How to convert data in Java List to List

Java List<JSONObject>Data Conversion List<T>

Inferring from the function of the method,TIt should be a specific Java Bean type, used toList<JSONObject>The data in theList<T>。

The following is a detailed introduction to how to pass genericsTAnd how to implement this method.

import ;
import ;
import ;

// Define a general conversion methodpublic class GenericConverter {
    public static &lt;T&gt; List&lt;T&gt; convertParamsBean(Class&lt;T&gt; clazz, List&lt;JSONObject&gt; jsonObjectList) {
        List&lt;T&gt; resultList = new ArrayList&lt;&gt;();
        for (JSONObject jsonObject : jsonObjectList) {
            try {
                // Use FastJSON to convert JSONObject to an object of the specified type                T instance = (jsonObject, clazz);
                (instance);
            } catch (Exception e) {
                ();
            }
        }
        return resultList;
    }
}

// Define an example Bean classclass ExampleBean {
    private String name;
    private int age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
         = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
         = age;
    }

    @Override
    public String toString() {
        return "ExampleBean{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

public class Main {
    public static void main(String[] args) {
        List&lt;JSONObject&gt; jsonObjectList = new ArrayList&lt;&gt;();

        // Create example JSONObject        JSONObject jsonObject1 = new JSONObject();
        ("name", "Alice");
        ("age", 25);
        (jsonObject1);

        JSONObject jsonObject2 = new JSONObject();
        ("name", "Bob");
        ("age", 30);
        (jsonObject2);

        // Call the conversion method and pass the Class object of the ExampleBean class        List&lt;ExampleBean&gt; exampleBeanList = (, jsonObjectList);

        // Print the converted result        for (ExampleBean bean : exampleBeanList) {
            (bean);
        }
    }
}

Code explanation

convertParamsBean method：

This method uses generics<T>, receive oneClass<T>Parameters of typeclazzAnd oneList<JSONObject>Parameters of typejsonObjectList。
TraversaljsonObjectList,useMethod to eachJSONObjectConvert toclazzThe object of the type represented.
Add the converted object toresultListand finally return to the list.

ExampleBean kind：

This is an example Java Bean class containingnameandageTwo attributes, and correspondinggetterandsettermethod.

Main Classicmain method：

Create aList<JSONObject>And add two examplesJSONObject。
CallMethod, deliveryAsclazzParameters,List<JSONObject>Convert toList<ExampleBean>。
Iterate over and print the convertedList<ExampleBean>。

Passing genericsTWay

CallingconvertParamsBeanWhen passing the specific Java Bean class when using the methodClassObjects, e.g.。
This way, this can be used inside the methodClassobject to create an instance of the corresponding type andJSONObjectThe data in the instance is populated.

Things to note

To ensure that the JSON processing library used (such as FastJSON) has been properly added to the project dependencies.
The target Java Bean class must have a default parameterless constructor becausetoJavaObjectMethods create objects using reflection.
ifJSONObjectThe field name in the Java Bean class does not match the attribute name and may require additional configuration or processing.

Summarize

The above is personal experience. I hope you can give you a reference and I hope you can support me more.