如何使用Java从json文件中提取每个元素(书签)作为项目? [英] How to extract each element (Bookmark) from a json file as an item using Java?
问题描述
我正在尝试从Chrome的书签文件中提取书签，该文件以json格式存储.我有很多书签.下面的示例文件是一个新的Google配置文件，用于为一个可行的文件添加少量元素.
I’m trying to extract my bookmarks from Chrome’s bookmarks file, which is stored in the json format. I have a large number of bookmarks. This sample file below is a new Google profile to make a small number of elements for a workable file.
到目前为止，我已经构建了一个Java程序来遍历文件并提取密钥.我的问题是某些键是数组，并且在项目中有多个键.目前，我正在尝试弄清楚如何获取这些单独的元素.
So far I have constructed a java program to iterate through the file and extract the keys. My problem is that some of the keys are arrays and have multiple keys in the item. At present I’m trying to figure out how to get those individual elements.
每个书签都有唯一的ID标识.因此，如果我可以通过ID获得密钥，然后将密钥的其他每个元素与该唯一ID相关联，那么我相信我会拥有每个书签.
Each of the bookmarks are identified with a unique ID. So if I can get the key by ID, then associate each of the other elements of the key with that unique ID, I believe I’ll have each of the bookmarks.
我的最终目标是将书签放入数据库中，以便我可以更好地组织书签，例如搜索，查找重复项，分类和添加评论等.
My final objective is to put the bookmarks into a database so that I can have a better way of organizing them such as, searching, finding duplicates, categorizing and adding comments, etc.
我的Java程序如下.同样在Java程序下面的是在附加的Chrome书签文件上运行输出后的输出.
My java program is the below. Also below the java program is the output after running it on the attached Chrome bookmark file.
书签文件:
Bookmarks.json:
Bookmarks file:
Bookmarks.json:
{
"checksum": "d27be6b28b9a8879c2cb9ba6fc90df21",
"roots": {
"bookmark_bar": {
"children": [ {
"date_added": "13081990058553125",
"id": "7",
"meta_info": {
"stars.id": "ssc_c257c6390425956c",
"stars.version": "sync.server.Chrome45"
},
"name": "Google",
"sync_transaction_version": "1",
"type": "url",
"url": "https://www.google.com/"
}, {
"date_added": "13078166246742000",
"id": "9",
"meta_info": {
"stars.flags": "5",
"stars.id": "ssc_7150b291c6b52a37",
"stars.pageData": "Ig5keGVLcUJvcW5kTjZSTQ==",
"stars.type": "2"
},
"name": "Apollo III Communications",
"sync_transaction_version": "1",
"type": "url",
"url": "http://www.apollo3.com/"
} ],
"date_added": "13113606994595146",
"date_modified": "13083379523340359",
"id": "1",
"name": "Bookmarks bar",
"type": "folder"
},
"other": {
"children": [ ],
"date_added": "13113606994595154",
"date_modified": "0",
"id": "2",
"name": "Other bookmarks",
"type": "folder"
},
"sync_transaction_version": "5",
"synced": {
"children": [ ],
"date_added": "13113606994595157",
"date_modified": "0",
"id": "3",
"name": "Mobile bookmarks",
"type": "folder"
}
},
"version": 1
}
用于遍历并提取书签的Java程序:
getChromeBookmarks.java
Java Program to iterate through and extract the bookmarks:
getChromeBookmarks.java
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
public class getChromeBookmarks {
@SuppressWarnings("resource")
public static void main(String[] args) {
String infile = "/home/users/l/j/ljames/work/json/Bookmarks.json";
String content = null;
try {
content = new Scanner(new File(infile)).useDelimiter("\\Z").next();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
JSONParser parser = new JSONParser();
try {
JSONObject json = (JSONObject) parser.parse(content);
printJsonObject(json);
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void printJsonObject(JSONObject jsonObj) {
for (Object key : jsonObj.keySet()) {
// based on the key types
String keyStr = (String) key;
Object keyvalue = jsonObj.get(keyStr);
// Print key and value
System.out.println("key: " + keyStr + " value: " + keyvalue);
// expand(keyvalue);
// for nested objects iteration if required
if (keyvalue instanceof JSONObject)
printJsonObject((JSONObject) keyvalue);
}
}
}
java/jason程序的输出:
key: checksum value: d27be6b28b9a8879c2cb9ba6fc90df21
key: roots value: {"other":{"date_added":"13113606994595154","date_modified":"0","children":[],"name":"Other bookmarks","id":"2","type":"folder"},"synced":{"date_added":"13113606994595157","date_modified":"0","children":[],"name":"Mobile bookmarks","id":"3","type":"folder"},"bookmark_bar":{"date_added":"13113606994595146","date_modified":"13083379523340359","children":[{"date_added":"13081990058553125","meta_info":{"stars.id":"ssc_c257c6390425956c","stars.version":"sync.server.Chrome45"},"name":"Google","id":"7","type":"url","url":"https:\/\/www.google.com\/","sync_transaction_version":"1"},{"date_added":"13078166246742000","meta_info":{"stars.pageData":"Ig5keGVLcUJvcW5kTjZSTQ==","stars.id":"ssc_7150b291c6b52a37","stars.type":"2","stars.flags":"5"},"name":"Apollo III Communications","id":"9","type":"url","url":"http:\/\/www.apollo3.com\/","sync_transaction_version":"1"}],"name":"Bookmarks bar","id":"1","type":"folder"},"sync_transaction_version":"5"}
key: other value: {"date_added":"13113606994595154","date_modified":"0","children":[],"name":"Other bookmarks","id":"2","type":"folder"}
key: date_added value: 13113606994595154
key: date_modified value: 0
key: children value: []
key: name value: Other bookmarks
key: id value: 2
key: type value: folder
key: synced value: {"date_added":"13113606994595157","date_modified":"0","children":[],"name":"Mobile bookmarks","id":"3","type":"folder"}
key: date_added value: 13113606994595157
key: date_modified value: 0
key: children value: []
key: name value: Mobile bookmarks
key: id value: 3
key: type value: folder
key: bookmark_bar value: {"date_added":"13113606994595146","date_modified":"13083379523340359","children":[{"date_added":"13081990058553125","meta_info":{"stars.id":"ssc_c257c6390425956c","stars.version":"sync.server.Chrome45"},"name":"Google","id":"7","type":"url","url":"https:\/\/www.google.com\/","sync_transaction_version":"1"},{"date_added":"13078166246742000","meta_info":{"stars.pageData":"Ig5keGVLcUJvcW5kTjZSTQ==","stars.id":"ssc_7150b291c6b52a37","stars.type":"2","stars.flags":"5"},"name":"Apollo III Communications","id":"9","type":"url","url":"http:\/\/www.apollo3.com\/","sync_transaction_version":"1"}],"name":"Bookmarks bar","id":"1","type":"folder"}
key: date_added value: 13113606994595146
key: date_modified value: 13083379523340359
key: children value: [{"date_added":"13081990058553125","meta_info":{"stars.id":"ssc_c257c6390425956c","stars.version":"sync.server.Chrome45"},"name":"Google","id":"7","type":"url","url":"https:\/\/www.google.com\/","sync_transaction_version":"1"},{"date_added":"13078166246742000","meta_info":{"stars.pageData":"Ig5keGVLcUJvcW5kTjZSTQ==","stars.id":"ssc_7150b291c6b52a37","stars.type":"2","stars.flags":"5"},"name":"Apollo III Communications","id":"9","type":"url","url":"http:\/\/www.apollo3.com\/","sync_transaction_version":"1"}]
key: name value: Bookmarks bar
key: id value: 1
key: type value: folder
key: sync_transaction_version value: 5
key: version value: 1
更新:这是我尝试执行的示例，代码来自:
Update: This is an example of what I am trying to do, code from:
https://stackoverflow.com/a/40887240/1204365
import java.io.FileReader;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
public class Bookmark {
private static String jsonFile = "/home/users/l/j/ljames/.config/google-chrome/Default/Bookmarks";
public static void main(String[] args) {
// TODO Auto-generated method stub
FileReader reader = new FileReader(jsonFile); // access the file
JSONObject jsonObject = (JSONObject) new JSONParser().parse(reader);
String checksum = jsonObject.optString("checksum");
// get root object
JSONObject root = jsonObject.getJSONObject("roots");
// get root bookmarks object from root
JSONObject bookmarks = root.getJSONObject("bookmark_bar");
// get root children array from bookmarks
JSONArray childrens = bookmarks.getJSONArray("children");
JSONObject temp;
for (int i = 0; i < childrens.size(); i++) {
// get object using index from childrens array
temp = childrens.getJSONObject(i);
// get url
String url = temp.optString("url");
}
}
}
输出/错误为:
check: b8b257094128d165d7ccc70d0498cc87
Exception in thread "main" java.lang.ClassCastException: org.json.simple.JSONObject cannot be cast to org.json.simple.JSONArray
at javaTools.JsonParser.main(JsonParser.java:27)
Eclipse中有六个红色标记.它们在下面的行中.每行建议的修复方法与第一行相同(突出显示为黑体):
There are six red marks in Eclipse. They are on the lines below. The suggested fix for each line is the same as the first... (highlight in bold text):
Line 19: String checksum = jsonObject.optString("checksum");
Error: Suggesting:
Change to 'toJSONString(..)'
Add cast to 'temp'
Rename in file (Ctrl+2 R)
This same suggestion is repleated for the other five red error marks.
Line 22: JSONObject root = jsonObject.getJSONObject("roots");
Line 25: JSONObject bookmarks = root.getJSONObject("bookmark_bar");
Line 28: JSONArray childrens = bookmarks.getJSONArray("children");
Line 33: temp = childrens.getJSONObject(i);
Line 36: String url = temp.optString("url");
推荐答案
解析所有需要嵌套遍历的URL链接意味着在数组和对象内部可以存在嵌套数组.
The parsing all URL links required nested traversing mean there can be nested arrays inside arrays and object.
方法:
1.)我们将获取root元素内的所有键并遍历它们，以便首先解析对象
1.) we will fetch all the keys inside root element and traverse them so first parse the object
try {
jsonObject = (JSONObject) new JSONParser().parse(reader);
} catch (IOException | ParseException e) {
e.printStackTrace();
}
-
然后从所需的父元素(即
root)中获取所有键，并使用foreachloop遍历它们.Then fetch all the keys from required parent element i.e.
rootand traverse them usingforeachloop.JSONObject root = (JSONObject) jsonObject.get("roots"); // fetch all keys using keyset Set<String> set = root.keySet(); // traverse all keys using foreach loop for (String string : set) {
2.)遍历时，我们只是尝试将键转换为
jsonobject，并且如果键只是我们的json文件中的字符串，则将引发异常 string无法转换为JSONObject ，但是将为catched，因此不用担心2.) While traversing we simply try to convert key as
jsonobjectand if key simply is a string inside ourjsonfile then exception will be raised string cannot be converted to JSONObject but will becatchedso don't worryfor (String string : set) { try { obj = (JSONObject) root.get(string); } catch (ClassCastException e) { // no need to do anything here } }3.)如果它是
JSONObject，那么我们只需尝试找到实际上包含我们的url链接的children数组3.) If it's a
JSONObjectthen we simply try to find thechildrenarray which actually contains our urls linksif (obj.containsKey("children")) { try { childrens = (JSONArray) obj.get("children"); // call to recursive function to find nested children array //and print url printUrls(childrens); } catch (Exception e) { // try-catch to handle any unexpected case } }4.)现在是嵌套数组部分，因为任何子代都可以包含嵌套的
children数组，所以我应用了递归的概念来查找和获取嵌套数组的内容4.) Now the nested array part , since any children can contain nested
childrenarrays so i applied the concept of recursion to find and fetch content of nested arrayspublic static void printUrls(JSONArray childrens) { JSONObject temp = null; for (int i = 0; i < childrens.size(); i++) { // get object using index from children array temp = (JSONObject) childrens.get(i); // check if it contains any nested children array key // if yes then , fetch the nested children array and call this funtion // again to print it's content if (temp.containsKey("children")) { printUrls((JSONArray) temp.get("children")); } // fetch and print the url , most wanted guy here String url = (String) temp.get("url"); if (url != null) { // display the url using print System.out.println(url); // count is a variable which will be incremented when any url found // and total of found urls , will be displayed at the end of parsing count++; } } }Org.JSON jar链接 > :单击链接中的
download jar选项和/或将其添加为项目中的依赖项Org.JSON jar link : click
download jaroption in the link and/or add it as a dependency jar in your project代码
import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.util.Objects; import java.util.Optional; import java.util.Set; import org.json.simple.JSONArray; import org.json.simple.JSONObject; import org.json.simple.parser.JSONParser; import org.json.simple.parser.ParseException; // parsing code using json.simple public class Test2 { // path to your file private static String jsonFile = "C:\\bookmarks.json"; static int count = 0; public static void main(String[] args) { // a file reader class to access the file using string file path FileReader reader = null; try { reader = new FileReader(jsonFile); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } // access the file JSONObject jsonObject = null; try { jsonObject = (JSONObject) new JSONParser().parse(reader); } catch (IOException | ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } String checksum = (String) jsonObject.get("checksum"); JSONObject root = (JSONObject) jsonObject.get("roots"); Set<String> set = root.keySet(); JSONArray childrens = null; JSONObject obj = null; for (String string : set) { try { obj = (JSONObject) root.get(string); } catch (ClassCastException e) { } if (obj.containsKey("children")) { try { childrens = (JSONArray) obj.get("children"); printUrls(childrens); } catch (Exception e) { } } } // display , how many urls we have found System.out.println("count is " + count); } public static void printUrls(JSONArray childrens) { JSONObject temp = null; for (int i = 0; i < childrens.size(); i++) { // get object using index from childrens array temp = (JSONObject) childrens.get(i); if (temp.containsKey("children")) { printUrls((JSONArray) temp.get("children")); } // get url String url = (String) temp.get("url"); if (url != null) { System.out.println(url); count++; } } } }输出:OP提供的链接具有2521个URL，因此无法全部发布，但计数值应该足够了
Output : The link provided by OP has 2521 urls so can't post all but count value should be enough
... http://www.team-cymru.org/bogon-reference-http.html http://www.team-cymru.org/bogon-reference-bgp.html http://www.team-cymru.org/Services/Bogons/fullbogons-ipv4.txt http://tecadmin.net/enable-logging-in-iptables-on-linux/# https://www.youtube.com/watch?v=geglU1AdmJs&t=480s count is 2521这篇关于如何使用Java从json文件中提取每个元素(书签)作为项目?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
