java-tutorials/json-2/src/main/java/com/baeldung/jsontojavaclass/JsonToJavaClassConversion.java

package com.baeldung.jsontojavaclass;

import java.io.File;
import java.io.IOException;
import java.net.URL;

import org.jsonschema2pojo.DefaultGenerationConfig;
import org.jsonschema2pojo.GenerationConfig;
import org.jsonschema2pojo.Jackson2Annotator;
import org.jsonschema2pojo.SchemaGenerator;
import org.jsonschema2pojo.SchemaMapper;
import org.jsonschema2pojo.SchemaStore;
import org.jsonschema2pojo.SourceType;
import org.jsonschema2pojo.rules.RuleFactory;

import com.sun.codemodel.JCodeModel;

public class JsonToJavaClassConversion {

    public static void main(String[] args) {
        String packageName = "com.baeldung.jsontojavaclass.pojo";
        String basePath = "src/main/resources";
        File inputJson = new File(basePath + File.separator + "input.json");
        File outputPojoDirectory = new File(basePath + File.separator + "convertedPojo");
        outputPojoDirectory.mkdirs();
        try {
            new JsonToJavaClassConversion().convertJsonToJavaClass(inputJson.toURI().toURL(), outputPojoDirectory, packageName, inputJson.getName().replace(".json", ""));
        } catch (IOException e) {
            System.out.println("Encountered issue while converting to pojo: " + e.getMessage());
            e.printStackTrace();
        }
    }


    public void convertJsonToJavaClass(URL inputJsonUrl, File outputJavaClassDirectory, String packageName, String javaClassName) throws IOException {
        JCodeModel jcodeModel = new JCodeModel();

        GenerationConfig config = new DefaultGenerationConfig() {
            @Override
            public boolean isGenerateBuilders() {
                return true;
            }

            @Override
            public SourceType getSourceType() {
                return SourceType.JSON;
            }
        };

        SchemaMapper mapper = new SchemaMapper(new RuleFactory(config, new Jackson2Annotator(config), new SchemaStore()), new SchemaGenerator());
        mapper.generate(jcodeModel, javaClassName, packageName, inputJsonUrl);

        jcodeModel.build(outputJavaClassDirectory);
    }

}