package com.xmage.ws.util.json;
import net.minidev.json.JSONArray;
import net.minidev.json.JSONObject;
import net.minidev.json.JSONValue;
import java.util.HashMap;
import java.util.Map;
/**
* Enhances working with json.
*
* @author noxx
*/
public class JSONParser {
public enum CachePolicy {
CACHE_ONE_LEVEL_ONLY,
CACHE_ALL_LEVELS
}
private static final Map<String, Integer> extendedIndexes = new HashMap<String, Integer>() {{
put("$first", 0);
put("$second", 1);
put("$third", 2);
put("$fourth", 3);
put("$fifth", 4);
}};
private String json;
private JSONObject root;
private boolean hitCache;
private CachePolicy cachePolicy = CachePolicy.CACHE_ONE_LEVEL_ONLY;
private Map<String, Object> cache = new HashMap<String, Object>();
public void parseJSON(String jsonString) throws JSONValidationException {
parseJSON(jsonString, true);
}
public void parseJSON(String jsonString, boolean validate) throws JSONValidationException {
this.json = jsonString;
prepare();
if (validate) {
validate();
}
}
public Object get(String path) {
return getObject(path);
}
public int getInt(String path) {
return (Integer)getObject(path);
}
public int getIntSafe(String path) {
if (getObject(path) == null) {
return 0;
}
return (Integer)getObject(path);
}
public String getString(String path) {
return (String)getObject(path);
}
public JSONObject getJSON(String path) {
return (JSONObject)getObject(path);
}
private Object getObject(String path) {
this.hitCache = false;
if (cache.containsKey(path)) {
this.hitCache = true;
return cache.get(path);
}
String[] params = path.split("\\.");
JSONObject json = this.root;
JSONArray jsonArray = null;
String currentPath = "";
for (int i = 0; i < params.length - 1; i++) {
String param = params[i];
if (cachePolicy.equals(CachePolicy.CACHE_ALL_LEVELS)) {
if (!currentPath.isEmpty()) {
currentPath += ".";
}
currentPath += param;
}
if (param.startsWith("$")) {
if (jsonArray == null) {
throw new JSONOperationErrorException("Not illegal syntax at this place: " + param);
}
int index = getIndex(param);
json = (JSONObject) jsonArray.get(index);
jsonArray = null;
} else if (param.contains("[")) {
int find = param.indexOf("[");
String newParam = param.substring(0, find);
String s = param.substring(find+1, param.indexOf("]"));
if (s.isEmpty()) {
jsonArray = (JSONArray) json.get(newParam);
json = null;
} else {
int index = Integer.parseInt(s);
json = (JSONObject)((JSONArray) json.get(newParam)).get(index);
jsonArray = null;
}
} else {
Object obj = json.get(param);
if (obj instanceof JSONObject) {
json = (JSONObject) obj;
jsonArray = null;
} else if (obj instanceof JSONArray) {
jsonArray = (JSONArray) obj;
json = null;
} else if (obj == null) {
throw new IllegalStateException("json object is null");
} else {
throw new IllegalStateException("json object ('"+param+"') has wrong type: " + obj.getClass());
}
}
if (cachePolicy.equals(CachePolicy.CACHE_ALL_LEVELS)) {
saveToCache(currentPath, json);
}
}
String name = params[params.length - 1];
Object value;
if (name.startsWith("$")) {
if (jsonArray == null) {
throw new JSONOperationErrorException("Not illegal syntax at this place: " + name);
}
int index = getIndex(name);
value = jsonArray.get(index);
} else {
value = json.get(name);
}
saveToCache(path, value);
return value;
}
private int getIndex(String extendedIndex) {
if (extendedIndexes.containsKey(extendedIndex)) {
return extendedIndexes.get(extendedIndex);
} else {
throw new JSONOperationErrorException("Can't parse extended index: " + extendedIndex);
}
}
private void saveToCache(String path, Object value) {
cache.put(path, value);
}
public JSONArray getJSONArray(String path) {
return (JSONArray)getObject(path);
}
private void prepare() {
reset();
if (this.json != null) {
this.json = this.json.trim();
}
}
private void validate() throws JSONValidationException {
if (this.json == null) {
throw new JSONValidationException("JSON is null");
}
try {
this.root = (JSONObject) JSONValue.parse(this.json);
if (this.root == null) {
throw new JSONValidationException("Root json is null");
}
} catch (Exception e) {
throw new JSONValidationException("JSON is not valid", e);
}
}
public void reset() {
this.hitCache = false;
this.cachePolicy = CachePolicy.CACHE_ONE_LEVEL_ONLY;
this.cache.clear();
}
public boolean isHitCache() {
return hitCache;
}
public void setCachePolicy(CachePolicy cachePolicy) {
this.cachePolicy = cachePolicy;
}
}