Question

目标： - 我必须将3个json文件合并到1个json文件中。我需要在从输出文件中删除最后一个字符后将文本附加到输出文件中。

注意： - 我这样做是为了将3个json文件合并到1个json文件中。我想将文本附加到输出文件中。这个代码附加了文本，但是不要删除最后一个}。任何人都可以帮我提供代码。提前感谢您，并提前度过美好的一天。

我有json对象的名称，电子邮件，lat，lon，date的记录。这个字段在不同的json文件中。我已将它们合并为1个json文件。这个工作已经完成。

预期输出： - 当我追加下一条记录时，我希望json文件看起来像

{Record:[{"name1","val","date1","val","lat1","val"..}],[{"name2","val","date2","val","lat2","val"...}]}

输出成绩： -

{Record:[{"name1","val","date1","val","lat1","val"..}],{Record:[{"name2","val","date2","val","lat2","val"...}]}

代码： -

 static class CopyFileContent {

    public static void main(String[] args) {

        String root = Environment.getExternalStorageDirectory().toString(); //get access to directory path
        File myDir = new File(root + "/GeoPark");//create folder in internal storage
        myDir.mkdirs();// make directory
        File destFile = new File(myDir, FILENAME11);//making a new file in the folder
    /* Source file, from which content will be copied */
        File sourceFile1 = new File(myDir, FILENAME12);
        File sourceFile2 = new File(myDir, FILENAME13);
        File sourceFile3 = new File(myDir, FILENAME14);

    /* destination file, where the content to be pasted */
        // File destFile = new File(FILENAME);

    /* if file not exist then create one */
        if (!destFile.exists()) {
            try {
                destFile.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        InputStream input1 = null;
        InputStream input2 = null;
        InputStream input3 = null;
        OutputStream output = null;
        InputStream input4 = null;

        try {

            /* FileInputStream to read streams */
            input1 = new FileInputStream(sourceFile1);
            input2 = new FileInputStream(sourceFile2);
            input3 = new FileInputStream(sourceFile3);

        /* FileOutputStream to write streams */
            output = new FileOutputStream(destFile, true);

            byte[] buf = new byte[1024];
            int bytesRead;
            output.write("{Record:[{".getBytes());
            while ((bytesRead = input1.read(buf)) > 0) {
                output.write(buf, 1, bytesRead);

                RandomAccessFile f = new RandomAccessFile(destFile, "rw");
                long length = f.length() - 2;
                f.setLength(length);
                length = f.length();
                f.close();
                output.write(",".getBytes());

            }

            while ((bytesRead = input2.read(buf)) > 0) {
                output.write(buf, 1, bytesRead);
                RandomAccessFile f = new RandomAccessFile(destFile, "rw");
                long length = f.length() - 2;
                f.setLength(length);
                length = f.length();
                f.close();
                output.write(",".getBytes());

            }

            while ((bytesRead = input3.read(buf)) > 0) {
                output.write(buf, 1, bytesRead);
                RandomAccessFile f = new RandomAccessFile(destFile, "rw");
                long length = f.length() - 2;
                f.setLength(length);
                length = f.length();
                f.close();
                output.write(",".getBytes());
                output.write(b.getBytes());
                output.write(d.getBytes());
                output.write("}]}".getBytes());
                RandomAccessFile f1=new RandomAccessFile(destFile,"rw");
                long length1= f1.length()-1;
                f1.setLength(length1);
                f1.close();

                output.write(",".getBytes());
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {

                if (null != input1) {
                    input1.close();
                }

                if (null != input2) {
                    input2.close();
                }

                if (null != input3) {
                    input3.close();
                }

                if (null != output) {
                    output.close();
                }

            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }

}

Answer 1

在某些情况下，您需要深度合并，合并具有相同名称的字段内容（就像在Windows中复制文件夹时一样）。此功能可能会有所帮助：

Git

如果你想合并它们，那么例如顶级对象有4个键（key1，Key2，Key3，Key4），我认为你必须手动执行：

/**
 * Merge "source" into "target". If fields have equal name, merge them recursively.
 * @return the merged object (target).
 */
public static JSONObject deepMerge(JSONObject source, JSONObject target) throws JSONException {
    for (String key: JSONObject.getNames(source)) {
            Object value = source.get(key);
            if (!target.has(key)) {
                // new value for "key":
                target.put(key, value);
            } else {
                // existing value for "key" - recursively deep merge:
                if (value instanceof JSONObject) {
                    JSONObject valueJson = (JSONObject)value;
                    deepMerge(valueJson, target.getJSONObject(key));
                } else {
                    target.put(key, value);
                }
            }
    }
    return target;
}


public static void main(String[] args) throws JSONException {
    JSONObject a = new JSONObject("{offer: {issue1: value1}, accept: true}");
    JSONObject b = new JSONObject("{offer: {issue2: value2}, reject: false}");
    System.out.println(a+ " + " + b+" = "+JsonUtils.deepMerge(a,b));

}

将三个json文件附加到一个json文件中

1 个答案: