JAva簡易excelエクスポートインポートツール(パッケージPOI)

githubアドレス
Octopus Octopusは簡単なjava excelインポートエクスポートツールである.
EXcelのインポート方法
次はexcelファイルのsheetのデータで、4人の学生情報があります.
studentId
name
sex
inTime
score
20134123
John
M
2013-9-1
89
20124524
Joyce
F
20123-8-31
79
20156243
P
2015-5-15
94
20116522
Nemo
F
2011-2-26
excelから読み出す学生情報を保存する学生クラス.

//lombok annotations
@Getter
@Setter
@NoArgsConstructor
@ToString
public class Student {

    @ModelLineNumber
    private int lineNum;

    @ModelProperty(value = "id",blankable = false)
    private String studentId;

    @ModelProperty(value = "name",defaultValue = "anonymous")
    private String name;

    @ModelProperty(value = "sex",wrongMsg = "sex must be M or F",pattern = "^M|F$")
    private String sex;

    @ModelProperty(value = "admission",wrongMsg = "admission must be a date")
    private LocalDate inTime;

    @ModelProperty(value = "score",wrongMsg = "score must be numeric",defaultValue = "100")
    private Double score;

}

コードでexcelを読み込み、学生情報を出力します.

InputStream is = getClass().getResourceAsStream("/test.xlsx");
Workbook workbook = WorkbookFactory.create(is);
Sheet sheet = workbook.getSheetAt(0);

//read students with ReusableSheetReader
SheetReader> students = new ReusableSheetReader<>(sheet,1,0,Student.class);

//print students information
for (ModelEntity student:students) {
    System.out.println(student.toString());
}

学生情報の出力

SimpleModelEntity(entity=Student(lineNum=2, studentId=20134123, name=John, sex=M, inTime=2013-09-01, score=89.0, gradeAndClazz=null), exceptions=[])
SimpleModelEntity(entity=Student(lineNum=3, studentId=20124524, name=Joyce, sex=F, inTime=null, score=79.0, gradeAndClazz=null), exceptions=[cn.chenhuanming.octopus.exception.DataFormatException: in cell (3,4) ,20123-8-31 can not be formatted to class java.time.LocalDate])
SimpleModelEntity(entity=Student(lineNum=4, studentId=20156243, name=anonymous, sex=null, inTime=2015-05-15, score=94.0, gradeAndClazz=null), exceptions=[cn.chenhuanming.octopus.exception.PatternNotMatchException: P and ^M|F$ don't match!])
SimpleModelEntity(entity=Student(lineNum=5, studentId=20116522, name=Nemo, sex=F, inTime=2011-02-26, score=100.0, gradeAndClazz=null), exceptions=[])

ModelEntityにより、より多くの異常情報、例えば@ModelPropertyの構成情報と発生する異常を取得することができる.
完全なテスト例:src/test/cn/chenhuanming/octopus/core/SheetReaderTestEXcelのエクスポート方法
導出特性を説明するために、Studentクラスに学年とクラスを表す属性GradeAndClazzを追加した.以下は最終的なStudentクラスであり、導出に用いることができる.

@Getter
@Setter
@NoArgsConstructor
@ToString
public class Student {

    @ModelLineNumber
    private int lineNum;

    @ModelProperty(value = "id",blankable = false)
    private String studentId;

    @ModelProperty(value = "name",defaultValue = "anonymous")
    private String name;

    @ModelProperty(value = "sex",wrongMsg = "sex must be M or F",pattern = "^M|F$")
    private String sex;

    //jackson annotation to format output
    @JsonFormat(pattern = "yyyy-MM-dd")
    @ModelProperty(value = "admission",wrongMsg = "admission must be a date")
    private LocalDate inTime;

    @ModelProperty(value = "score",wrongMsg = "score must be numeric",defaultValue = "100")
    private Double score;

    @ModelIgnore
    private GradeAndClazz gradeAndClazz;

    public Student(String studentId, String name, String sex, LocalDate inTime, Double score,GradeAndClazz gradeAndClazz) {
        this.studentId = studentId;
        this.name = name;
        this.sex = sex;
        this.inTime = inTime;
        this.score = score;
        this.gradeAndClazz = gradeAndClazz;
    }
}

GradeAndClazz類で、学年とクラスの2つの情報しかありません.

@Getter
@Setter
@AllArgsConstructor
public class GradeAndClazz{
    private String grade;
    private String clazz;
}

エクスポートされたプロパティとプロパティの説明をヘッダーとして構成するにはxmlが必要です.

コードによる学生情報のエクスポート

//prepare workbook and stuednts objects
Workbook workbook = new XSSFWorkbook();
String rootPath = this.getClass().getClassLoader().getResource("").getPath();
FileOutputStream os = new FileOutputStream(rootPath+"/export.xlsx");
GradeAndClazz gradeAndClazz = new GradeAndClazz("2014","R6");
Student student1 = new Student("201223","John","M", LocalDate.now(),98.00,gradeAndClazz);
Student student2 = new Student("204354","Tony","M", LocalDate.now(),87.00,gradeAndClazz);
Student student3 = new Student("202432","Joyce","F", LocalDate.now(),90.00,gradeAndClazz);

//write excel with OneSheetExcelWriter
ExcelWriter studentExcelWriter = new OneSheetExcelWriter<>(getClass().getClassLoader().getResourceAsStream("studentExport.xml"));

studentExcelWriter.write(workbook,Arrays.asList(student1,student2,student3));
workbook.write(os);

結果のエクスポート

                                          |    class info      |
id        name    M     admission   score |---------|----------|
                                          |  grade  |   class  |
---------------------------------------------------------------|
201223    John    M     2017-07-06  98.0  |  2014   |   R6     |
204354    Tony    M     2017-07-06  87.0  |  2014   |   R6     |
202432    Joyce   F     2017-07-06  90.0  |  2014   |   R6     |

gradeAndClazzプロパティでは、@JsonFormatでマークされているため、出力日がフォーマットされます.実際にはOctopusがjacksonを呼び出してjsonをフォーマットしてexcelに書き込む.
詳細例src/test/cn/chenhuanming/octopus/core/OneSheetExcelWriterTest