通过json模式将map转换为json字符串 [英] Convert map to json string by json schema

问题描述

是否可以通过json模式将地图转换为json字符串?我需要通过json模式执行此操作，因为我不知道映射中的对象是字符串还是数字.例如，我的csv如下所示:

Is there a way to convert the map to json string by json schema? I need to do that by json schema because I don't know if the object in the map is a string or a number. For example, I have csv that look like this:

name, year
1   , 1

我需要将其转换为json字符串"{'name': '1', 'year': 1}"，仅通过json模式，我就可以知道1是字符串(在名称中)还是数字(在年份中).

I need to convert it to json string "{'name': '1', 'year': 1}" and I can know if 1 is a string (in a case of the name) or number (in a case of the year) only by json schema.

推荐答案

您可以使用Jackson尝试类似的方法:

You could try something like this using Jackson:

您唯一需要自己实现的方法是将CsvSchema.json转换为包含列名和列类型的Map的第二种方法.

The only thing you need to implement by yourself is the second method to convert your CsvSchema.json to a Map containing the column name and the column type.

     public String generateJsonFromCSV() throws IOException {
        File csvFile = new File("path/to/csv/mycsv.csv");
        File schemaJson = new File("path/to/json/schema.json");
        Map<String, CsvSchema.ColumnType> map = getSchemaMapFromJson(schemaJson);
        CsvSchema.Builder schemaBuilder = new CsvSchema.Builder();
        map.forEach(schemaBuilder::addColumn);
        CsvSchema schema = schemaBuilder.build();
        CsvMapper csvMapper = new CsvMapper();
        MappingIterator<Map<?, ?>> mappingIterator = csvMapper.readerFor(Map.class).with(schema).readValues(csvFile);
        String json = new ObjectMapper().writeValueAsString(mappingIterator.readAll());
        return json;
    }

    //Convert your JsonSchema to Map<String,CsvSchema.ColumnType>
    private Map<String, CsvSchema.ColumnType> getSchemaMapFromJson(File file) {
        return new HashMap<>();
    }

依赖性:

<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-csv</artifactId>
    <version>${jackson.version}</version>
</dependency>

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