as Bozho said create class structure that reflacts JSON and then use jacson library as follow:
refer Parsing JSON File Java
ObjectMapper mapper = new ObjectMapper();
Projects projs =
mapper.readValue(new File("projects.json"),Projects.class);
ArrayList projects = projs.get("projects");
for (Project p : projects) {
ArrayList description = p.getDescription();
for (String s : description) {
System.out.println(s);