexOf('/')+1);
        if (id == null ){
            throw new ApexException('Id is required.');
        }
        if (id.length()==0){
            throw new ApexException('Id is required.');
        }
        Team__c thisTeam = [SELECT Id FROM Team__c WHERE Id = :id];
        // Deserialize 
        Map<String, Object> params = (Map<String, Object>)JSON.deserializeUntyped(req.requestBody.tostring());
        for(String field : params.keySet()){
            thisTeam.put(field, params.get(field));
        }
        update thisTeam;
        return thisTeam;
    }
    
    @HttpDelete
    global static void deleteTeam() {
        RestRequest req = RestContext.request;
        RestResponse res = RestContext.response;
        String id = req.requestURI.substring(req.requestURI.lastIndexOf('/')+1);
        Team__c team = [SELECT Id FROM Team__c WHERE Id = :id];
        delete team;
    }
}