Targeting S+ (version 31 and above)

how can i use it in android java ?

Targeting S+ (version 31 and above) requires that one of FLAG_IMMUTABLE or FLAG_MUTABLE be specified when creating a PendingIntent.
Strongly consider using FLAG_IMMUTABLE, only use FLAG_MUTABLE if some functionality depends on the PendingIntent being mutable, e.g. if it needs to be used with inline replies or bubbles.
at android.app.PendingIntent.checkFlags(PendingIntent.java:375)
at android.app.PendingIntent.getBroadcastAsUser(PendingIntent.java:645)
at android.app.PendingIntent.getBroadcast(PendingIntent.java:632)
at org.eclipse.paho.android.service.AlarmPingSender.start(AlarmPingSender.java:76)
at org.eclipse.paho.client.mqttv3.internal.ClientState.connected(ClientState.java:1214)
at org.eclipse.paho.client.mqttv3.internal.ClientState.notifyReceivedAck(ClientState.java:1050)
at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:151)

Start at org.eclipse.paho.android.service.AlarmPingSender.start in AlarmPingSender.java, especially line 76, and inspect the PendingIntent creation shown in the stack trace. Check the Android PendingIntent requirements for targeting version 31 and above; done means the reported exception no longer occurs for that path.

Written by the indexing model from the issue text.