我正在尝试根据运行时给出的规范在 java 中实现 JSON 到 JSON 的转换。
示例：如果在运行时 source : com.gsdetails.gname,target : com.track.trackName （即源字段应映射到生成的 JSON 中的目标字段）
我的方法是为规范部分创建 N 数组树并进行广度优先遍历（使用它获取队列以创建结果 json 的结构）我正在使用 Jackson api 从输入 JSON 创建树并遍历队列（bfs）和输入树来创建结果 json。
无法获得预期的输出
PS：我想过使用 JOLT api，但它不符合我的目的
树（用于规范）
public class TrieBuilder {
public static void main(String[] args) throws Exception {
createSpec();
}
public static Trie createSpec() throws Exception {
BufferedReader reader = new BufferedReader(
new FileReader(""));
String currentLine = reader.readLine();
Trie trie = new Trie();
while (currentLine != null) {
String[] lines = currentLine.split(",");
String sourceLine = lines[0];
String targetLine = lines[1];
String sourcePath = sourceLine.split("=")[1];
String targetPath = targetLine.split("=")[1];
trie.insertWord(sourcePath.trim(), targetPath.trim());
currentLine = reader.readLine();
}
return trie;
}
}
class TrieNode {
String source;// consider this as content/reference point of a tree
String target;
boolean isEnd;
int count;
List childList;
boolean isRoot;
/* Constructor */
public TrieNode(String source, String target) {
childList = new ArrayList<TrieNode>();
isEnd = false;
count = 0;
this.source = source;
this.target = target;
}
public TrieNode subNodeWord(String word) {
if (childList != null) {
for (TrieNode eachChild : childList)
if (eachChild.source.equals(word))
return eachChild;
}
return null;
}
}
class Trie {
public TrieNode root;
/* Constructor */
public Trie() {
root = new TrieNode("", "");
}
public void insertWord(String sourceWords, String targetWords) {
if (searchWord(sourceWords) == true)
return;
TrieNode current = root;
String[] sourceArray = sourceWords.split(":");
String[] targetArray = targetWords.split(":");
for (int i = 0; i < sourceArray.length; i++) {
TrieNode child = current.subNodeWord(sourceArray[i]);
if (child != null) {
current = child;
} else {
current.childList.add(new TrieNode(sourceArray[i],
targetArray[i]));
current = current.subNodeWord(sourceArray[i]);
}
current.count++;
}
current.isEnd = true;
}
public boolean searchWord(String words) {
TrieNode current = root;
for (String word : words.split(":")) {
if (current.subNodeWord(word) == null) {
return false;
} else {
current = current.subNodeWord(word);
}
}
if (current.isEnd == true)
return true;
return false;
}
public Queue<TrieNode> bfsTraversal(TrieNode node) {
// TODO need to add logic for bfs/dfs for traversing the trie
Queue<TrieNode> queue = new LinkedList<>();
Queue<TrieNode> tempQueue = new LinkedList<>();
queue.add(root);
while (!queue.isEmpty()) {
TrieNode tempNode = queue.poll();
tempQueue.add(tempNode);
int counter = tempNode.childList.size(), i = 0;
if (tempNode == null)
break;
if (!tempNode.source.isEmpty())
System.out.println("Source :" + tempNode.source
+ " Target : " + tempNode.target);
while (i < counter) {
queue.add(tempNode.childList.get(i++));
}
}
tempQueue.poll();
return tempQueue;
}
源到目标映射文件：
source = com:track:trackDetails:fname, target = gsUser:gsProp:gsDetails:gsFirstName
source = com:track:trackDetails:lname, target = gsUser:gsProp:gsDetails:gsLastName
助手类（实际转换）：
public class JsonHelperClass{
// private Files file = null;// create a tempfile
private JsonNodeFactory factory;
private JsonFactory jsonFactory;
private ObjectMapper mapper;
private JsonNode jsonRoot;
private Queue<TrieNode> queue;
// private JsonParser jsonParser =
public JsonHelperClass() throws JsonProcessingException, IOException {
this.factory = JsonNodeFactory.instance;
this.jsonFactory = new JsonFactory();
this.mapper = new ObjectMapper();
this.jsonRoot = mapper.readTree(new File("json with data"));
}
public static void main(String[] args) throws Exception, Exception {
JsonHelperClass helperClass = new JsonHelperClass();
helperClass.jsonCreator();
ObjectNode objectNode = null;
ObjectNode result = helperClass.createJsonRecursively(objectNode);
System.out.println(result.toString());
}
public void jsonCreator() throws Exception {
Trie trie = TrieBuilder.createSpec();
queue = trie.bfsTraversal(trie.root);
}
public ObjectNode createJsonRecursively(ObjectNode outputJson) throws Exception {
TrieNode nodeOfQueue = queue.poll();
if(outputJson == null){
// create a root of the JSON
outputJson = factory.objectNode();
outputJson.put(nodeOfQueue.target, createJsonRecursively(outputJson));
}else if (jsonRoot.get(nodeOfQueue.source).isObject()){
// create an object to conatin other values/object
ObjectNode objectNode = factory.objectNode();
objectNode.put(nodeOfQueue.target,createJsonRecursively(outputJson));
outputJson.putAll(objectNode);
}else if(jsonRoot.get(nodeOfQueue.source).isArray()){
// create an array node and call for to create value it contains
ArrayNode arrayNode = factory.arrayNode();
int size = jsonRoot.get(nodeOfQueue.source).size();
for(int index = 0 ; index < size ; index++){
arrayNode.add(jsonRoot.get(nodeOfQueue.source).get(index));
}
outputJson.put(nodeOfQueue.target,arrayNode);
}else if(nodeOfQueue.isEnd){
// create leaf node
outputJson.put(nodeOfQueue.target, jsonRoot.get(nodeOfQueue.source));
return outputJson;
}
return outputJson;
}