Java 数组串联

Question

我正在尝试连接两个数组，以将标签添加到数值数组的列，并在数组的最后一行之后添加总计。我在另一个 Stack Overflow 线程 How can I concatenate two arrays in Java? 上找到了一些代码。但我收到错误

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [[Ljava.lang.Object;

这是我的代码

public void getpdf(double[][] pricelist, ArrayList<Piece> in) {
    PDDocument doc = new PDDocument();
    PDPage page = new PDPage();
    doc.addPage( page );
    try {
            PDPageContentStream contentStream =
                            new PDPageContentStream(doc, page);
            JTable table=gettable(pricelist,in);

            Object[] headercol={"Type","Asc","Ref","Commandes","Prix unitaire","Prix total"};
            Object[][] content=getTableData(table);
            Object[][] global=(Object[][]) concatenate (headercol,content);
            //drawTable(page, contentStream, 700, 75, headercol); 
            drawTable(page, contentStream, 700, 75, content); 
            contentStream.close();
            doc.save("bill.pdf" );
    }
    catch (IOException ex) {
        ex.printStackTrace();
    }

}   

public <T> T[] concatenate (T[] a, T[][] b) {
    int aLen = a.length;
    int bLen = b.length;

    @SuppressWarnings("unchecked")
    T[] c = (T[]) Array.newInstance(a.getClass().getComponentType(), aLen+bLen);
    System.arraycopy(a, 0, c, 0, aLen);
    System.arraycopy(b, 0, c, aLen, bLen);

    return c;
}

Answer 1

public <T> T[] concatenate (T[] a, T[][] b)

您不能连接两个不同类型的数组。 a 是一个 T 数组，b 是一个 T[] 数组，即它是一个T 数组的数组。