CSV和集合对象基于Annotation操作封装

随着项目上线，暂时处于闲置状态，所以趁闲带着团队对在这一年项目中做的比较好的组件，工具和实践总结和抽取出来，在我后续的随笔中将会陆续发布出来。今天主要是一个简单的maven小组件，对opencsv基于Annotation简单的封装，使得我们可以轻易的将CSV文件转化为List对像和把List对像导出为CSV文件。

项目托管地址于github https://github.com/greengerong/opencsv-utils。

对于代码就不用多说了，简单看看如何使用。

Object

package opencsv.utils;

public class Person {

private int id;

@Csv("person name")

private String name;

@Ignore

private int age;

public Person(int id, String name, int age) {

this.id = id;

this.name = name;

this.age = age;

}

public Person() {

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

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;

}

}

Mapping会自动将没有ignore的字段作为CSV的映射属性名作为CSV列头，如果针对特殊列则可以标记@CSV解决。

1： 读取CSV:

(1) 基于Annotation映射方式

@Test

public void shouldGetPersonFromCSV() throws Exception {

StringReader reader = new StringReader("id,person name\n1,name1\n2,name2\n");

List<Person> personList = personCsvMapper

.withMapping("id", "id")

.withMapping("person name", "name")

.fromCsv(reader);

assertThat(personList.size(), is(2));

final Person first = personList.get(0);

assertThat(first.getId(), is(1));

assertThat(first.getName(), is("name1"));

final Person second = personList.get(1);

assertThat(second.getId(), is(2));

assertThat(second.getName(), is("name2"));

}

(2) 自定义映射方式

@Test

public void shouldToCsv() throws Exception {

personCsvMapper.withMapping(new CsvColumnMapping(Person.class));

final ArrayList<Person> list = new ArrayList<Person>();

list.add(new Person(1, "name1", 20));

list.add(new Person(2, "name2", 30));

final StringWriter writer = new StringWriter();

personCsvMapper.toCsv(writer, list);

final String text = writer.toString();

assertThat(text, is("id,person name\n1,name1\n2,name2\n"));

}

2: CSV输出

@Test

public void shouldGetPersonFromCsv() throws Exception {

StringReader reader = new StringReader("id,person name\n1,name1\n2,name2\n");

List<Person> personList = new CsvMapper<Person>(Person.class)

.withMapping(new CsvColumnMapping(Person.class))

.fromCsv(reader);

assertThat(personList.size(), is(2));

final Person first = personList.get(0);

assertThat(first.getId(), is(1));

assertThat(first.getName(), is("name1"));

final Person second = personList.get(1);

assertThat(second.getId(), is(2));

assertThat(second.getName(), is("name2"));

}

最后在累赘下托管地址:https://github.com/greengerong/opencsv-utils。其他的相比不用再说了。