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Java

Posted by Mridul Gupta
Mridul Gupta
2,144 Points

Import 2 strings and one object from a file??

Referring to my previous question over here https://teamtreehouse.com/community/map-inside-a-map-how-to-load-and-store-values-from-files-using-serialisation

I understood how to use export to file method in my project but now i am facing problem in import because i have 2 strings and 1 object in the file. In the video Craig told to split the string, but here it is generating error because if i split, it doesn't remain an object.

public void importFrom() {
        File myFile = new File(mName + ".ser");
        try (
                FileInputStream fis = new FileInputStream(myFile);
                BufferedReader reader = new BufferedReader(new InputStreamReader(fis));
        ) {
            String line;
            while((line = reader.readLine()) != null) {
                String[] args = line.split("\\|");
                insertToMap(args[0],args[1],args[2]);                
            }
        } catch(IOException ioe) {
            System.out.printf("Problems loading %s %n", myFile);
            ioe.printStackTrace();
        }
    }

I am also including my export method i implemented for reference.

public void exportTo() throws IOException {
        File myFile = new File(mName + ".ser");
        if (!myFile.exists()) {
            myFile.createNewFile();
        }
        try (
                FileOutputStream fos = new FileOutputStream(myFile);
                PrintWriter writer = new PrintWriter(fos);
        ) {
            for (Map.Entry<String, Map<String, List<Investment>>> entry1 : mInvestmentMap.entrySet()) {
                Map<String, List<Investment>> innerMap = entry1.getValue();
                for (Map.Entry<String, List<Investment>> entry2 : innerMap.entrySet()) {
                    List<Investment> innerList = entry2.getValue();
                    for (Investment myObject : innerList) {
                        writer.printf("%s|%s|%s%n",
                                entry1.getKey(),
                                entry2.getKey(),
                                myObject.toString());
                    }
                }
            }
        } catch (IOException ioe) {
            System.out.printf("Problem saving %s.ser %n", mName);
            ioe.printStackTrace();
        }
    }

My InsertToMap method

public void insertToMap(String a, String b, Investment inv) {

        if (!mInvestmentMap.containsKey(a)) {
            List<Investment> list = new ArrayList<>();
            list.add(inv);
            Map<String, List<Investment>> innerMap = new HashMap<>();
            innerMap.put(b, list);
            mInvestmentMap.put(a, innerMap);
        } else if (!mInvestmentMap.get(a).containsKey(b)) {
            List<Investment> list = new ArrayList<>();
            list.add(inv);
            mInvestmentMap.get(a).put(b, list);
        } else {
            mInvestmentMap.get(a).get(b).add(inv);
        }

    }