Gson programs

DataModel

import java.util.ArrayList;
import java.util.List;


public class DataModel {

    private String title = "GsonDemo";
    private int length = 1;
    private float temperature = 37.5f;
    private List<String> items = new ArrayList<String>() {
        {
            add("item1");
            add("item2");
            add("item3");
        }
    };

    @Override
    public String toString() {
        return "title=" + this.title + "\n" + "length=" + this.length + "\n" + "temperature=" + this.temperature + "items=" + this.items.toString();
    }
}

DataModelComplex

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import java.util.ArrayList;


public class DataModelComplex {
    private String status;
    private ArrayList<Results> results;

    /**
     * @return the status
     */
    public String getStatus() {
        return status;
    }

    /**
     * @param status the status to set
     */
    public void setStatus(String status) {
        this.status = status;
    }

    /**
     * @return the results
     */
    public ArrayList<Results> getResults() {
        return results;
    }

    /**
     * @param results the results to set
     */
    public void setResults(ArrayList<Results> results) {
        this.results = results;
    }
}

Geometry

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public class Geometry {
    private Location location;

    /**
     * @return the location
     */
    public Location getLocation() {
        return location;
    }

    /**
     * @param location the location to set
     */
    public void setLocation(Location location) {
        this.location = location;
    }
    
}

GsonBasicJsonRead

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import com.google.gson.Gson;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStreamReader;
import pojo.DataModel;


public class GsonBasicJsonRead {

    public GsonBasicJsonRead() throws FileNotFoundException {
        FileInputStream fileInputStream = new FileInputStream(new File("input.json"));
        BufferedReader reader = new BufferedReader(new InputStreamReader(fileInputStream));
        Gson gson = new Gson();
        DataModel dataModel = gson.fromJson(reader, DataModel.class);
        System.out.println("\n--------------------------------------\n");
        System.out.println(dataModel.toString());
        System.out.println("--------------------------------------");
    }
}

GsonBasicJsonWrite

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import com.google.gson.Gson;
import java.io.FileWriter;
import java.io.IOException;
import pojo.DataModel;
import pojo.DataModelComplex;


public class GsonBasicJsonWrite {

    public GsonBasicJsonWrite() throws IOException {
        Gson gson =new Gson();
        
        String json=gson.toJson(DataModel.class);

        FileWriter fileWriter = new FileWriter("output.json");
        fileWriter.write(json);
        fileWriter.close();
        
    }
    
}

GsonComplexJsonRead

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import com.google.gson.Gson;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStreamReader;
import pojo.DataModelComplex;


public class GsonComplexJsonRead {

    public GsonComplexJsonRead() throws FileNotFoundException{
        BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("input_complex.json")));
        Gson gson = new Gson();
        DataModelComplex dataModel=gson.fromJson(reader,DataModelComplex.class);
        
        System.out.println("status : "+dataModel.getStatus());
        int results = dataModel.getResults().size();
        for(int i=0;i<results;i++){
            System.out.println("\n---------------Result "+i+"-----------------\n");
            System.out.println("formatted_address : "+ dataModel.getResults().get(i).getFormatted_address());
            System.out.println("types : "+ dataModel.getResults().get(i).getTypes().get(i));
            System.out.println("location : "+ dataModel.getResults().get(i).getGeometry().getLocation().getLat()+","+dataModel.getResults().get(i).getGeometry().getLocation().getLon());
            System.out.println("-------------------------------------------\n");
        }
    }
    
    
}

GsonComplexJsonWrite

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import com.google.gson.Gson;
import java.io.FileWriter;
import java.io.IOException;
import pojo.DataModelComplex;


public class GsonComplexJsonWrite {

    public GsonComplexJsonWrite() throws IOException {
        Gson gson =new Gson();
        String json=gson.toJson(new DataModelComplex());

        FileWriter fileWriter = new FileWriter("output.json");
        fileWriter.write(json);
        fileWriter.close();
    }
    
    
}

Location

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public class Location {
    private double lat;
    private double lng;

    /**
     * @return the lat
     */
    public double getLat() {
        return lat;
    }

    /**
     * @param lat the lat to set
     */
    public void setLat(double lat) {
        this.lat = lat;
    }

    /**
     * @return the lon
     */
    public double getLon() {
        return lng;
    }

    /**
     * @param lon the lon to set
     */
    public void setLon(double lon) {
        this.lng = lon;
    }
    
}

MainClass

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import java.util.Scanner;


public class GsonDemo {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws Exception {
        // TODO code application logic here
        Scanner sc=new Scanner(System.in);
        switch(sc.nextInt()){
            case 1:
                new GsonBasicJsonRead();
                break;
            case 2:
                new GsonBasicJsonWrite();
                break;
            case 3:
                new GsonComplexJsonRead();
                break;
            case 4:
                new GsonComplexJsonWrite();
                break;
            default:break;
        }
    }
}

Results

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import java.util.ArrayList;


public class Results {
    private String formatted_address;
    private ArrayList<String> types;
    private Geometry geometry;

    /**
     * @return the formatted_address
     */
    public String getFormatted_address() {
        return formatted_address;
    }

    /**
     * @param formatted_address the formatted_address to set
     */
    public void setFormatted_address(String formatted_address) {
        this.formatted_address = formatted_address;
    }

    /**
     * @return the types
     */
    public ArrayList<String> getTypes() {
        return types;
    }

    /**
     * @param types the types to set
     */
    public void setTypes(ArrayList<String> types) {
        this.types = types;
    }

    /**
     * @return the geometry
     */
    public Geometry getGeometry() {
        return geometry;
    }

    /**
     * @param geometry the geometry to set
     */
    public void setGeometry(Geometry geometry) {
        this.geometry = geometry;
    }

}

This has a complete list of programs for using Gson to read/write basic/complex json.