Hi All
I have created a page for entering multiple record at a time.if i am entering duplicate master code then its showing error message like this


 

public class MasterTestEntryPage1
{
    public String message = System.CurrentPagereference().getParameters().get('msg');
    public List<AccountWrapper> wrappers {get; set;}
    public List<AccountWrapper> wrappers1 {get; set;}
    public List<MasterTest__c> master {get; set;}
    public List<BankBookTest__c> bankbook {get; set;}    
    public static Integer toDelIdent {get; set;}
    public static Integer addCount {get; set;}
    private Integer nextIdent=1;    
    
    public MasterTestEntryPage1(){
        wrappers=new List<AccountWrapper>();
        Wrappers1=new List<AccountWrapper>();
        for (Integer idx=0; idx<1; idx++){
            wrappers.add(new AccountWrapper(nextIdent++));
            wrappers1.add(new AccountWrapper(nextIdent++));
                    
        }
    }
 public void delWrapper(){
        Integer toDelPos=-1;
        for (Integer idx=0; idx<wrappers.size(); idx++){
           if (wrappers[idx].ident==toDelIdent){
                toDelPos=idx;
            }
        }        
        if (-1!=toDelPos){
            wrappers.remove(toDelPos);
            
        }
        }
 
 /* public void delWrapper()
{
    Integer toDelPos = -1;
    for( Integer idx = 0; idx < wrappers.size(); idx++ )
    {
        if( wrappers[idx].ident == toDelIdent )
        {
            toDelPos = idx;
        }
    }       

    if( toDelPos != -1 )
    {
        MasterTest__c bk = wrappers.get( toDelPos ).acc;
        wrappers.remove( toDelPos );
        
        delete bk;
    }
} */
    

    public void addRows(){
    
    List<MasterTest__c> accs=new List<MasterTest__c>();
        for (AccountWrapper wrap : wrappers){
            accs.add(wrap.acc);
        }        
        
    
        AccountWrapper objAccWrapper;
        for (Integer idx=0; idx<addCount; idx++){
            objAccWrapper = new AccountWrapper(nextIdent++);
            if(!wrappers.isEmpty()){
                objAccWrapper.acc.Date__c= wrappers[0].acc.Date__c;
                
                
            }
            wrappers.add(objAccWrapper);
        }
    }

 public PageReference save(){
  try{
  List<MasterTest__c> accs=new List<MasterTest__c>();
  for (AccountWrapper wrap : wrappers)
  {
  
   accs.add(wrap.acc);
   
  }
   insert accs;
  
  return new PageReference('/' + Schema.getGlobalDescribe().get('MasterTest__c').getDescribe().getKeyPrefix() + '/o');
  
  }
  
  catch(Exception e)
        {  
        //ApexPages.Message myMsg = new  ApexPages.Message(ApexPages.Severity.ERROR,'Sorry...... You have entered DUPLICATE MASTER CODE' );
           // ApexPages.addMessage(myMsg); 
         
           Apexpages.addMessage(new Apexpages.message(ApexPages.Severity.Error,' The code is duplicate or invalid. '));
       } 
 

        return null; 
  }
    public pageReference parentPage () {

          return new pageReference('/apex/MasterDetailsPage');
} 
    public class AccountWrapper{
        public MasterTest__c acc {get; private set;}
        public Integer ident {get; private set;}
        public AccountWrapper(Integer inIdent){
            ident=inIdent;
            acc=new MasterTest__c();
        }
    }
}

<apex:page controller="MasterTestEntryPage1" tabstyle="Account" showHeader="true" sidebar="false">

<apex:pageMessages id="showmsg" ></apex:pageMessages>
<apex:define name="body">


<script type="text/javascript">
function displaymessage()
{
alert("Remember to Delete blank row that you have made!");
}
</script>
            
            <div style="width:1000px;margin: 0px auto 10px auto;background-color:Gray;border: 1px solid black;">
             <apex:image id="theImage" value="{!$Resource.Emami}" width="100" height="100"/>
             <apex:outputLink style="font-weight: bold;float:right;" value="{!URLFOR($Page.LoginPage)}"><b>Back To Home</b></apex:outputLink>
 <apex:form >
   <apex:pageBlock title="Master Entry:">
   <apex:pageBlockSection columns="1"  ><h1><marquee>PLEASE ENTER DATE BEFORE CREATING MASTERS !!</marquee></h1>
       <apex:pageBlockTable value="{!wrappers}" var="wrapper"  style="width:70px;" >
                    <apex:column headerValue="Opening Balances as on"   >
                            <apex:inputField value="{!wrapper.acc.Date__c}"  required="true" />
                      </apex:column>
     </apex:pageBlockTable>
    
      <apex:pageBlockTable value="{!wrappers}" var="wrapper" id="wtable" >
      
      <apex:column headerValue="">
            <apex:commandButton value="X" action="{!delWrapper}" rerender="wtable" style="background:red">
               <apex:param name="toDelIdent" value="{!wrapper.ident}" assignTo="{!toDelIdent}"/> 
            </apex:commandButton>
         </apex:column>
        <!--  <apex:column headerValue="Sl.No" style="background:pink;">
            <apex:outputText value="{!wrapper.ident}"/>
         </apex:column> -->
         <apex:column headerValue="Select Account" style="background:pink;">
            <!-- <apex:inputField value="{!wrapper.acc.Type__c}" /> -->
            <apex:selectList multiselect="false" size="1" value="{!wrapper.acc.Type__c}" onchange="showButton()">             
                <apex:selectOption itemvalue="Party Account" itemLabel="Party Account"/>
                <apex:selectOption itemvalue="Bank Account" itemLabel="Bank Account"/>                                
            </apex:selectList>
         </apex:column>
        

         <apex:column headerValue="Master Code" style="background:pink;">
            <apex:inputField value="{!wrapper.acc.Name}" />
         </apex:column>
          <apex:column headerValue="Master Name" style="background:pink;">
            <apex:inputField value="{!wrapper.acc.Master_Code__c}"  />
         </apex:column>
                  <apex:column headerValue="Opening Balance" style="background:pink;">
         
                        <apex:inputField value="{!wrapper.acc.Opening_Balance__c}"/>
                   
            
         </apex:column>
         
         <apex:column headerValue="Remarks" style="background:pink;">
            <apex:inputField value="{!wrapper.acc.Remarks__c}"/>
         </apex:column>
       
        
       
       <apex:column headerValue="">
            <apex:commandButton value="Enter" action="{!addRows}" rerender="wtable" style="background:pink" >
         <apex:param name="addCount" value="1" assignTo="{!addCount}"/> 
      </apex:commandButton>
         </apex:column>
       
        
      </apex:pageBlockTable>
      </apex:pageBlockSection>
      <apex:commandButton value="Add 5 Rows" action="{!addRows}" rerender="wtable">
         <apex:param name="addCount" value="5" assignTo="{!addCount}"/> 
      </apex:commandButton>
       <apex:commandButton value="View Master List" action="{!parentPage }" rerender="wtable">
          
      </apex:commandButton>
      <apex:commandButton value="Save Master" action="{!save}"  />
   </apex:pageBlock>
 </apex:form>
  </div>
        </apex:define>
        
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    </center><br/>
</apex:page>