用GSON解析多嵌套json

Question

I have to parse the json file into text file, Sample json file as below,

 { "link":"https://xxx.nt", "liveChannels":[ { "name":"Sony TV", "id":1004, "link":"https://xxx.nt", "decryptionTicket":"https://xxxy.nt", "viewLevel":"Too High", "programs": { "totalItems":1, "programs":[ { "name":"Live or die", "id":1000000000, "catchUp":["FUN"], "startOver":["Again"] } ] } } ] } 

I have used GSON to parse the file by creating the below java classes.

1. Channel
2. LiveChannel
3. programs
4. subprograms

Channel.java

public class channel 
{

    String link = null;
    ArrayList<liveChannels> liveChannels;

    public String getLink() {
        return link;
    }

    public void setLink(String link) {
        this.link = link;
    }

    public ArrayList<liveChannels> getliveChannels() {
        return liveChannels;
    }

    public void setliveChannels(ArrayList<liveChannels> liveChannels) {
        this.liveChannels = liveChannels;
    }

}

livechannel.java

public class liveChannels {

    String name = null;
    int id;
    String link = null;
    String decryptionTicket = null;
    String viewLevel = null;


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

    public String getName() {
        return name;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getLink() {
        return link;
    }

    public void setLink(String link) {
        this.link = link;
    }

    public String getDecryptionTicket() {
        return decryptionTicket;
    }

    public void setDecryptionTicket(String decryptionTicket) {
        this.decryptionTicket = decryptionTicket;
    }

    public String getViewLevel() {
        return viewLevel;
    }

    public void setViewLevel(String viewLevel) {
        this.viewLevel = viewLevel;
    }

}

After this how to parse the logic from program onwards.

"programs": { "totalItems":1,

program.java

public class programs {

    ArrayList<sub_programs> sub_programs;

    int totalItems;

    public int getTotalItems() {
        return totalItems;
    }

    public void setTotalItems(int totalItems) {
        this.totalItems = totalItems;
    }

    public ArrayList<sub_programs> getProgramsDetails() {
        return sub_programs;
    }

    public void setProgramsDetails(ArrayList<sub_programs> sub_programs) {
        this.sub_programs = sub_programs;
    }

}

sub_program.java

public class sub_programs {

    String name = null;
    int id;
    String catchUp = null;
    String startOver = null;


    public String getName() {
        return name;
    }

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

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getCatchUp() {
        return catchUp;
    }

    public void setCatchUp(String catchUp) {
        this.catchUp = catchUp;
    }

    public String getStartOver() {
        return startOver;
    }

    public void setStartOver(String startOver) {
        this.startOver = startOver;
    }

}

and main look like below,

    public static void main(String[] args) throws IOException 
    {

        Gson gson = new Gson();

        String contents = FileUtils.readFileToString(
                new File("C:/sample.json"), "UTF-8");

        channel channelHeader = gson.fromJson(contents, channel.class);

        System.out.println("Channel Information --->");

        System.out.println("Channel Link: " + channelHeader.getLink());

        ArrayList<liveChannels> liveChannels = channelHeader.getliveChannels();

        for (int i = 0; i < liveChannels.size(); i++) {
            System.out.println("liveChannels Detail --->");
            liveChannels liveChannelsDetail = liveChannels.get(i);
            System.out.println("Channel Name : " + liveChannelsDetail.getName());
            System.out.println("Channel ID : " + liveChannelsDetail.getId());
            System.out.println("Channel Description Ticket: " + liveChannelsDetail.getDecryptionTicket());
            System.out.println("Channel View Level : " + liveChannelsDetail.getViewLevel());
        }

    }

}

Could anyone please help to get the logic to parse the program from livechannel class onwards.

As programs is not an array list , What else would be an other way around to get the values.

Answer 1

You are missing the programs object in your liveChannels class.

public class liveChannels {

    String name = null;
    int id;
    String link = null;
    String decryptionTicket = null;
    String viewLevel = null;
    programs programs;

    public void setPrograms (programs programs) {
        this.programs = programs;
    }

    public programs getPrograms() {
        return programs;
    }

    ...
}

And then in your programs class, you will need to rename the sub_programs field to programs

public class programs {

    ArrayList<sub_programs> programs;

    ...
}

As an aside, your class naming does not follow Java standards and is considered bad practice. Your classes should be named as such:

Channel
LiveChannel
Program
SubProgram

Note that this will not affect GSON's ability to parse your documents as GSON cares more about the property name than it does the actual class name of the field.