opencsv4.0 读写

个人最推荐方式：使用注解

     List beans = new CsvToBeanBuilder(FileReader("yourfile.csv"))
       .withType(Visitors.class).build().parse();

如：Visitors   

 

@CsvBindByName(column = "Id", required = true)  //是否可以为null 否
private int Id;

 
@CsvBindByName(column = "姓名", required = false) //是否可用为null  是
private String userName;

@CsvBindByName(column = "date", required = false)
@CsvDate("yyyy-MM-dd HH:mm:ss")         //自动转换日期格式
private Date  date;

  优势：

   自动完成转换

                   支持但不限于 String int double  date 等类型

 openCSV是一款简单的用于解析CSV文件的java类库，它封装了CSV格式文件的读写操作，可将文件与java对象进行自动映射，自定义分隔符，使用转义符等。

在使用时有几点需要注意下：

        1、       生成的csv文件用EXCEL打开时，总是产生乱码，但是用NOTEPAD++打开时，显示正常。这是因为导出的文件是UTF-8不含BOM格式编码的，为了要让EXCEL正确的显示，需要手动的给将要输出的内容加上BOM标识。

        2、       可通过@ CsvBindByName和@ CsvBindByPosition来CSV文件字段与对象属性进行映射。@ CsvBindByName是根据表头的名称来映射；@CsvBindByPosition是根据文件中字段的位置来映射。当2个注解一起使用时则基于位置的方式有效。因此如果写文件时即想指定顺序又想加表头的话需手动写表头。

        3、       在读CSV文件时需要注意BOM字符，因为在写文件时为了能在Excel里打开增加了UTF-8 BOM标识，读文件时第一列会读不出来。这种情况的解决方法是使用apache commons io提供的BOMInputStream。

        代码示例如下

public class Person {

    private String name;

    private int age;

    private int sex;

    private String phone;

    private String address;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public int getSex() {
        return sex;
    }

    public void setSex(int sex) {
        this.sex = sex;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String toString() {
        return ":"+name + ";" + age + ";" + sex + ";" + phone + ";" + address;
    }
}

public class WriteCSV {

    public void writeCSV2(List dataList, String finalPath) {
        try {
            Writer writer = new FileWriter(finalPath);
            // 手动加上BOM标识
            writer.write(new String(new byte[] { (byte) 0xEF, (byte) 0xBB, (byte) 0xBF }));

            // 设置显示的顺序
            String[] columnMapping = { "name", "age", "sex", "phone", "address" };
            ColumnPositionMappingStrategy mapper =
                    new ColumnPositionMappingStrategy();
            mapper.setType(Person.class);
            mapper.setColumnMapping(columnMapping);

            // 写表头
            CSVWriter csvWriter = new CSVWriter(writer, CSVWriter.DEFAULT_SEPARATOR,
                    CSVWriter.NO_QUOTE_CHARACTER);
            String[] header = { "姓名", "年龄", "性别", "手机", "住址" };
            csvWriter.writeNext(header);

            StatefulBeanToCsv beanToCsv = new StatefulBeanToCsvBuilder(writer)
                    .withMappingStrategy(mapper)
                    .withQuotechar(CSVWriter.NO_QUOTE_CHARACTER)
                    .withSeparator(CSVWriter.DEFAULT_SEPARATOR)
                    .withEscapechar('\\').build();
            beanToCsv.write(dataList);
            csvWriter.close();
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (CsvDataTypeMismatchException e) {
            e.printStackTrace();
        } catch (CsvRequiredFieldEmptyException e) {
            e.printStackTrace();
        }
        System.out.println(finalPath + "数据导出成功");
    }

    public void readCSV2(String finalPath) {
        try {
            // 使用BOMInputStream自动去除UTF-8中的BOM
            Reader reader = new InputStreamReader(new BOMInputStream(
                    new FileInputStream(finalPath)), "utf-8");
            CSVReader csvReader = new CSVReader(reader, CSVWriter.DEFAULT_SEPARATOR,
                    CSVWriter.NO_QUOTE_CHARACTER);

            // 列名的映射
            HeaderColumnNameTranslateMappingStrategy strategy =
                    new HeaderColumnNameTranslateMappingStrategy();
            strategy.setType(Person.class);
            Map columnMapping = new HashMap();
            columnMapping.put("姓名", "name");
            columnMapping.put("年龄", "age");
            columnMapping.put("性别", "sex");
            columnMapping.put("手机", "phone");
            columnMapping.put("住址", "address");
            strategy.setColumnMapping(columnMapping);

            CsvToBean csvToBean = new CsvToBean();

            List list = csvToBean.parse(strategy, csvReader);

            for (Person p : list) {
                System.out.println(p.toString());
            }
            csvReader.close();
            reader.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        List dataList = new ArrayList();
        Person person1 = new Person();
        person1.setName("張三");
        person1.setSex(1);
        person1.setAge(55);
        person1.setPhone("13911111111");
        person1.setAddress("北京海淀区");
        dataList.add(person1);
        Person person2 = new Person();
        person2.setName("小美");
        person2.setSex(0);
        person2.setAge(20);
        person2.setPhone("13911112222");
        person2.setAddress("北京西城区");
        dataList.add(person2);
        Person person3 = new Person();
        person3.setName("小明");
        person3.setSex(1);
        person3.setAge(25);
        person3.setPhone("13933333333");
        person3.setAddress("北京海淀区");
        dataList.add(person3);

        WriteCSV writer = new WriteCSV();
        String finalPath2 = "D:/bbb.csv";
        writer.writeCSV2(dataList, finalPath2);
        writer.readCSV2(finalPath2);
    }
}