We can use .extract then .jsonPath and lastly getString("token")
String myToken = given() .log().all() .contentType(ContentType.URLENC) .formParam("email","xxxxxxxxxxx") .formParam("password","xxxxxxx") .when() .post("/login") .then() .log().all() .statusCode(200) .body("token", is(notNullValue())) .contentType(ContentType.JSON) .body("token",is(not(emptyString()))) .extract() .jsonPath() .getString("token") ;