What is the best way to iterate through all values in a LinkedTreeMap with the keys as Strings and the values as

Question

What is the best way to iterate through all values in a LinkedTreeMap with the keys as Strings and the values as

I am facing an issue where I have a JSON file and all the data is stored in a LinkedTreeMap<String, Object>. The problem arises when one of the JSON fields becomes complex:

{
    "val1": "1",
    "val2": "2",
    "val3": {
        "embVal1": "emb1",
        "embVal2": emb2
    },
    "val4": "4"
}

For example, if val3 is a complex field, then mapping it with an Object type will require transforming it into another

LinkedTreeMap<String, Object>

, resulting in my structure to look like

LinkedTreeMap<String, LinkedTreeMap<Sting, Object>>

.

If val3 contains other complex objects within it, then the value of Object type will also need to be transformed into a new

LinkedTreeMap<String, Object>

, continuing recursively as we delve deeper into the JSON tree.

The challenge now is how can I efficiently traverse all embedded nodes in a structure like this?

java json collections treemap

Answer 1

Answer №1

Here is the code snippet that I put together without much focus on performance, but it functions effectively

AppTest.java

public class AppTest {
    
    @Test
    public void testApp() {
        LinkedTreeMap<String, Object> node = new LinkedTreeMap<>();
        LinkedTreeMap<String, Object> node2 = new LinkedTreeMap<>();
        LinkedTreeMap<String, Object> node3 = new LinkedTreeMap<>();
        
        node2.put("embembVal1", "embemb1");
        node2.put("embembVal2", "embemb2");
        
        node3.put("embVal1", "emb1");
        node3.put("embVal2", node2);
        
        node.put("val1", "1");
        node.put("val2", "2");
        node.put("val3", node3);
        node.put("val4", "4");
        
        MyJson json = new MyJson();
        json.read(node);
        
        System.out.println(MyJsonBuilder.build());
    }

}

MyJson.java

public class MyJson {
    
    public void read(LinkedTreeMap<String, Object> node) {
        MyJsonBuilder.append("{");
        
        for(Entry<String, Object> set : node.entrySet()) {
            if(!getInstanceType(set.getValue())) {
                jsonFormat(set.getKey(), set.getValue());
            } else {
                new MyJson().read( (LinkedTreeMap<String, Object>) set.getValue() );
            }
        }
        
        MyJsonBuilder.append("}");
    }
    
    private void jsonFormat(String k, Object v) {
        MyJsonBuilder.append( String.format("\"%s\":\"%s\"", k, v) );
    }
    
    private boolean getInstanceType(Object obj) {
        if(obj instanceof LinkedTreeMap) return true;
        else return false;
    }
   
}

MyJsonBuilder.java

public class MyJsonBuilder {
    
    private static StringBuilder jsonBuilder = new StringBuilder();
    
    public static void append(String node) {
        jsonBuilder.append(node);
    }
    
    private static String format(String json) {
        String adjustedjson = json;
        if (adjustedjson.contains("\"\"")) adjustedjson = adjustedjson.replaceAll("\"\"", "\",\"");
        if (adjustedjson.contains("}\"")) adjustedjson = adjustedjson.replaceAll("}\"", "},\"");
        
        return adjustedjson;
    }
    
    public static String build() {
        return format(jsonBuilder.toString());
    }
    
}

Answer 2

Here is the code snippet that I put together without much focus on performance, but it functions effectively

AppTest.java

public class AppTest {
    
    @Test
    public void testApp() {
        LinkedTreeMap<String, Object> node = new LinkedTreeMap<>();
        LinkedTreeMap<String, Object> node2 = new LinkedTreeMap<>();
        LinkedTreeMap<String, Object> node3 = new LinkedTreeMap<>();
        
        node2.put("embembVal1", "embemb1");
        node2.put("embembVal2", "embemb2");
        
        node3.put("embVal1", "emb1");
        node3.put("embVal2", node2);
        
        node.put("val1", "1");
        node.put("val2", "2");
        node.put("val3", node3);
        node.put("val4", "4");
        
        MyJson json = new MyJson();
        json.read(node);
        
        System.out.println(MyJsonBuilder.build());
    }

}

MyJson.java

public class MyJson {
    
    public void read(LinkedTreeMap<String, Object> node) {
        MyJsonBuilder.append("{");
        
        for(Entry<String, Object> set : node.entrySet()) {
            if(!getInstanceType(set.getValue())) {
                jsonFormat(set.getKey(), set.getValue());
            } else {
                new MyJson().read( (LinkedTreeMap<String, Object>) set.getValue() );
            }
        }
        
        MyJsonBuilder.append("}");
    }
    
    private void jsonFormat(String k, Object v) {
        MyJsonBuilder.append( String.format("\"%s\":\"%s\"", k, v) );
    }
    
    private boolean getInstanceType(Object obj) {
        if(obj instanceof LinkedTreeMap) return true;
        else return false;
    }
   
}

MyJsonBuilder.java

public class MyJsonBuilder {
    
    private static StringBuilder jsonBuilder = new StringBuilder();
    
    public static void append(String node) {
        jsonBuilder.append(node);
    }
    
    private static String format(String json) {
        String adjustedjson = json;
        if (adjustedjson.contains("\"\"")) adjustedjson = adjustedjson.replaceAll("\"\"", "\",\"");
        if (adjustedjson.contains("}\"")) adjustedjson = adjustedjson.replaceAll("}\"", "},\"");
        
        return adjustedjson;
    }
    
    public static String build() {
        return format(jsonBuilder.toString());
    }
    
}

What is the best way to iterate through all values in a LinkedTreeMap with the keys as Strings and the values as

Answer №1

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