使用 Mockito/PowerMockito 伪造方法参数

Question

public class FakeExcelSheet implements Sheet
{
     private final Map<Integer, FakeExcelRow> fakeSheet = new HashMap<Integer, FakeExcelRow>();

     @Override
     public Row createRow(int rowNum)
     {
          Row row = new FakeExcelRow(rowNum, fakeSheet);
          fakeSheet.put(rowNum, (FakeExcelRow)row);
          return row;
     }

     @Override
     public Row getRow(int rowNum)
     {
          if (fakeSheet.get(rowNum) != null)
          {
               return fakeSheet.get(rowNum);
          }
          else
          {
               return createRow(rowNum);
          }

     }

     /**Other unimplemented methods of Apache POI class Sheet**/ 
}

public class FakeExcelRow implements Row
{
    private int rowNum;
    private Map<Integer, FakeExcelRow> sheet;
    private List<Object> cellList = new LinkedList<Object>();

    public FakeExcelRow(int rowNum , Map<Integer,FakeExcelRow> sheet)
    {
          this.rowNum = rowNum;
          this.sheet = sheet;
    }

    @Override
    public Cell createCell(int colNum)
    {
         return new FakeExcelCell(colNum, rowNum, sheet);
    }

    /**Other unimplemented methods of Apache POI class Row**/
}

public class FakeExcelCell implements Cell
{
      private int colNum;
      private int rowNum;
      private Map<Integer, FakeExcelRow> sheet;

      public FakeExcelCell(int colNum, int rowNum, Map<Integer, FakeExcelRow> sheet)
      {
          this.colNum = colNum;
          this.rowNum = rowNum;
          this.sheet = sheet;
      }

      public void setCellValue(String value)
      {
           if(sheet != null)
           {
                FakeExcelRow fakeExcelRow = sheet.get(rowNum);
                List<Object> cellList = fakeExcelRow.getCellList();
                cellList.add(value);
           }
      }

      /**Other unimplemented methods of Apache POI class Cell**/
}

我必须像这样测试使用 ExcelWriter 类的受保护方法 writeToCell 的类服务：

public class ServiceImpl
{
     ........
     .
     .
     private ExcelWriter excelWriter;
     private Sheet sheet;
     private void handleRequest()
     {

           while("Till there are more rows")
           {
           excelWriter.writeDetailsForCategory(List<String> listOfItems)
           }
     }
 }

ExcelWriter 类是这样设计的：

public class ExcelWriter()
{
     protected Sheet sheet;
     public void writeDetailsForCategory(List<String> listOfItems)
     {
           for(String item : listOfItems)
           {
                 writeToCell(rowNum, columnNum, value, sheet);
                 columnNum++;
           }
     }
}

writeToCell() 方法设计有受保护的访问修饰符：

protected void writeCell(int rowNum, int colNum, String value, Sheet sheet)
{

    if (value == null)
    {
        return;
    }

    Row row = sheet.getRow(rowNum);

    if (row == null)
    {
        row = sheet.createRow(rowNum);
    }

    Cell cell = row.createCell(colNum);
    cell.setCellValue(value);

}

我必须对使用 ExcelWriter 的 writeDetailsForCategory 的 ServiceImpl 类的 handleRequest 方法进行单元测试，该方法使用受保护的方法 writeToCell。我已经在writeToCell 方法中传递了FakeExcelSheet。在此之后我将断言Map <Object, FakeExcelRow> 的值。我应该如何在protectedwriteToCell方法中传入fakeExcelSheet参数？我的限制是我只能使用 Mockito 或 PowerMockito。

Answer 1

从我的other answer 开始，您可以将特定的ExcelWriter 替换为StringGridWriter，它会写入给定的StringGrid。它不知道也不关心它是 excel。

public final class StringGridWriter() {
     private final StringGrid grid;

     public StringGridWriter(StringGrid grid) {
        this.grid = grid;
     }

     public void writeDetailsForCategory(List<String> listOfItems) {
           for(String item : listOfItems) {
                 grid.writeToCell(rowNum, columnNum, value);
                 columnNum++;
           }
     }
}

在服务中的使用：

public class ServiceImpl {
     ........
     .
     .
     private final StringGridWriter gridWriter;

     public ServiceImpl(StringGridWriter gridWriter) {
         this.gridWriter = gridWriter;
     }

     private void handleRequest() {    
           while("Till there are more rows"){
             gridWriter.writeDetailsForCategory(List<String> listOfItems)
           }
     }
 }

这就是您分配给它以使用它的方式：

Sheet theApacheSheet = ...;

StringGrid grid = new ApacheSheetStringGrid(theApacheSheet);

StringGridWriter writer = new StringGridWriter(grid);

ServiceImpl service = new ServiceImpl(writer);

ApacheSheetStringGrid 的位置与我的其他答案相同。所以现在，即使ServiceImpl 也不知道这是在使用 excel。这种依赖注入实际上是Dependency Inversion Principle。

看看我如何快速摆脱复杂的 excel 界面并将其归结为一个抽象，一个功能子集，这只是我的客户想要的界面 (Interface Segregation Principle)，这使得它既易于测试，并且易于替换为其他实现。通过不抽象，您将代码与 apache excel 实现紧密耦合。