Loading and storing local JSON files

To create an entity that can be saved in a JSON file format

    Public Crime (Jsonobject json) throws jsonexception{
        mId = uuid.fromstring (json.getstring (json_id));
        if (Json.has (json_title))
            Mtitle = json.getstring (json_title);
        msolved = Json.getboolean (json_solved);
        Mdate = new Date (Json.getlong (json_date));
    }

    /**
     * Converts crime object data into Jsonobject object data that can be written to the JSON file.
     * * Public
    Jsonobject Tojson () throws jsonexception{
        jsonobject json = new Jsonobject ();
        Json.put (json_id, mid.tostring ());
        Json.put (Json_title, mtitle);
        Json.put (json_solved, msolved);
        Json.put (Json_date, Mdate.gettime ());
        return JSON;
    }

Create a save and read class for a JSON file

Package com.huangfei.criminalintent;
Import Java.io.BufferedReader;
Import Java.io.FileInputStream;
Import java.io.FileNotFoundException;
Import Java.io.FileOutputStream;
Import java.io.IOException;
Import Java.io.InputStreamReader;
Import Java.io.OutputStreamWriter;
Import Java.io.Writer;

Import java.util.ArrayList;
Import Org.json.JSONArray;
Import org.json.JSONException;

Import Org.json.JSONTokener;
Import Android.content.Context;
    /** * JSON file Save and read/public class Criminalintentjsonserializer {private context mcontext;

    Private String Mfilename;
        Public Criminalintentjsonserializer (Context context, String filename) {super ();
        Mcontext = context;
    Mfilename = filename; /** * JSON file read * @throws jsonexception/public arraylist<crime> loadcrimes () throws IO
        Exception, jsonexception{arraylist<crime> crimes = new arraylist<crime> ();

        BufferedReader reader = null;
    try {        FileInputStream in = Mcontext.openfileinput (Mfilename);
            reader = new BufferedReader (new InputStreamReader (in));
            StringBuilder jsonstring = new StringBuilder ();
            String line = null;
            while (line = Reader.readline ())!= null) {jsonstring.append (line);
            } jsonarray array = (Jsonarray) New Jsontokener (Jsonstring.tostring ()). NextValue ();
            for (int i = 0; i < array.length (); i++) {Crimes.add (New Crime (Array.getjsonobject (i)));
        } catch (FileNotFoundException e) {e.printstacktrace ();
        finally {if (reader!= null) reader.close ();
    return crimes; /** * JSON File Save */public void Savecrimes (arraylist<crime> crimes) throws Jsonexception, Ioexce
        ption {Jsonarray array = new Jsonarray (); for (Crime crime:crimes) {array.put (Crime.Tojson ());

        } Writer Writer = null; try {/** * context.openfileoutput (...) method receives a file name (cannot be a directory that cannot be included/) and a file operation mode parameter, automatically attaches the incoming file name to the application sandbox file * (each applied sandbox file directory is a subdirectory of the device/data/data/directory, and the default is named by the application package).
             such as:/data/data/com.huangfei.criminalintent. * Only if the device is root, other applications and users can get the files in the sandbox at random.
             ) * After the directory path, and then creates and opens the file under the new path, waiting for the data to be written.
            * * FileOutputStream out = Mcontext.openfileoutput (Mfilename, context.mode_private);
            writer = new OutputStreamWriter (out);
        Writer.write (Array.tostring ());
        } finally{if (writer!= null) writer.close ();
 }
    }
}

the reading and saving of JSON files

        Mserializer = new Criminalintentjsonserializer (Mappcontext, FILENAME);
        try {
            mcrimes = Mserializer.loadcrimes ();
        } catch (Exception e) {
            mcrimes = new arraylist<crime> (); 
  e.printstacktrace ();
        }

public Boolean savecrimes () {
        try {
            mserializer.savecrimes (mcrimes);
            LOG.D (TAG, "crimes saved to File");
            return true;
        } catch (Exception e) {
            log.e (TAG, "Error Saving Crimes:", e);
            return false;
        } 
    }

the basic file or directory processing method provided by the context class

Method	Purpose of Use
File Getfiledir ()	Get/data/data/packagename/files Directory
FileInputStream openfileinput (String name)	Open an existing file for reading
FileOutputStream openfileoutput (String name, int mode)	Open a file for writing and create it if it does not exist
File Getdir (String name, int mode)	Gets the subdirectory of the/data/data/packagename/directory (creates it if it does not exist)
String[] FileList ()	Get a list of files in the/data/data/packagename/files directory
File Getcachedir ()	Get/data/data/packagename/cache Directory

Code address