MyActivity.java

Intent intent = new Intent(this, NextActivity.class);
intent.putExtra("EXNAME", "example");
intent.putExtra("EXINT", 30);
startActivity(intent);

NextActivity.java

Intent intent = getIntent();
String exname = intent.getStringExtra("EXNAME");
int exint = intent.getIntExtra("EXINT", [デフォルト値]);