how to generate payUmoney key hash i am new in android

public void generateHash(HashMap<String, String> valueMap, PayUHashGenerationListener hashGenerationListener) { String hashName = valueMap.get(PayUCheckoutProConstants.CP_HASH_NAME); String hashData = valueMap.get(PayUCheckoutProConstants.CP_HASH_STRING); if (!TextUtils.isEmpty(hashName) && !TextUtils.isEmpty(hashData)) { //Do not generate hash from local, it needs to be calculated from server side only. Here, hashString contains hash created from your server side. String hash = hashString;

                        HashMap<String, String> dataMap = new HashMap<>();
                        dataMap.put(hashName, hash);
                        hashGenerationListener.onHashGenerated(dataMap);
                    }
                }