利用jackson-dataformat-csv读写csv文件

csv是comma-separated values的缩写，这类文件在日常项目中有时比较常见。sql工具一般具有将数据库数据导入、导出csv格式。

利用jackson-dataformat-csv读写csv文件，重点在与两个类：CsvMapper和CsvSchema。其中CsvMapper和我们利用jackson转换son数据用的那个类相似，承担java对象和csv格式字符串之间的转换。CsvSchema则定义了读写csv数据的那些属性名。

        CsvMapper csvMapper = new CsvMapper();
        CsvSchema csvSchema = csvMapper.schemaFor(CostDetail.class);

        CsvSchema csvSchema = csvMapper.schemaFor(CostDetail.class).withHeader();

        CostDetail costDetail = new CostDetail();
        costDetail.setAmount(BigDecimal.valueOf(12.55D));
        costDetail.setApplyId(11L);
        costDetail.setCostCenterId(66L);
        costDetail.setCreatedTime(new Date());
        costDetail.setStatus(1L);
        costDetail.setTypeId(77L);
        costDetail.setTypeName("v");
        costDetail.setUserId(88L);
        CsvMapper csvMapper = new CsvMapper();
        CsvSchema csvSchema = csvMapper.schemaFor(CostDetail.class).withHeader();
        System.out.println(csvSchema);
        csvSchema.forEach(t -> System.out.println(t.getName()));
        try (SequenceWriter writer = csvMapper.writer(csvSchema).writeValues(new File("csv.csv"));) {
            writer.write(costDetail);
            // ---
        } catch (Exception e) {
            throw e;
        }

        

    

amount,applyId,costCenterId,createdTime,status,typeId,typeName,userId
12.55,11,66,1456649517855,1,77,v,88

那我们看下如何读取数据的：

文件内容为：

amount,applyId,costCenterId,createdTime,status,typeId,typeName,userId
12.55,11,66,1456646940091,1,77,v,88
112.55,111,616,1456646940091,1,77,v,84

 CsvSchema schema = CsvSchema.emptySchema().withHeader();

        System.out.println("read from file");
        try (InputStream inputStream = JacksonDataformatCsvFile.class.getClassLoader().getResourceAsStream("data.csv");) {

            MappingIterator<CostDetail> values = csvMapper.readerFor(CostDetail.class).with(schema).readValues(inputStream);
            values.forEachRemaining(System.out::println);
        } catch (Exception e) {
            // TODO: handle exception
        }

 CsvSchema schema = CsvSchema.emptySchema().withHeader();

你是否注意到日期到格式化是不是太。。。

我们可以配置：

        csvMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));

amount,applyId,costCenterId,createdTime,status,typeId,typeName,userId
12.55,11,66,"2016-02-28 17:08:36",1,77,v,88

利用jackson-dataformat-csv读写csv文件

原文：http://blog.csdn.net/doctor_who2004/article/details/50760622