Question

我正在使用Apache PdfBox库，并且注意到几乎所有东西都抛出IOException，考虑到大多数IOException实际上应该是非法的状态异常，这很烦人，但是apache希望客户端能够处理它他们强迫他们作为检查的例外。反正...

我的问题是，如何将IOException包装到扩展RuntimeException的自定义异常中，从而使API易于处理？

示例：

private final PDDocument document;
private final PDPage page;
private final PDFont font;

public PdfBoxWrapper(PDDocument document, PDPage page, PDFont font)
{
    this.document = document;
    this.page = page;
    this.font = Objects.isNull(font) ? PDType1Font.HELVETICA : font;

    this.document.addPage(this.page);

    try 
    {
        this.canvas = new PDPageContentStream(this.document, this.page);
    } 

    catch (IOException exception) {
        logger.error(exception.getMessage());
    }
}

注意如何在尝试捕获中包装PDPageContentStream。如何将IOException从PdfBox包装为PdfBoxIllegalStateException？

如下所示：

public class PdfBoxIllegalStateException extends RuntimeException
{
    public PdfBoxIllegalStateException(String message)
    {
        super(message);
    }

    public PdfBoxIllegalStateException(String message, Throwable cause)
    {
        super(message, cause);
    }
}

Answer 1

您可以抓住IOException，然后将其包裹在PdfBoxIllegalStateException中，然后再次扔掉。

private final PDDocument document;
private final PDPage page;
private final PDFont font;

public PdfBoxWrapper(PDDocument document, PDPage page, PDFont font)
{
    this.document = document;
    this.page = page;
    this.font = Objects.isNull(font) ? PDType1Font.HELVETICA : font;

    this.document.addPage(this.page);

    try 
    {
        this.canvas = new PDPageContentStream(this.document, this.page);
    } 

    catch (IOException exception) {
        logger.error(exception.getMessage());
        throw new PdfBoxIllegalStateException(exception);
    }
}

如何将IOException吞入自定义运行时异常Java 8

1 个答案: