Question

需要通过iText PDF生成器在PDF中显示变量value1到value4。当我使用该值时，它显示“无法对非静态字段值1进行静态引用”。我怎么能解决这个问题？这是代码：

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.pdf.PdfWriter;

public class GenerateSummonPDF
{
private String value1;
private String value2;
private String value3;
private String value4;   //this variables with constant updated string data

public  String getValue1()
{
    return this.value1;

}


public void userdata(String p1, String p2, String p3, String p4)
{

    this.value1 = p1;
    this.value2 = p2;
    this.value3 = p3;
    this.value4 = p4;



}
  public static void main(String[] args)
  {

  Document document = new Document();
  try
  {
     PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("C:\\Users\\User\\workspace\\enforement system\\Summon PDF list\\Serial No.pdf"));
     document.open();
     document.add(new Paragraph(getValue1()); //i need to print all the data here from the userdata
     document.close();
     writer.close();
  } catch (DocumentException e)
  {
     e.printStackTrace();
  } catch (FileNotFoundException e)
  {
     e.printStackTrace();
  }
   }
}

Answer 1

您需要GenerateSummonPDF的实例来调用非静态方法：

public static void main(String[] args)
{
    GenerateSummonPDF generateSummonPDF = new GenerateSummonPDF(); //create an instance
    generateSummonPDF.userdata("TestString1", "TestString2", "TestString3", "TestString4"); //some content

    Document document = new Document();
    try
    {
        PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("C:\\Users\\User\\workspace\\enforement system\\Summon PDF list\\Serial No.pdf"));
        document.open();
        document.add(new Paragraph(generateSummonPDF.getValue1()); //get value1
        document.close();
        writer.close();
    } catch (DocumentException e)
    {
        e.printStackTrace();
    } catch (FileNotFoundException e)
    {
        e.printStackTrace();
    }
}

Answer 2

您正在调用静态方法中的值，以便您收到此错误，只需创建一个函数并将代码放在那里就好了。

public static void main(String[] args)
  {
      createPdf();
  }
createPdf(){
  Document document = new Document();
  try
  {
     PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("C:\\Users\\User\\workspace\\enforement system\\Summon PDF list\\Serial No.pdf"));
     document.open();
     document.add(new Paragraph(getValue1()); //i need to print all the data here from the userdata
     document.close();
     writer.close();
  } catch (DocumentException e)
  {
     e.printStackTrace();
  } catch (FileNotFoundException e)
  {
     e.printStackTrace();
  }
}

使用get / set变量生成PDF

2 个答案: